QBXTSD STATES DSPJMMOT OF

Agricultural Research

Bureau of Batomlogj asad Plant Qisarantin®

of California Hawaii Agricultural Experiu&nt Station

Tervttorial Boayd of Agriculture aad

Pineapple Research .Institute Hawaiian Sngar Planters3 Association

iprSl 1 - June 3§9 195Q«

~ 298

ARSA CONTROL FitOJSC" — ifC&iC A-RGTBGT - 1-0-4. C* Fo Henderson, Leader

summary * akj.;a control project

Tests vein conducted to determine the effectiveness against

t£;9 Oriental fi'uJ.t j*ly of: WT a;o.xL:led by airplane at the rate of 2 pounds

of inseotiside lit 2-1/2 f;=JLloi.-j.« of total suspension spray per acre* These

testa resulted in only £&ir population reductions, probably because of

ijaadequ&te dosages, of 0IX.: &ii poor distribution of the DDT which is depositedslzcst entirely on !;he upper lea.-.' {surfaces* Biological assays indicated.

that the DOT reaictas ror^in-scl o;.*factive for at least two weeks» Further

a.irpla»io tssts are (jontenpla'ted :.n which higher DDT dosages will be

applied a3 amulsiOD .and ^uspsjnsion sprays, and in which a mild lure will

be included to attract tha .n.:.o» to the upper leaf surfaces*

Dilute DC'? spray applied by ground equipment was found to be

the most satisfacto'-y trsc-.tiusnt ugainst the Oriental fruit fly in urban

arses- Two £f.ppllcations \m\'& r;ui>.ie at the rate of 2«1 and 2<>4. pounds of

BBI in 106 and 120 gallons o:T su-tpmsion spray per acrQ5 respectively^

aod. population redu«tionfj of 9? »o 99 percent were achieved during the

period that these applications w^re bsing B?ade at 3-ueek intervalso

Larval, raaririgs i'ron bananas wid pipoyas suspended in the treated area

also indicated a control of 9& -y> ."LOO percent wiiich was maintained until

approximately five weeks £.fter "cxo last application was nade° At this

ti.se the DDT residuas viers* undoubtedly losing their effectiveness*

Op-r-z&tional costs w»re taken of <A\o dilute spraj* applications and the

two treatments averaged ^'uOO pf?..J acre-application* Although this method

of trea^nait was LiigoLy ?5UC23saf"LL in urban areas, the airplane will

■have "o be resorted to in wild host, areas where the terrain is usually

.?Gg~-spray tests demons ir«ted that this method of application

is very sasoessful ^or iK:iiatainisig low populations of Oriental fruitf3.y adults in urban ar-aaa as ion* as weekl^r applications are being madec

T.fesr a JJO^ HDT-solu-'iion mus appl.i@d at the rate of 1»2 gallons (2 poundsof actual O.DT) pe»r aero., thare was an average mortality of 89 to 98 percent

of the oagsd fli.?ias and' «v.luXt fly ;?opuiatic»ns were maiatained at levels

93 to 9f> percent lower -aisua the:?.? in the check &rea«> It wa3 also demonstratedthat, i^'hen DDT was applifid at *'Jv-3 above dosage as a fog spray, an appreciable

toxic residue occur3?od on ;r:?l:iaj2'. «.?itain 25 feet of the Tifa machineo

Houever, the residuo ajjpc«cvr3d to "vjeather of" quickly, and was not

(distributed uniformly over u'isj t::e«.»ted area* As this is a space-spray

treatment it remained ef-''e»c^iTs -\O? only a short, period following the .

last a.pplicjation»

A test was conducted to determine the effectiveness of penta-

chlorophanol applied by airplane for defoliating and dafruiting guava

trees* Two applications were made, the first at the rate of 506 pounds

of psntachlorophenol in 10 gallons of oil solution per acre, and the

second afc 208 pounds in 5 gallons* These applications proved very

successful in defoliating: the troes and preventing the fruit from maturing0.

Ho mature fruits were found in t3ie treated plot, as compared with 2,7&4

ripe fruits in the check* It is believed that a much lighter dosage would

be satisfactory for defoliating i:aid dafruiting scrub guava trees•

Fly movement studies \&re conducted to determine the percentage

of female fruit flies recovered in licFhail traps baited with fermented-

sugar lure t/hen released at an a:Lrporto It was found that 15 to 28 percent

of the files liberated 150 foot away from the buildings were recovered

in traps 9 .and that f?3 parcant of the flies actually reaching sheltered

areas wore recovered« From 16 to 20 percent of the flies required more

than 72 hours to reach the traps. When both mle and fenale flies were

liberated, 20% of the foraar and 10$ of the latter were captured* However,

4. percent of the females were recovered in a village about one m?J.e from

ths airport* It is apparent that MeFhail traps baited with fermented-

sugar lure can be expected to ca;ch only a small percentage of flias

reaching an airport or maritica jjort, and even soothe traps would have.

to be le£t up for more than 7?. hours*

Populations on lanai have shown a marked decrease during this

quarter* There was an avorage decrease of 84»3 percent when compared with

the first quarter of 1950 <> r&sgo reductions wore noted in all 9 study

araas subject to comparison with previous periods—-Kaena$ Halepalaoa,

Koole, Bonofr 1 and Bench 2» I'hesje reductions were also noted in all 6study arsas not subject to cor,-parison with the two previous periods—

Maunalei Gulchp Kapano Gulch9 Paj^Lwai and liiki Basins, and pineapple fields

5524, 55OB and 5502«

Since populations have gone down markedly in all study areas,

it may logically be assumed th.it there is only one variable involved in

the breading material supplying the flies to the island* The presence

of ripe guava fruit in Kapano Gulch and the Burma road area coincides with

the periods of high popul;?.ti:)r>s? in the nina-month period studied to date •

on Ianai.. Therefore9 at the present state of our knowledge9 it appears

that, guava on Lanai is the major contributing factor to populations in

each of the study areas all ovar*the island«

Kven though pop-.ilation.-s showed marked reductions during tliis

period,, they were noverth.idess concentrated in the Lanai City, Koele and

Kaymalapau residential ar^as (wiidi fruit trees) and Kaunalei Gulch (withtho banana sud pe.paj'a grcves)** Populations in pineapple fields wore downto practically aero during this \jeriod9 even in areas with ripening and

rips fruit* Alsc3 these aroaa siiowed the highest percentages of female

files• The absolutes weekly irKiadjauci and/or minimum temperatures, as noted^ for Laiiai City, did not a;c<pear to affect populations, for the nine-month

I . period uiider study.-. The averewpa weeldy wind velocity for the nine-month

300

period did not appear to affect populations as a whole» However^ the

llcPhail traps in Lanai City which v/ore sheltered fron the wind showed

higher catches than unsheltered onea*. Alsop studies in the previous

quarter, when more flies wore available for comparison, strongly indicated

that flies iiere more active in pineapple fields during less-windy periods,

as noted by catches in FIcFhail traps«

Citrus trees appear to attract the fruit fliss to a greater

extent than others, all other factors being equal* While the infestation

in citrus is comparatively slight, the flies do conplete their life

cycle in this fruit, and it is possible for a strain to be built up which

would be potentially dangerous to citrus on the mainlando The infestation

in citrus during this quarter was as high or higher than in the previous

two quarters, notwithstanding marked reductions in overfall populations•

The infestation in tree-ripened bananas was lower than in the

past two quarters" However, this reduction was slight when coiapared with

the marked decreases in- populations on the island*

The percentages of female flies were above 50 in all study areas«

In the previous two quarters, they ware below 50 in the residential areas

and liaunalei Gulcho Evidently the male dies off sooner» The percentage

of females was lower in the residential areas and Maunalai Gulch than

they were in the host-free* areas as Kaersa^ Kanele, and lialepalaoao

Certain traps in Lanai City showed comparatively high populations

consistently throughout the entire study period* Also, some traps were

consistently low* Evidently climatic factors or presence of certain fruit

trees affect activity in local areas*

301

1-0-4-1*0 - HJSECTICIDAL C0KTR0L STUDIES

Effectiveness, pfiMI)DT suspension ^, pjQ^^y^a^pla

(Hendersons Gammon., Kang and Smith}—-As previous tests with tho airplanehave been in small areas subject to rather heavy reinfostation with fruit

flies from outsida sources (Wahiawa gulchea), it was felt that this methodof application had not received a fair test when compared with dilute

spray applied by ground equipment in an area having a negligible amount

of reinfestation© Consequently, two areas were selected for additional

airplane spray tests* one the 300-^acre village of Kahuku which is on

the windward side of Oahu about 2 miles north of the dilute-sprayed

village of Laie, and the other the l80~aere village of Ma5.ll., on the

western side of Oahu. The former was selected as an ideal location with

respect to th? amount of reinfestation, which should be quite low and

comparable to that of Laiec Heavy winds usually occur at Kahuku, making

tho airplane test at ti:is locatioii a drastic one* In contrast, the degree

of reinfestation should be somewhat higher at Maili5 and much lower wind

velocities should prevail*

Before treatment, the N-25 Stearman plane was calibrated to

apply 2-1/2 gallons of DDT suspension spray (4 pounds of 5Q# wettablepowder) per acre whan travelling at 37 miles per hour with a swathwidth of 80 feeto Forty-seven l/8-inch nozzles and a liquid pressureof 30 pounds per square inch were required to deliver t«he proper gallonageo

The 50/? DDT powder available (Santabane) has a greater amount of wettingagent than desired for sprays of this concentration, but nevertheless,

the mixture could be used without any appreciable difficulty« Penco

WD-50 would be a much more satisfactory wettable powder for future use

in airplane spraying, but at the time of these tests was not locally

available*

Ifehjiku^tegtgo—Tlie first airplane test at Kahuku was

initiated on May 25 when DDT was applied at the rate of 2°1 pounds

(4»2 pounds of 50$ wettable powder) in approximately 2-1/2 gallons oftotal suspension spray p3r acre. Application was begun at 6s30 a»Q«

and completed at 9?00 aom»j> using 1,280 pounds of 50% DDT powder on

the 300-acre urban area* Wind conditions were not ideal for this type

of treatment« At. 5 s30 a«m* there was a wind velocity of S Mies per

hourj; at 7s00 a»nu, 9 miles per hour; at 8s00 a«m«j 10 miles per hourj

said at 9;00 aeinoi, 12 miles per hour* Although there was considerable

spray drift due to the relatively high wind velocity^ rather detailed

observations made subsequent to treatment indicated a fairly good

distribution of the spray particles« The amount of coverage on the

leeward side of buildings and hedges was quite surprising, probably due

to the action of air currents* The effectiveness of the treatment was

determined by (l) adult fly population counts from 15 McRiail trapssuspended in the treatment (kahuku) and check (lauula) areas, and (2)larval roarings from papayas -arid bananas suspended in l/2Haesh wire-screenbaskets- in the respective areas (15 baskets of each fruit) e Populations

• «=° 302 •»

of adult flies in the treated and check ar^as at intervals before, during,

and after treatuent are shown in table lo .

Table l.~Sffectiveness against D» dorsali3 populations of

DDT suspension 3pray applied by airplane*

Kahuku, To H», 1950.

Treatment

dates

•amt

«=.

(Ml

on

5/25

6/15

Trapping

period

4/18-254/25-5/2

5/2 -5/95/9 -165/16-24.

Mean

5/24-315/31-6/76/7 -156/15-216/21-28

6/28-7/3

Flies per

Kahuku

17-0

7o7

5o0

5-1

2o9

7o5

»3

•3Io2

1-5

0c5

1*8

trap-day

flauula

13 »8

Ilo8

10.1

16*310o8

12«6

9.18oO

4*6

6o74«2

3-5 ,

Percent

control 1/

CSV

96

9456

62

80

14

\J Corrected for population reductions in check

As shown in table 1, there was an average pretreatment population

of 7*5 flies por trap-day in the treated area and 12o6 in the check*Immediately after treatnent 0*3 fly was caught per trap-day in the former

and 9<-l in the latter, or an indicated control of 96 percent when corrected

for population reductions in the check° The same degree of control "was

maintained for the second week, but on the third week after treatnent

control xjas reduced to 56 percent»

The second airplane application of DDT suspension-spray at

Kahuku was on June 15, with DDT applied at the rate of 1*96 pounds ofactual insecticide (3*9 pounds of 50$ wettable powder) per acre, or atotal of 1*175 pounds of wettable powder over the 300«acre village <. Wind

conditions vqtq again not very favorable for this type of application,

as there was an average wind velocity of 11 miles per!hour during the

treatment period» As shown in table 1, the application resulted in

relatively poor control» During the second week following application

the degree of control had increased to 80 parcent, but one week later

almost no control uas indicated*.

In addition to the trapping cf adult flies, larval populations

were determined from bananas and papayas suspended in the treatment and

check areas for one vioek (May 25 to June 1) inmediately after the firstapplication.. Hearings from those fruits indicated 0»3 larva per pound of

banana in the treated area and 53»5 in the check, or an indicated, control

of 99«4 percent« The rearings from papayas gave 1«2 larvae per pound of

303

fruit in the treated area ar.d 7«9 in the check, or a difference of 84«>8percent* . During the some period there was 0*3 adult par trap-day in the

treated area and 9-1 --n the cheek, or a difference of 96«7 percento Asstated elsewhere in this report, however, little reliance nay be placed

in larval-population estimates as determined from ripe fruits suspended

:ln an avea of this bype, except where extremely low densities are

.involved* Houever, it is possible that a, population of 0o3 fly per

trap-day would come within this density category •

Bl&4J^&£ £>il%st airplane application at 1-iaili was

or: Kay 27 when 750 pounde""of 50$ wettable JDDT pokier wore employed inspraying the ISO-acre area, or 2*1 pounds of aetial W£ (4*2 pounds of50% wettable powder) in 2-1/2 gallons of total suspension spray per acreo

During treatment tha wind velocity ranged between 2 and 7-1/2 miles perhour* and observations made scon thereafter indicated a fairly uniform

insecticidal coverage- As would be expected, however9 the spray deposits

were practically limited to the upper leaf surfaces to The effectiveness

of tiiis treatment, as at Kahukn, was neasured lay trapping adult flies ona comparable basis in treated and die ok areas, and rearing larval populations

from bananas and papayas suspended 5jn the respective areas ° The results

of the fly trappings are shewn in table 2o

Table 2»—Effectiveness age.inst Do 3sr§g,y& populations of

DDT suspension spray appliec; bf airplane•

To.Ho 1950

Treatment

dates

6/15

Trapping

period

5/3 -15t>/X5"22Mean

5/22-295/29-6/56/5 -126/12-0.96/19-26

6/26-7/3

Mail.-

25 oO

18.1

21*6

12,2 2/2«9

4*12©9

1*2

1.2

Narakuli

30-4

£6*2

.Uoli 16*8

9«3| 5-5

Percent

control 1/

no

_«•_ ^

•

72

66

57

69

! ?4

1/ Corrected for population reductions in check*

2/ Including some pretreiitaent insects•

As slaoian in table 2S tb/.re was an average protreatment population

of 21*6 flies per trap-day in th/^ treated area, and 30 »4 in the check*

During the first full colloctio/i ueek after treatment (I-Say 29 to Jxme 5}there i/as an average of 2*9 fl5.es per trap-day in the troated area and 14*1in the chock,, or an Indicated control of 72 percent wh€»n corrected for

population reductions in the ciiecko

304.

The second treatment at Maili was on June 15, when 2.1 poundsof DDT were applied again in 2-1/2 gallons of total suspension sprayper acre. During the period of application the wind velocity ranged from3 to 9 (aveKage 4.9). miles par hour* Although a fairly uniform depositwas achieved throughout the treated area, a small central portion oftiie village was apparently "missed" by the spray deposit. The resultsof this treatment ysare not very satisfactory—69 percent control for thefi:?st full week's collection after application of the insecticide, followedby 74 percent dux-ing the socond uaek

The larval rea.ving.3 .from suspended bananas and papayas alsoshowed poor control at Maili, Fifteen baskets of each fruit were suspendedin the treated and check areas from June S to 19, and then placed inroaring flannels for ths emergence of larvae. These rearings indicated7«3 larvae per pound of banana in the treated area and 9<o in the check,and 21*5 larvae per pound of papaya in the- treated area and 11*9 in thechecko During the same period there, was an average of 3*5 adults pertrap-day in the treated arsa end 13O0 in the check. Apparently, withinthis population range, thore was no significant correlation between adultand larval fruit fly populations- These results further substantiatetne conclusion that the insectieidal treatment was not very satisfactory-,

To determine the lasting qualities of the DDT suspension sprayapplied by airplane, a rnsnber of uniformly treated leaves in the sprayedarea uere marked for future collection. One day after treatment the firstseries of loaves was collected and placed in wire-screen cages with onehundred newly-trapped male fruit flies. Similar foliage collections werelaaete 5,11, and 19 duys after treatment. '£he mortalities of flies confinedon these foliage samples are shown in fig., 1»

A& shown in fig. 1 the DDT residues which had been exposed tofield weathering conditions for 1 cay were very effective in killing thscaged flLjs., There was e mortality of 70 percent 12 hours after.installingthe test, 93 percent in 24. hoursP and 93 percent in 48 hours. Littleapparent difference 5ji effectiveness was noted between DDT residuesexposed for 5 and 1". days in the field. When the results of these twoweathering periods were combined the average mortalities after 24, 48 and132 hours of confinement were 81. 95 and 100 percent, respectively. After19 days of weathering the-»e viaa a significant reduction in the effectivenessof the DDT residue. In this case there was a mortality of only 62 percentafter 4^ hours c<£ confinensnt, and #3 percent after 6-1/2 days.

The results of "^.e airjOans tests with DDT suspension sprayat the rate of 2 pounds of insecticide per acre were nc-t very satisfactoryIt is possible that these poor results, at least in part,, are due to thsdistribution of the DDT rwsitlua which is deposited alnoat entirely onthe upper leaf surfaces. Further tosts are conteraplated. in which higherdosages of LVP are to be used by airplane, as this'is tiie only tvpe ofeqflment- available for u.m© ::n large areas which jaust receive insecticidaJ

t

FIGURE X Effectiveness o

application * H

speaslon spray residues

H* - 1950'airplane

i.< ?

-..:.

EH

M

O

33

&:

D A X 6

-v- 1 clay after treatment wfeea foliage ftas collected

■ U3; «

306

Tests are also ooirte?aplated in which a mild lure will be added

to the spray in. order to attract the flie.i to the upper leaf surfaces

uhere the insecticic-iU. deposits occur* It is also possible that the

application of insecticides by helicopter might result in adequate

cowrsges on the under leaf surfaces, and this possibility will be

d as soon as such ••jquipmai/.t is available*.

mon. Henderson and Kang] r--~Dilut9«spray tests were initiated onK'ircJa 15j at Laie, a 125-aci'o /ill&ga on the windward side of Gahu, to

dei>3:ccdne the effectiveness of thi& type of application for controlling

fch» Oriental fruit fly in e. typical urban are&o This village was selected

for treatment because of the variety of fruit fly hosts present, the small

dagroe of reinfestation eicpeefad from outside sources, and the cooperative-

ness of the local authorities.. The effectiveness of the DDT spray

applications was measured by (l) weekly catches of adult fruit flies inKei-aail traps baited with fenrantec.-su^ar lure* which ware located in

both treataaar.it and check ■weta1} site: (2) larval rearings from banana, and

papaya .fruits suspended In !/.<:• »:tr.d:. oeah wire-screen baskets throughouttiie two respective areas=■ The. ec-nipnent used in spraying Laie was a &25~

gallon Friend dilute-sprs;/ FKiciiit.e^ operating at a liquid pressure of

37'} pounds per sqpas-e inch, and eqidpped uith two 300-foot lengths of hose

having orchard-type Bean ;3pra;y neszl^s attached»

?hs first t.rsatnent at L&iG.uas applied between J-iarch 15 and

30 f, using a 97^ wattable UDT irvwdei" at a concentration of 2«14 pounds

(2 pDimds actiaal DDT) per- 100 gallons of total spray mixture, appliedat thg: rate of 120 cellos.ss (;2«4. f.ounds of DJT) per acr©o The results of

this application w©;;e discussed In the First Quarterly iteport, pp» 335-338,

and rilso appear in table ;$ and rig$:.ra 2 of the present rejjorto

As shown in tafcle 3, there was an average pretreatment population

of 26*9 adult fruit flies per trap-day in the treated area and 22*4 in

the check (Hauula) during the period February 2B to March 21• On April 4,5 days after completion of the firgt dilute«-spray application, there was

an average of 0«2 fly per ti^ap-day in the treated area and 14*2 in the

check, or an indicated control of 99 percent« One week later 0«l f3^r was

caugjit per trapniay in tho former area and 7«7 in the Latter, or a control

of 99 percent«• It :1s of interest that;, on "the third ueek follouing

trea1a?.ent (April 11) there ik?.& ai; indicated control of only 91 percent*

!The second. DDT '.Iiiut(?5«£U&p3n3ion-spray treatsnant was applied

at Laie en April 13*"24,-" u;*iri# ffffi w^feteble DDT powder at the saneconoontTe'ylon as during tiie ;?.1..?st application * On tlais occasion, however?

only 106 gallons; of srpray mi^'ire yere applied per acrOj, or 2ol2 pounds

of actual DDT« It vill bj lui't^a fxjoia table 3 and figure 2 that control

of the Oriental fru:Lt fly wajr. 99 jxiroaiit for a period of four weeks follou-

Ing the second inaeeticidal a.£'olic&.tion* Subsaqueiatlyj the weekly trappings

indicated control-? cf 97? 91- c'C^. v'0;? 69 and 19 percert^ These reductions

in control were prolably duo to the- iscreased effectiveness of the DDT

residues.* which faille<l tc ki'.iJ. &s i igi a percentage of the reinvesting

Table 3.^Sf£ect4veneso of DDT dilute- suspension spray for

controlling D° j3££S&y£i iia a& urban area- Laie*OahUj, T. H*. 1950

Percent

control 1/

J5/33.-6/76/7 -156/15-21 ■6/21-28

1/ Corrected for stipulation reductions In the check*

FXCUIIE 2

-*.a an lii'

of WT dilate emspension gpragr against D,«

es;, !*•?!«, Oah», T. 1L 19-50

'O

- 309 ™

fruit fltas* i.t is' appe^e-rrJi., however, that the DDT diluts-spray treatment

was very sucoassiCul for controlling populations of fruit flies during

the period that dilute spray applications ws??e being made at 3-week intervals»

In addition to the .-adult fruit £!$■ population counts in th©

-treated and check areas» larvial rear&ngs ware also made from bananas and

pvp&jras suspended in trees within the respective areas (thirty baskets$£ eaofc. fruit in Lai® and 13. .in H&iiula) •• Th.8 results are shown in tabX© 4*

first -post—treateint hearings were from bananas and papayas

suspended in the field for tba period' 1-ferch 31 to April 14* During this

Interval the bamnss • afecaivad ai: average infestation of 65*5 larvae per

sound in vJis check area and 1*0 in the treated? or an Indicated larval-

population control of 9^*5 percent« The papayas contained 24 »4- a&d 0o02

larve.o pas? pound in the tno rssj-jsicbivo areas, or a control of 99«9 percent*

Xhe thre.a. subsequent resringe d,ov/ed controls of 99«7j 97«7» and 91 percent

An be^ajms and 100,, 100 a&d 83*? paroent in papayas* The last rearings

(91 qj& 3Bo5 percent control In bananas and-papayas5 respective!^') werefrom fri;.:l"«is suspended bet-we^r- .fey >25 and June 'l««iaore thati one aionth after

■ihs last- insecticidal troatsae-at was applied <• At this tinie the DDT residues

had evidantl/ begy^i to lose their effectiveness a and thus ar$ increased

jiumiser ©£* flies ysre sur-vri^/ing t-reattaont and depositing eggs in the

sussendfcd fruits- Larval rea:rfjr..gs ara the feesi measure of over-all controls

as tfe©y indicate tb.e abuudones c-f gravid females which had. siirvived tba

tnt. sufficioirtly t.o depaaj'.t egga in host fruits*

-Operational co^ts -wer? determined for tlis two' dilnt@«»spraj/'

applications at Laie and tfaa ic-epalts included in tables 5 and 6»

lp 4*-"-n®ff©«t;5.yea?j£!s of I3.DT dilute suspension spray in

jpsduc-iiiK XsiTTcil >x)pulations 3j\ suspended fruit»

Laie. Qah?i, T> IUP 1950•

vvmunimram:*

^3SS§fe™^.rEZSSM'2&«4-«J^^r?

2/27-30

A95

/6

•32.5

•0

o9

fe^

O ■-•>.:

1 y »• «-

p too

! 98.9luoa

I 53-5

24 »44-»

Percent

99*7

9?o7

91.0

99*910C-o0

100 iO.

Table 5*—-Tabulated ixcssrasay of spraying operations at Laie«

2'feirch 15 »> April 24? 1950«

Blocks

First

Second

. j .O.I.OC.K.S |

15 | 176o5

15 I 132.0

Totals 30 3083-*

yinn bin©

j Sprayer-

■

I 40o

32 c

72 0

5

0

5

Gallons of spray

Total

14,

13,

23,

875

300

175

! Per sprayer-

! hour

367

416

389

Per acre

119

106

113

Table 60---Costs of applying DDT dilute spray at Lale<15 « April Z<., 1950 c,

jj Cost o£ op3rations

airaber f Labor- } W&beri ^teS^lsTMSitSiaSce

First

Second

Totals

I 176.50

132oC0

303.50

- 311

As shown in table s}9 the second spray operation was accomplished

much, more quickly than the first, probably due to the higher efficiency

of the spray crew after having had previous experience o It will also be

noi9d that a slightly lower {jallonage of spray was used in treating the

area tfa© second time* Even so, it is believed that a more uniform coverage

ws.ji achieved during the second treatment<, On the first occasion, too

much time was sport in treating individual spots, whereasp on the second,

the jspray liquid was spread war® uniformly over the entire area* One-

hatdred^nin.eteen gallons of epray were applied per acre (2<>4 pounds ofactual .00T) during the first trea'-j-ment and 106 (2ol pounds of DDT) duringtb.e second o

The costs of applying the two insecticidal treatments are shown

in. table 6« The greatest expanse vas for laboz1, followed closely by that

of materials« The first application cost was $3?31 per acre and thesecond $2nG9, or an average of §3*00 par acre-apfgllcation1 for the twotreatmentso

It is apparent -that- DJI dilute sjpr&y applied by ground equipment

was very satisfactory for controlling Oriental fruit fly populations in

a typical urban area* As bo attempt- was made to apply a complete

insecticide! ■ coverage9 It is apparent that the insect moved arouhd

sufficiently ■to quickly oome in contact with lethal dosages of the insect

icide » It is possible that even a lighter application would h& adequate

because of the characteristic of the insect to move about* This method

of application, although highly satisfactory for controlling the Oriental

fruit fly under cex'tain' conditions is limited to rather flat, easily

ascessiblo terrain* The airplane will have to be resorted to for treating

wild host areas which usually occur on rather rough terraino

Effectiveness, of DDT fo^g-pray treatment in residential

areas (Henderson. Kane* Gajucacn stud Smith) i;«««Ia the' previous report(First vimrterlj' Report ppe 324^334-) j prej.iminary tests with the tifa

fog-^sprtiy me.chine were discussed* The first test was at the Damon

trad;3 an uittbaii area on bh<2 lee^-RU^d side of 0aliu9 where an 8% DDT~pyrethrum

solution -was applied at the rats of. 0c3 pound of DDT per acre*. This

treatment, resulted in a 33 percent mortality of the cag©d fliss and a

reduction of 79 percent in adult populations as determined from the

McEoail traps* In the second 'oeslv conducted at Damon, a 15% DDT solution

was applied at the rate of 0o9 pound of insecticide per acre© It was

decided to discontinue the use of pyrethruai as the advantage of a quick

S!Zoioekdoijaw was not apparent in outside treatments of tttis type* Wind

conditions vave about the s-iias as during the previous test, or a velocity

of approximGtsly 3 to 4 miles per hour- There was an average mortality .

of 73 percent of the caged fl5.©o end a reduction of 89 percent in adult

fruit fly populationso Frora these, data it, is apparent that an increased

dosage o.f DDT was associated w5,*i;h increased effectiveness of the fog~3pray

treaiiiaenu• The promisitsg jrasults Indicated the desirability of further

testing this tyrpe o.C application i.*or use in large-scale operations ■against t3.ie OrrlentsaiL fruit fly in urban-

In selecting a si'se for additional tests with the Tifa fog-spray

machine* the village of Vai&nae was chosen as the nost desirable location-

This, is a 150-acre tfillagQ on the viestarn side of Gahu., lying befcueen the

W&isiaas mountaias and the; chore* Iliis area should have less wind movement

than most- ouisr ;port:Loris of tiis Island^ and should be isyl-ject to much less

relivestation than comparable urban areas on Uie leeward side of Oalnxo

.tO-tlxough villages on the vrfxid'fard side of the island wo-uld have less .

relnf9static::i., wind ■condition.--i ih&re< are not very favorable for this typs

of applioati^nc The nearly v.-aiaf-Q- of Manakulijj 5 miles southeast of

ser?ed as a check aroa.

EJ c:T the £og~8pray treatment at V/aianae

d by (l) 12^hour iaorte:=.3:% coiaits of jaale fruit flies sonf?-ned

s i-il^e-screen c-:riges ••■.it strategic locations throughout the treat»

nd check areas during the period of applications (2) adult populationsLa. she tvro risspective ars^a o-sr:^-: ctn ;S-iiour'period following treatment,

ars rietertinned "by trapping i'l.i.:3ff vi'..th fsrmented-sugar lare in McBiail

feaps? and (3) liu^»u:i re?irii?.£ i3 £:roni banana and papaya .-fridts suspended:ln ;i./2-4n(!h id2'©~sc-i?-3©n. bat?k€'is y:.tai.n the treatnent and check areaso

Four v*^e^.;/ fcg«spr:3j avsp-lications were made at Waianae from

May 22 to Jims 14. "csing "-ho f. ill; o^fing forr:.ulation applied with the

TiEk HacMne belon".«;:lnp * to %hi- Ts^-'itorial Board of Healths DDT? 150 pp-unds;xplom, SO gallons^ dissel o:".L., 40 gallons| and #50 engine oil? 40 gallons^'?ii3 engine, oil vas' added to iLz^ye^a the specific gravity of the solutionwhich was lowered 7c«y the -addition of such large quantities of rcylene*

'Cha rasul-iing 180 gaUons o:r solution (20% BDT by weight) was applied toth-3 150--'&ar& village at th& rite of 1U2 gallons containing 2 pounds of ■

DDT par aore« Application va>s liade la the late evening, and early morningi-men'w^d vsloci-bies wars a,? low ^.s possible» Approximately 6 hours wererequired to treat th© a^r-^a ^ ;;«iich -application, or appro:cimate.'ly 25 acres

par haurv

Tl:.s fir-st insacti.-s.-.^L:. fog-spray application at Uaianae was

O3i ;:&y 22-2;: o Tre^itsien-G was a]:nlJ-.ed- between 11 p*m« and 5 the following

aor-i:,ng with w±sd veloftltiars Ki:jg:i.ng from 2 to 6 miles per hour duringthe period o liomsdiat^O.y bt3'.P«rjrj? apfiying. the r«Gsecticide3 36 wire-^scrseneagas of appr-o.2d.mately Sv 1.1:2:.e WwSt file a each were' suspended in foliagein the treatment area, aad 7 5.17. 1&e check*. As soon a,s the application

was eoiapLl..stg-d.j» the cages w?:::- !; :-o:-:irr.>t to th© laboratory end held fors\Abseque.nt- mortal!^y couat3r. D-ir-ir.^ ths intervening 'period, the insects

war-3 pTDTid^id vitii .food aaii i; a^r r. The lacjrtalitias -agisociated with this

treatment ajj;e i bl 7

As shown in tabla '■).. v'Oo? psr-cent of the caged flies were dead12 flours sifter treatment;, ;il-b coiayilste tnortalities- in 29 of the cageso

Apparently,, only 1 ?age -vsafi ■■■«D;.xi«'Uily ni-issed by the Insacticidal. fog,

ijp 5 others had iln^ds;-1 d:1^ tr

Jiiyt prf.or to ?ippX..1r>;:.-i:.S.oiii, sXL "Insacts were namoved from the

!5 McHiail traps located in ix'ki ibe tres.tra.ont and check areas and the

ti-tps bagg©^« "'Braadiafelj f■ iUa'-'si^ application the bags-were removed^

Table ?»—Mortality of caged nale fruit flies * !£\fa fog-

spru^v applicationc Waiianae, I* H*? 1950s

I Firstv test

Cage fTolSlTTSSnt

'7hird tost

S/5-6Total

flisa

Total

fliesmortality

100

100

100

100

100

100

100

100

100

100

100

100

100

WWRirSiliJ ».'»<Mriul£itZUr.<i'«

■jhich caused ziexrs £!±oe:Cood, slight rain forzaeci syrup

to becone stuck»

314

a/id the lure thus exposed for a period of B hours. During this time an

average of 0*2 fly psr trap wis caught in the treated area, as compared

uith 14 in the check, or an indicated control of 9806 percent* These

results are particularly interesting as the treatment iias applied under

conditions which were not considered ideal for "fogging"* .Hot only were

wind velocities up to 6 miles par hour recorded for tha treatment period,

but the insscticidal fog appeared, to rise rather quickly after leaving

the nossle of the Tifa machine* As spraying proceeded during the evening,

caged insects were examined at intervals* and in most cages the insects

appeared to be affected by the DDT- This was even true in areas sprayed

under the most unfavorable -vrlnd conditions«

The second application at Waianae was made on May 29-30*

Treatment was applied between 9%QQ p.»m« and 6 the following morning,with wind velocities ranging from 0 to 4 miles per hour- During application,

the insectieldal fog was observed to remain close to the ground for long

periods of time* In. general, corj^'dons were much more satisfactory forfogging than during the first application when wind velocities up to 6miles per hour were recorded« During 'the treatment period, 22 wire-screen

cages of approximately 30 malls fruit flies each were suspended in foliage

within the treatment area, and 10 in the check* As -shown in table 7,there was an average mortality of 92«6 percent ofthe caged flies 12 hours

after treatment• Apparently no cages ware missed entirely by the inseeticidal

fog,' although 3 had received inadequate treatment* McPhail trap counts

taken on May 31, one day after the fog-spray application (and includingsome pretreatment flies) showed an average population of only 0©8 fly pertrap-day, as compared with 38 in the checks, or an indicated control of

97»9 percente

The third fog-spray application at Waianae was on June

Treatment was applied between 10 p*m« and 5 the following morning with

wind velocities ranging from 2 to 8 miles per hour* During the first

part of the treatment period there were extended gusts of wind averaging

4-5 miles per hour, and towards the end a wind velocity of about 8 miles

per hour* Before beginning the ineecticidal application, 23 cages of

approximately 20 male fruit ilias each were suspended in foliags within

the treatment area, and 9 In th3 check* As shown in table 7 there was'

an average mortality of 89»3 psrcent of the caged flies 12 hours after

treatments. It is also, of .interest that only 4 flies entered the McEoailtraps in the treated area during a 2Q«hour period following application

of the fog-spray«

The fourth application was on June 13-14 with wind velocities

of only 0 to 4 miles par hour'—the most favorable condition experienced

at Waianae for applying a fog ©pray- treatment • Before application of

the insecticide, 2X cages of approximately 30 niala fruit flies each were

suspended in the treatemfc area ami 4 in the check» Because of the use

of raw sugar as food for the flies, which changed to syrup following a

slight rain, inany of the che^k flies were stuck to the cage and consequently

injured so that a mortality of 14•6 percent resulted • Howevexj even when

the mortality of caged flies iii the treated area h&s corrected for this

abnormally high natural mortality there <was a net mortality of 93*4 percent*

315

Jt is also of interest that, on Juno 12, 80 percent of the female fliesin the check area vere gravid > as compared with only 40 percent in thetreated axea»

To determine the over-all effectiveness of the weekly fog~spraytreatments applied at Waianae, KcPh&il trap counts wore talcen in thetreatment and zheck areas before., during, and after the application

period. The results of these population counts are shown in table 8*

liable 8—-Effectiveness against adult EU dorsalis of DDTfog-spray treatments* Waianae, Oahu, T.Hc

Treatment

data

O 5-6

Trapping f

period *" Waianae

5/22-295/29-6/56/5 -3.26/12-196/19-26

6/26-7/3

•9

•8

.6

.91.9

Nanakuli

16 e8

9-3

5-5

6,6

Percent

control 3/

1/ Corrected for population reductions in check*

949395

9382

68

As shorn is table 8 thara uas an average pzsetreatiaent population

of 26 O8 flies per trap-day at viaiaxme (14ay 8-22},,. and 2-0 «4 at Nanakuli«During the week following the first application there was an average of

1*5 fliofi per trap-day in the treated area and 26•2 in the check, or an

indicated control of 94- percent .i islthough x^opu3-^tions continued to decrease

in the check as wall as in the tares.ted area, during the treatment period,

there \m?a indicated controls of 93., 95, and 93 pareont following the second,third,, and fourth applications« Trapping records after tlie last treatment

indicated a eon-trol of only B? percent for the first week and 68 for the

second,, showing that paptii-aticue w«ro beginning to increase in the treated

area* This is to be expected for a space opr-ay such as ti:is where DDT

residues -auce not an important factor«

To determine wh©%b!ier or not any1 appreciable toxic DDT residues

were present on. the foliag© rollowir.g a fog-spray application, leaf

samples wore collected at VH.r3.ouc! .intervals from the V/aianae treatmentarea for biological assays■* /'II leaves used in these 'tests uere from.

- 316 -

sites where there had been complete mortalities of the caged insects, andwere from trees and shrubs located in the front yards of properties atdistances of not more than 25 feet from the Tifa machine. After collection,the leaves were suspended in wire-screen cages which also contained food and

water for the insects, and 100 newly-trapped male fruit flies introduced*

Foliage collections were made immediately after each of the four weekly

applicationsp and just prior to the second and third* Mortality countswere taken at frequent intervals* and the results are shown in figo 3©

It is apparent that there were appreciable toxic DDT residues

on the collected foliage following a Tifa fog~spray application e Leavescollected one day after the first application had sufficient toxic residues

to Still 95 percent of the caged flies in 12 hours, and all were dead after

26 hours* Leaves collected 5 days later had lost much of the toxic residue,as indicated by a mortality of only 20 percent after 12 hours and 33 percent

after 26 hourso The residue fron the second treatment was less effective

than that from the first, -as there was a mortality of only 63 percent in12 hours and 86 percent in 260 With loaves collected 5 day3 later only

40 percent of the flies were killed in 12 hours and 72 percent in 26 hours oThe third treatment showed 45 percent mortality of the caged flies in12 hours and 72 percent in 26 hours* Very poor mortalities were associated

with the residue from leaves collected 5 days later* Foliage collected

immediately after the fourth application resulted in mortalities of 25

and 52 percent 12 and 26 hours after treatment, respectively* From these

data it is apparent that toxic DDT residues were deposited by the Tifa

fog-spray machine on foliage at least 25 feet from the spray nozzle»There seems to have been very little accumulative effect from the four

applications however, indicating that residues of this type weather veryquicklyo Also, the side~delivery method is a very ineffective means of

applying uniform deposits over large areas, and it is possible that more

even distribution of the insecticide could be obtained with a helicopter

equipped with a Tifa fog-spray head and flying uniform swaths o It is of

interest that biological assays also indicated just as effective residueson the under as on the upper leaf surfaces when application was made with

the ?ifa fog machine o Leaves collected in the field were placed in cages

in such a manner that only the upper or lower surfaces were exposed to

the confined insects* Mortalities of 33, 72, 86 and 92 percent (average72) resulted from contact with the lower surfaces after 48, 72, 96 and120 hours respectively, as compared, with 30, 56, 63 and 67 percent (average53) for the upper surfaces»

Bananas and papayas were suspended in the treated and check areas

to determine the effectiveness of BDT fog-spray application in reducing

larval populations in the exposed fruit* The fruits were suspended in

l/2-inch mesh wire-screen baskets in the two respective areas for

ajjproxiinatoly one week after the first application, and then placed •.

in rearing funnels for the emergence of all contained larvae • It isevident that this method is not adequate for indicating populations of

fruit flies, at least at the levels dealt with in this testo For example,

0»9 fruit fly per trap-day in the treated area at Waianua was associated

with 11«3 larvae per pound of bananas, whereas 14°1 flios par trap-day

in the check area were associated with 37*1 larvae px* pound of fruit*

337

FIGURE 3= Mortality of male D. dorsalle confined on foliage treated with

:.tifa macb ins« Waiaaae Ho Mey 22 to June 14, X95G-

IOC

7 J.2 u

H*imeraL«&pplication sunbar«

- FoXlage collected iBaaed3^t©\7 after treatment.■ - Foliage collected 6 days aft^r tpeaianent,

In ths former case there was; & ratio of 12-.larva© par adult fly and ini:ha latter- aaly 3° No lsrvs.a ware found ia papayas suspended in the

treatsd sxea as compared id.-J.li 9*5 per pound in the check° It is apparent,.howvar, that little rolianca may "be placed In these data*, However, the

suspension, of bananas ia tre^ie.:*. areas would b8 an excellent index of

:uifestat:-.cn following a drasfr'.a control program, to determine if any fliesia33?G present 3Ji the area* Thi.st via a demonstrated at Laie whero dilutespray" ha 3. reduced population to eccoreinely low levels«

Fog-scray treatmentm *sy be applied economically<> The average

GOH-; of fche treataaacts at fe:uiii3& was 7 pa? acre-application, includingcost of* ns.ttvri.als, operators: .tor the equipaent, services charges, etc*Another actron^age of this typ> of application is the speed with which large

■areas may bo covered efftil

fi^citiKg, cf jjuavg. to .eliminatejC£ulJLS2.J" ^JT^T' f Oitl fit

DeficitiKg, cf jjuavg. to .eliminaj£JLS2.J^J&(Gammon, Hen&srson "and ^agJT'^JaT'areas of Oriental fruit fly host vegetationifS-hh "Jittle or no econoni* vs'.us? such as guava thickets (or stands ofvJ:»d *^esfry in Califarak? sthould bho fruit fly reach the mainland;, the»is^ of herb'lcidal or dei'i-oi/l-i?^ sprays would bo of value in reducing fruit■Hy copilot-Lone by eliminatixi;; certain host fruits. 3ji drastic populationooirtToi on t?vi upland It Ka:r h^s desirable to remove-all host fruitsctay^np cbx'tain years in ssuc:h areas* Such a procedure would certain^ beranrib mors eocjoondcal than fi^qu^nf- application of .inseotioidal spraysj>->-*v>c*jfT>y Vi largo ai*sas pp:3.:?s€?ly populated with host trees. Also, i.^o^r'prd<rVi3d 'ixban areas« ci'a^tic pc>pula;bioa suppression ■ might involve•fcViR rericwal of all fruits vrlthcvt destroying or injuring the valuaaLe host

^s- TCiiis --jou-ld bs a laal.t**;:? of sanitation piroeedure such as the remove.-?rTJif g by hand ^ckir^, Oa Un&U vAare. certain stands of guava are ^

to fruit tree plEjrt.lntfs for the purpose of stwdyinc area contrtu _the same result.!? ycvlA be achieved by the use of defrmting(Toft rer^y^l of rrxits by hand would be imj^^c-bicable in suen

as*} iis» no ctetoultlntf hoT:oc-aar: %«2?e avuilabl© for use against gua/vas,vas deo.idad to teat aefoIU-mts which would have the effect of causing

r'ao frirK to dry up on tha -jr-ae or drop to the ground bex*ore rxpenSjigtor (1) airo^t contact of ttio ?xr..its with tUs pl?ytotoxic chosaioal spray,"(-A d-v^ictior. of the loaf ecev. tixas eliffiinating: such important function*il'phot^m-fchesls and tranapl^t-icn, and (3) exposure of the inmiature

fruits to direstt aunXijjht*

lo«r

pnta^JiJ.oxOjeneno.t :«■* boing used on both pineapple and sugaraitationsfor cor.troliia£? v^eds {on the latter at rathor^low gallonages

i-D"'1^ bv airplane ';t wa«? dscilded to test this material in a gulch having/d^fle" s^d of rather larRf.: f?w.^ trees. On May 11, 5 acros of guavawr'wFU^wa (iCatikMaah^. sV^asi-^d asy arcftieation of psntacshlorophenolv*e& K"?f3r in «n fi-tter/ot to .iefoTOate the tress and thus cause the iruatsto i-op- '^he fcrmvaa ussd wiKUtjad of 5 gallons of Gaviota General WeedF^ier*-1'"* >2^ pouadg p^tvs.chltrr,v:d^nol psr gallon) and 5-gallons -of. Union

'4D-60" aDplied by a:i.i'pUiR9 at the rate of 10 gallons (5o6 poundsa) par ^.. A fairly good courage was aohiewd, and

observations made en I%y 17 Ii: dilated that the top foliage was badly burned■>

A considerable awuat of greer. 'foliage occurred lower down on tiie trsesj,

although .f«3w guav% fruits are found on this foliagee ?i?o weeks later

practically all the top foliage >/as dry or had fallen off and the trees

thus Gpix'ied up bo that a second application could effectively reach the

foliage*

On cixie 54 it Uo.3 iK:t:i,jaft that now leaf growth was pg

end an additional, spray consisting of" 5 gallons par acre (2aS pounds o.C

j.?entach."?/jrophenol} of the saw- :^3?-ni;Llt?.tion was applied * This applicationkilled all the flush groviiib ;?::.d psnetre.t=3d the upper folia.ge., killing

irxjst of :ha leaTss :Lr the

'Oie n".nabej7 of rips iir«.ilts -1-n th-s treated and check areas should

bs the best orifcerior. for m«a^-u:".Ln{i the sf;r'ecfciYen©s-s an this treatment,

as the picvosb vu& zo pmwirl tlio .vipgning of host f5.*uits- (Fruit flies

do not o/±po?:dt in green gua;«;s J * It wis also desirable to lcnow at vihat

ci-tage '.uo«t of the f).*uit oj.*op cctjurrsdp as it is possible that such

•ircss'Jaaent ycvld be effective! c'gj.i:^s4- fruits of a given tdse but not beyond

this point* Consequently - bhe :>4j.o^"ing dsvfca wex*e collected in the

tree, talent; (Kav3eong23.ua. 5} &V3© v..bwr;k (Waipic 3) areas s. 'She ground beneath

ths canopies of thra^ iiopr3sej.-.tavi";'e trees "in the. ■treated and check areas

v&e cleared of aH grass and J:rus*ii-» Weekly'' counts were then taken of alldropped fruits in these clearid^s* Tha frxiit vjas. -screened according to

irJ.zG Mid waighecU As ripe i*?i:.i"!'/3 .appeared 'they "we:"e also counted and

weighed*. .The resul-ts ar^ s'-iov-ti in table 9-«»

As sh?.nm i& table 9;1 JJ559 fruits vreighic^ 3.004 pounds were

f?o3..1»c"lied from ths ^learligs I'eneath treas in the treated area* as

compared w:LtU 6^743 fruits vj©:ighing 1.60 «6 pounds i:a ti?.e checko In the

tvvztzd a.t'«;ia S5359 o.C the fruit;; d/ropj'Qd while still gs^esn, as eonpared

vith 3^964 gJ-1o3n fruits in tiii-; *jhscko No ripe fruits h^e "been coLlected

in the treated J2re;a;, as eoiD.p.-:-red vith 2^734 in the choek° It is apparent

that lartj© nuaibsrs o.C isTCi^ty:^ .-fr-uiLts drop np'naally, eEspecially those

miderr 1/2«.Adeh in d

-ilthcjugh <;.'.jis t-«.«t. .1 :ji? nyt been completed* it- is appoi'ent tiiat

.of a defoliarit has g^ea'^/- reduced ths :lnfost/a.ticii in the treated

iVia ;dp3 gutsryas in i..hv «^v9fi)i: ares vere heavily infested adLthand r'.c larvae havs o;:cn roficced .frori green guanas in either gulcho

The tota". aost of apflyi/ig ;3\v:h -iroafeenv «s arnprcxi^uately §5<>92 per

acr-e for.* the twa appl.icution.3j-. :Lielt.ud5ng 8->4 pounds of pentachlorophenolj,

15 gallons sclvisnfe, and Che c<.s'i of airplane application o This would be

\<Y>& most aooracr.:icsl procftdui'^ for •vl;ba5.:aat:.iig host fruits in certain

scr"j.b guava thickets on I-an^iv

■» 320 -

Table 9.—3£fect of defoliation in th© fruiting of guava» Kaukonahua GulefafWaniawa, To He, 1950.

Date

Kay 17

25

June 3.3

21

ffrerated arpa Check

Lbs

3*70*2

Ito

US

1*0 I ^007. G*7 11*155

Rips

July

1424

Total

0*5

0*5

10,4

773 I 0241 i 0

Green fruit

1"

241

Q

K.IWKKIBIUUKkV^MS.Vl

111

123

5

b42

211

15

75

Under

561156

124.

29541080

Lbs«

0.A

30?

244

Ripe

fruit

i v

/,.=8 12,383, I 62

S.4 j 641 ! 114

Over

G

0

"I?

44 |

3/4^

I 2!L0 j 12 j

S.559

34 227 1 13.0 I 250 136.1 ! 4S2 I 439 1 19 I1

13

17

95

£l

>6

l/2»- | Under

3/4»jl/2«

40

210

243187

199"?

39 I 395

14 I 241

33 i

79 I 493 633

181

tetflwan.-:

7354 jl60*6 6,756 |27S4j 126

58 f 73 | 641 J4M. |.1,2$3 J1D96 j .35 ! 56 | IS 3858 14 1 10

341 :j 3S7 3118

321

EM~.M^M&^.^MM£M, (% and Hena©rson) ««~To determinepej.rcj©iatags3o.f frmt files i';hat"W?uld reach MoPhaiX traps baited lyitlidgird fenasnted tfav^nsgar iurs, and the period of time involved, marked

fe;aala flies -^ere liberated &:■:> the Honolulu airport on March 30 and on

April ?.,. and 14, On Has-oh 3*3., 99 fl:les having' k white mark on tto« thoraxyers 'liberated, at. the airport As there -^as a ij-tnct of 30 miles per -hour.,i>h'9 flies T*ers libe-satarv ir> ;:,ha sheltered areas near the traps« Forty-m?Qn of the iiar-toed £Uos -yew recovered in the traps on April 3., and* 6as. April 6. or a total ?/&ac.m%y of 53 psraento On iipri2. 7, 90 ibdt© andyellow flies vare .I:ib©r-£,t3d aboi7.t .150. feet from 'bh© buildings at poiatsac:?thy southr .east,, ar.d V3.gt:«. l!here ws a wind of 15 milesfper hoiiro'.I'W'^.uy^-oina of these fl:Us -^ero recovered in tho liraps on April 10r and4- on Apxdl X;,5 or a totnj. of 26> percont* On Apr.il lA* 10Q whits arid -rod

fl'tag were lifceratsd at th-s af.:i;^ points- during a «ind of 12 miles per

hours. Twelve of thosa .rli.3© "ffix-e reooversd it> the-"feraps an April 17* 2

on April 20s and 1 on .%ril .25. or 15 psroent reco-raredc The'l2^a:ue wind■was from the southeast5 e:rf i?:» gsisara3.^ toward the Damon tract* On -April20., 1 wliit© and reel fly ya-3 recovered in -fih© Dajaori tract, about 1 mile-

from tb.e -point, of llfo^.tdon* If. if} of interest -Iihatj wbea Liberated

150 feet .from th© biiilclnng3, 15 to 28 percent of tbs' files were reccyej^ed

in trs.ps located aro-j&d t^3 airport bulidings? aad that 53 percent of the

£l:i3s act'ual3.y reaciiiiig snal^ered areas were recovered in th©- traps- Fi*osd.ariSLtely 16 to 20 te^-^snt of "the rocovered flies required raore ti

to resell the tre/oss*

C)n AtjpsLL 21j 3.G0 wh4te and grssn male and resale £ruit flies

w^a's JAberated in the ssiaa partitions a« on April 7 aad L4, with' a southwind, of apppccdjjiats;.y S nils:.-, per hous1* Four c^^s later9 15 of tlie.

meo:ked. Liales aid 8 ;.j.f t.- o ::4a.:r3c??d fecales- weije formd in- the traps &t the

ai:-?port* the following. cdiJL«otions- i-jers then raacieg April 2?^ 3 raeles

szid -4 females| May -4? 1 cale snc\ 1 feroai.e| Kay XI9 t lake and l'feiaaleoThmiStf 20 .percent of tue rsala.-- aad. !L4 percent of the -fezaale^ irare reoove3?e&

at the a:U^por"J Isi MeP.bsUX traps bsitad with evantilaxd1 f©m©nted»*s\2gar l

.In addition^ 4 females v;e:?» .^-aco^e^ed in traps at. .Damon-villa.ga-, about

1 Tidlfi; e^ay f:rom the aij:po:?t«

.From these data .it Ifj apparent tfc&t M6Pfa&H traps. "baited with

. Hsugar lure-::aa# b(~ ^pscted to catch only a stall percentage

of the flies ?*eaching airport or Eeritim® ports on the mainland^

if fairly ]:ig)ji winds occur at the t

322

-0—-STICKS ON LAMI (Keisor and Henderson)

the past ninel

S£^£§J8Ui^iJl&Jd^^^ the past ninemonths, studies were conducted or? the island of X*anai gathering informationnecessary Tor, and preliminary to, area control activities* These includedthe determination of population densities, location of flies, concentrationin different ecological environments, fluctuations as related to naturalclimatic conditions and presence or absence of host fruit, movement bothintra- and inter-island, incidence of infestation in typical host fruitand its relation to population fluctuations, and a general survey of theisland for lociting and delimiting the major and minor stands of the fruitfly host plants* Those studios rare still in progress- The data gatheredin tha first six months *;8v*o poresentecl in the previous two quarterlyreports <■ The data gathered in the past three months are reported herein,and an attempt will ha made to analyse and evaluate the results obtainedfor the entire period under study*

As in the two previous reports, the data from the different

trap circuits were compiled separately for comparison with previous results,

and with populations in other enviroxuasnts • Table 10 lists'the weeklytrap collections.'froia Kaena towards Lanai City* Traps 1 through 8, "located at the northwestern most point of this trap line were discontinued

at the end of Marchs 1950, as they ar© difficult "bo reach and served

their purpose* 'Ihese 8 traps (located in wasteland area similar, it isunderstood, to portions cf KeJbool&we) indicated that flies are presenton Laoai in barren areas i/:'-vh no host trees, and probably go there in the

course of exploratory flyings* Traps 9 through !?, located in trees

planted especially as windbreaks, showed moderate populations for the fi&st

few weeks, with marked deci'oases towards the end of June* In general,there was a sharp drop in populations in this ar©a««»799 flies for the

second quarter of 1950 as compared with 3,225 for the first quarter of

1950 and 1,545 for the last quarter of 1949 • Also, there was a marked

Increase in percentage of foiaales—70*6 percent for the second 'quarter

of 1950 as compared wifch 52 «8 and 32*9 for the previous two quarters,

respectively•

Table 11 lists fciio weekly trap collections from Kaumalapau

Harbor towards Lanai Gifcy* Those traps which were positioned on telephone

poles for the first six roonvJas were also discontinued, as they served

their purpose in showing that the flies are attracted to traps which

are placed in host or other shelter tre<js, and that the telephone poles

serve neither purpose during most periods* It may be readily noted from

table11 that traps 24 through 27» which are positioned in the residentialarea at Kaumalapau showed the highest populations* However, trap 37,

placed in..a windbreak tres* again showed moderate populations, indicating

tb.e Inportance of such shattered areas to the fruit fly in the course of

exploratory flyings* The Kamnalapau trap line also showed marked

population decreases and peresr-tage of female increases*-^., 572 flies and

323

Table 10 feskly trap colloctions of adult Da forsalis from Kaena towards LanaiLarai T* H«* 1950, l/

No.

9

10

11 •

12

13

1415

16

17

18

Trap

Location 2/

Eucalyptus

Shrub

Eucalyptus

Shrub

3ucalyptus

Eucalyptus

Ironuood

Ironuood

Ironuood

Tenk3/

Percent female

7

3

7

9

13998

11

6

32

69=6

Anr

14

8

11

9

4

307

2

9

42

72a

il

21

2

18

22

468

47

12

7

8

1

70.2

28

8

3

239

8

1315

17

190

62.8

5

0

0

1

1

2

0

2

41 -

0

72 o7

12

1

2

2

1

5

0

1

350

75.0

19

42

6

7

136

9

3

5

2

66.7

26

2

1

1

2

0

8

31

40

81.8

!

2

42

2

5

7

4

2

76

2

70.7

9

0

0

50

8

11

8

350

75.0

June

16

10

5

3

5

132

3

7

1

80 oO

23

I

0

2

0

9

33

2

8

0

82 ol

30

1

0

1

2

3

0

0

0

0

0

71.4

Per

trap-Say

«L

*51.0

loO

2*2

1*3

*7

♦1

3/ Fermsnted»sugar lure in KcPhail traps *2/ Tree or other object fron which trap is suspended2/ Wooden water tank

- 324-

Table ll*«-4feekly trap collections of adult D& dorsalis fron Kauraaiapau Harbor towardsLanai City, lanai, T* Ho, 1950* 2/

No.

20

22

2324

25

26

27

28

32

3436

37

43

JSSBL ^Location 2/

Eapaya

Kiawe

Kiaue

Mango

Orange

Kongo

Cherry

Goconut

Koa

Siaue

Norfolk pine

Acacia

■

Percent feinale

7

330

7

3697

31

638

2

1

4

59.2

April

14

630

4111

88

77

348

1

418

64Z

62,3

21

18

0

2

836

6419

2

0

2

11

70

6.1 oA

28

60

1

2

366

68

298

59

9

13

47

76

o3»0

5

731

1

3641441049

47

2

2

651

64.0

Max

12 19

0

1

192

25

89190

3

0

I

18

62.

0

1

75

11

77

27

3

6

1

2

42

3

>I 59 .=3

!

26

2

0

1

OS

32

76

532

3

1

41

64.O

2

0

0

4411

70

532

3

3

1

7

57.9

I

9

3

3

2

45

23

70

30

1

1

2

0

5

72*9

Jimo

16

0

1

D

27363828i

30

0

3

3

68*6

23

2

1

1

22

17

49

190

1

1

0

0

1

66.?

30

0

0

1

7

28

13

91

0

Z

i

' 5

1 1

1

61.8

For

trap-day

248

al

•3

15 *S

6*5

11=6

*> •*•

4*4

1/ Femented»sugar lure in MePhail traps-g/ Tree from which trap is suspandled*

6.2 c9 percent female in the second quarter of 1950 ae compared with 15*815and L%«2 percent for the first quarter of 1950 arid 18,801 and 4.7*8 percentfor the last quarter of 19.49 <>

Table 12 j.isr,s the uae<3dy trap collections from Ilonele Beachtowards Lanai City* 1% nay bo -readily rioted that populations were very

lev* especially for tJrio lest *raeks in Jime» However, it is of interestthat, (as w3Xl be shown .\ater,), although populations were comparativelylow ell over the inland clrring this quarter9 there -were still exploratoryflyir-gs as no^ed by the <jatchf».-3 in traps 49 through 60 which are located

in fciawa tree?? alon*; o:c near too shore line at Ifenele Beach and mllssfron host trees* Populations for the Manele trap line were 1,0^6 with

68*1 percent female in tUo second quarter of 1950,, as compared with 9,881and 57»6 percent for the first quarter of 1950 and 1,192 and 5O«5 parcer.ti'j fox- tho last .juar^or of 194.9•

Table 13 lists the weekly traps collected froaa Halepalaoa landing

towards Lanai City* Theoe trap;-, are positioned In kiawe trees located

in ar- almost noRplet«Jly hosfc-fei© area*. In general, those traps away from

the Oiract shore lins and sheltered from the wind showed higher populations*

Traps-. 137 through 145, which a:ns along the road leading upward from

Keomoku tcwartls Lan&i 01 .y aro escposed to strong winds and showed

practically no populations during this quarter. It is of interest that

trap 125j> which yielded 2.-jj ararage of 22*8 flies par trap day, showed

tiie highest concentrations in V.&.& area during this quarter, and also

duxlr.g the first quarter of 1950 (54*2 x>er trap day). The orO^r explanationthat may be offered -at tho present time is that this trap is positioned

in a coconut grove c? approKina"":-ely 100 trees with nost of those in bloom

for the past feu mon-^biij. an:l tb.at the fruit flies are attracted to the

odor of the trsas &r>d/o? flows?:*r» and/or fruit* Populations in this traphavs been so ri3j*kodj;r h.1,;;h3ij Man tiia others in tiii» host-free areas that

seme odoriferoLis sur^ttmoe sKn:'.a?.ited b;/ the trees nuist attract tlie

to tl:is conceittration cd eosonut's in the cou2*se of exploratory

There v.ere 3sk39 fl.i«-as caught :U\ ths lialepalaoa trap line iii the acoond

qus.rtei* of 19^0 wtifo 6oo^ pgrnont fervilea, as coiopared witli 11960S .(:oid

54eS porcent :..n the ^'irs'i. quarvi^r of .1950, and 12.,431 flies and 50«2 percent

in the last quarter of X^£-3«

The •iieeld,:/ trap records for Lanai City are listed in table *3-4oCity qX&o s}iovvs.3d drastic natural population reductions during this

quarter, and mxked.. .increi&s3£ irs the percentages of fenales« There ver<&

16,704. flias 1-ra.ppsd In v.cnai C:.ty wiub an average female percent of

61«S;. that could be •ii:?-ec:f,Xy ooinpared with 3^>0,0Sl (4608 percent female)

for the first quarter of 1150 and 1331301 (49o3 porcent ferrate) for thelast quarter c>f 19A9» Or- fc.ae average, thoso traps which tiers located in

arsas snelterad fror:.. the vilad and diract sunli^ity and/or close to or

positioned on citrus- tre<-.:s afc-oucd. the highest populations^ Trap 92 gshowad

comparatively loir pc-pujUi:i:.ions - It is exposed to the wind and the avocado

■tres-3 leaves ars too liigh t'j protect it* Trap 95s viilch yielded soany flios,

is on an oran£© tree adT5-.a3.at '>o another orango t?:Bo with fruit» Thrc-2

.avocado trees and a i^rovq) 01 iLiusna t:?ees are nearby* Trap 9U§ on axi

also showed higr. pop'.Llations^ This is adjacent to a group of

- 326

l2»-4feeKLy trap collections of adult. D. dorsalia from Manele towards Lanai City.

No.

4.950

51

52 •

53

54

5556

5753

5960

61

62

63646566

6768

6973

74

Trap

Location 2/

Kiawe

Kiawe

Kiav/e

Kia^e

Kiawe

Kiawe

Kisruje

KiavQ

Kiave

Kiawe

Kiave

Kiave

Kiswe.

Kiava

i Kiawe

Kiawe

Kia\*e

Eiawe

Tank y

Percsent- fejaale

7

9

5

5

2

6

4"9

2

9

310

*>

0

i 15

; 2

G

0

1

6

42

69.:

Lanai* -

A^il

U

1421

4• 6

5

1432

4

511

43

40

2

0

1

9'0

13

3

9

5

L 71*6

21

2

1

52

32

2

1

1

0

1

9

ii

0

2

2

7

49

1

0

1

.J?;,,,

1950,

28

16

S

9

5

142

7

2

0

5

1

10

1

0

0

1

1 .

1

1

9

30

1

6

72cB

1/

5

2

516

131611

16'&

2

6

19

I o' 0! ...

1

0

0

0

0

5

5

2

1

59-2

•

12

0

30

1

3

3

11

20

2

4

39

10

0

0

0

0

0

0

40

0

o

66.7

19

6

U10

3

5

58

35

42

7

10

40

0

0

0

0

0 .

41

3

0

2

61.0

126 j

5

40

2

12

5

15

147

2

2

6"...

0

02

0

31

0

i

0

0

,. 3 ,.

63=5

2

0

■ 2

41

2

7

11

231

0

2

51—

1 0

i 00

0

1

0

2

31

0

| 68 o?

9

0

1

0

2

6

16

0

2

10

1

0

I

0

0

0

0

1

1

30

1

June

16

0

0

1

0

9

■4416 -

30

0

2

0

0

i

0

0

0 •

1

1

0

0

0

0

78.6

23

0

0

0

0

2

30

50.

1

1

a

0

n

u

o ■

0

0

0'0

0

0

0

2

73.6

30

0

0

0

0

0

1

1

2

0

0

0

0

0

X

G

0

0

0

0

0

0

0

0

0

60*0

Per

.6

•7"5

•4

*S

«9

1.7

•4•3-4

,-,

rO2

K1

*1

-•2

...

«2

*1

i

1/ Fermented-sugar lure in Mcfljail traps*2/ Tree or other object from which trap .is suspended*

2/ Wooden water tank*

327

Table I3»«~*teekly trap collections of adult Dp doraalis from Halepalaoa Landingtowards Lanai City* Lanai* ?* H*, 1950« 3/

122

123124125

126

127

128

129130

131132

133

134135

136

137

13&

13914a

144

Trap

Location 2/

Kiawe

Kiawe

Kiatie

Kiawo

Kiava

Kiave

Kiave

Kism

Kiawe

Kiaws

Kiawe

Kiawe

Kiais®

Kiavje

Kiawe

Kiawe

Kiawe

Kiawe

Kiaws'

Ironvood

Bareent female

7

31U

3

23

1440

18

30

1

7

4

10

5

147

2

U

0

1

1

32

69«6

Auril

14

17

6

12

646

511

2

61

26

1

2

12

993.1

60

31

4

59.0

21

«

92

4

7

2

37

17

2

3

41

32

3

5

41

2

75.7

28

—

0

0

1

0

1

2

2

0

1

3

9

2

0

0

1

0

2

66,7

»

«-

0

0

0

1

0

a

0

0

239

28

0

0

0

0

0

1

71*4

MaM

12

4.5

3

2170

0

0

0

0

6

1

0

2918

60

0

0

0

0

0

67«5

19

30

5

168

6

2

1

1

0

50

0

19

9

30

0

0

0

1

2

78.7

26

437

92

5

2

0

0

2

40

2

7

38.

0

0

0

0

1

0

70,7

1

2

96

12

117

2

0

6

1

3

3

4-

5

13

7

1

0

0

0

0

1

0

76*8

9

2

2

7

80

1

0

30

0

1

2

0

4

3

1

0

0

00

1

0

76.6

Jim©

16

11

2

2

103

2

0

0

1

2

1

0

0

1

2

0

0

0

0

0

0

7606

23

1

5

3

621

0

0

1

0

0

1

0

1

0

1

0

0

0

0

0

1

77.9

30

3

6

11

80

0

1

0

0

0

I

0

2

1

0

0

0

0

0

0

0

69*5

! ' Per

7

Icl

%

*5%

»9

»3

lo^•*-=•-?

^*3^.8.2

%©Jit

1/ Fermented-sugar lure in McPhail traps2/. Tree from which trap is suspendedo

328

No©

76

77

78

7980

81

82

^3848586

8738

8990

91

92

93949596

97

98

99100

101

102

103

104

105106

107108

109

110

111

112

Perce

Location g/

Avocado

Banana

Avocado

7

49

9

13Mountain apple 17

Avocado

Avocado

Citrus

Avocado

Avocado

Fig

Cedar

Orange

&Qquat

Avocado

Mango

Cactus

Avocado

Lemon

Avocado

Orange

^lderbQiryMango

Avocado

Avocado

Mango

Avocado

Norfolk pine

Shed J/

Avocado

Cedar

Norfolk pine

iforfold pine

Avocado

Lesion

Avocado

Shed

Jit £gTH2l1.Q

919

1391

79

Z2

a199

6442

4481

11

67L38

246

147

X9

Z5

52

1

%

22

22

2726

5

14

36

SB

73

6

14

26^

18

57

62

170

15

32

84306

112

59

240

24

2473

3321

55106

101

3B31*50

43

53256

27

118

334116

18

4

241

1521

10

3

57*1

■Ml

21

54

39

20

?418

26

35

181

696676

10

29

9412

18

20

382

126

78•a

A?

. 96

37

8

2428

3317

312

56

5953

99

8

28

16330

16

176

42

434a

18580

121

183

72

82

15366

5

51

209

167127

4

3470

80

56

61

25

103

3126

4

70

8

7451

15

5

69

418

118

78

97

12360

124

59

17466

26

36

130

53

19

32

90

932io

466

52

5&

10311

7

90

22

22

1

7

12

79

71

12

j

12

36

13

74838

21

30

89

4228

67

1412

122

13

7

16

52

6?

20

21

21

27

6

31

23

5

1

34

14

25

29

5

19

3460

16

6720

14

19

29

112

72

90

6528

31118

34

1530

8442

73

17a*

is4329

6

25

42

16

2

a

36

3410

2

26

%

1

8

39

43

11

5930

63476742

16

28

124

29

7

21

2?

3528

14

10

2410

235

21

9

9

2

6

66

27

24

2

2

33

5

9

32

23

7

32

IS

7430

58

29

6

7

90

30

11

64

17

27

8

46

15

336

28

46

30

3

5

2

10

16

9

f

9

2E> '

35

15

40

2318

3

11

96

53

9560

4

17

126

21

8

15

4420

22

197

29

18

28

111

2

36

5

3

26

1216

6

6

June

16

22

5

5

47

313

3618

58

30

33

49

4

3

32

9

3•^3

30

2L

200

15

3

2

28

2

2

10

2

2

14

48

3

7

2

23

8

2

20

20

5

63

932

21

7

12

6

72

14■■•■ v

10

20

40

'A

4615.

16

4my-

21

0

165•

1

6

60

6

20

2

30

7

5

5s

49

3

11

42

17

11

11

1323

3

3

2

15

L

?i i7

262

2

1

21

1

1

2

6

52

15

1

—.—^.g,..,^...f...

2II2*0

9*2

2-9

5*115 06

J-i? 6 i

3*71? 6

i 5«0? .

13 »6

10.7

7.3

6*2 '

4«>2•■{-•»«•

1*5

*55e7

4*2

5o5

<—..—zJL^

|/ Fennsnted-sugar Iih-g in McFh&il traps*. 2/ TreQ or other object from which trap is suspended.

citrus trees with green £'ruits and another avocado and mango• A goodexample of the importance of shelter is trap 112* unioh is placed on ttesida of a shed* This is completely exposed to the winds, and allowed thelowest populations* While Lanai City xaay be considered a sheltered areaas a whole, the flies are evidently more attracted to those oortion3 whichare more sheltered than others»

It is not understood at poresent -why citrus attracts the fliesin Lanai City* An incidental study was made in which citrus leaves inMcfhail traps were placed on avocado and guava trees, avocado leaves oncitrus and shower, papaya fruit on guava and citrus* banana flowers oncitrus and avocado, 'and banana fruit on avocado (all in McFhail trapsas citrus leaves above)* Only the banana fruit (ripe) attracted flieswhen observed 24 hours later» (The results noted with papayn are inaccordance with those observed e.t Lahaina, Maui*fcgr Lanai personnel, whenno flies were attracted to sliced papaya fruit in MoPhail traps on trees,whil© moderate numbers were around sliced banana positioned in a sinilarmanner*) However, as noted above, there are strong indications in kanaiCity of citrus being an attractant to the fly* While it is purelyhypothetical, this may, in a senso, be interpreted as meaning that thefruit fly may be very damaging to citrus treos on the mainland, hotid.th~standing light infestation noted on Lanai at the present tim©« Since3OB0 flies do complete their life cycle (as noted by rearing data), astrain oi' flies adjusted to citrus fruit may develop on the mainlandfrom those having the necessary generic constitution»

Trap 110, on. a lemon, tree, showed low populations* This trapis exposed to the triad* Trap 90^ on a mango„ had high populations«»This is positioned in the only sheltered area in the ixaoedlate vicinity*.Trap 07S with high populations* .is on a citrus, and there is anothercitrus tree adjacent. Trap 77, on a banana and surrounded by otherbanana trees showed low populations * It is located in a windy area*Trap 96> on an elderberry tree in blooa (end of June., 1950) showed, veryhigh populations«

It is of interest that of the eight traps with the highestpopulations in Lanai City ii\ the second quarter of 1950, six (traps 87,84., 90s 95, 96, and 94.) warfc also among the highest traps in the lastquarter of 1949* (Trap S3 vms among the eight highest in the last quarterof 1949 and the first, quarter of 1950*) Of the eight traps with lowestpopulations in the second qriarter of 195Op three (traps JL129 103 anci 77)were also among the eight lowest in the first quarter of 1950 and two

(traps 112 and 103) were among the eight lowest in the last quarter of194-9 • (Trapa 1D1, 108 and 91 wer© among the eight lowest in the lastquarter of 1949 and the first quarter of 1950*) Evidently a positionfor a trap is comrarativeiy favorable or'unfavorable regardless of

population fluctuations* These data, may be of'value (along with others)for pre-treatment Jevols, and be considered "drastic1- tests for population

reductions * (Traps 125 of the Hfaopalaoa run and trap 37 of the Kavanalapaunm which \&re also consistently liigh, may b© included in this )

» 330 ~

The weekly trap collections for Knob Mil are. listed in table .15

This trap line also showed va&rked population decreases and percentage of

females increases-"^* 91-6 fliea and 60^8 percent female in the second

quarter of 1950 as coiapa..?ed with 30,221 flies and 45°2 percent for the

first quarter of 1950, arid 30 .,164 flies and 48 «9 percent female for -thelast quarter of 1949°

Table 16 lists the -tfa&Scly trap collections from the Koele Ranch

residences* Again & market population decrease and -percentage of .female

increase-was not©d«««4.>??;\-3 flr.ss and 6,1*4 percent female .in. the secondquarter of 1950 as comp^sd mth 16.290 and 49*5 percent in tlie. first

quarter of 1920., and ;?.,£.$ and 53=6 percent in the last quarter of 1949*

As Hill be discussed Xa.hiizt :■..« is very easy to explain the low populations

in- the second 'quarter of 11950* However., it is equally difficult to

explain the low jjopiLkv&ioDg: at Koele in the last quarter of 1949* The

Kaerjg populations iwere ^.^0 higher in tha sscond quarter of 1950 while

the J&unalapau totals -jer.'B lewer* {'larked flies released in Kapano Gulchvena recovered at Kaufii.il,u:hv.Uv. but none ware recovered in that area which

y&re released £a Buraa boacU)

Table 17 lis'i-s the weekly trap collections for Benches 1 and 2 c-

There vrnre 2S326 flies aid 57*9 percent female fo:r Bench 1 Iti the second

q"oari;er of .1950, as coiap-ir^d tdth 9.^230 flies and 52-«0 percent fenale for

the first tiuartsr of -195:5:V ®j:d 1,094 flSas aiid 51»'3 percent female for

the Last quart-er of 1949 > For Bench 2<t there were 5?6 flios and 64«2percent female for thes H5ccr:c. quarter of 1950s as compared with 3*926

flies aad 53=0 percant r.^tolc for the first quarter of 195O2 and 398

flies and 54«$ percant .r--.?ni?.ls for the last quarter of 1949°

IS listt \la swmmxy trap collections for those traps

and fox' those arsas yhrici ctq d5»rectly comparable with the data of the

previous two quarte;-*B,-. there iibtq. 36p?33 flies in ths second quarter

of 1950 tha.l v^sy b© corny^-e:! \dfth 240^277 for the first quarter of 1950,and 2033074 fox the la;;:i; c;\:^:3t3r of 1949« Siis indicates a poijulation

decrease of S4«3 peri^nl .ix=. tne second quarter of 1950 as coaapared with

the jl'irst quarter cx; -ohs c-iva^ year*

It is oX' irr;;eir.r.t t!oat the average percentage increase inpotralat-ions ir.. lexiuJ. C:if./ j'.ul.- Knob JIUJ. vas minor, -fropi tlie last quarter

cdv 1949 'fco the firfit cr.:!^: -o;rv of 19.50-> However, there was a 'marked .average

pST^ent increo=s3^ d;;r:'^:;f;: ivhai; period iri tha Kaene_. Iknale^ Koele, Bench 1

and Bench 2 areas.> and s, nilr-ir dacrease in Kaumalapauo Evidently, \-fnen

tbero ari2 ^viarvy flier on thn .sland, the average populations in the residential

areas appear to rea&in f.;J r.1!;;' constant«

a 4 d'uy,;:-* I'lisi population fluctuations on Xanei since the

cosan<incaas»nt of otudrbis \:<:i O-.itiioerj, 1949,* for the 125 traps of all areas

Viiaicii are subject "feo -dir =fcwi:- •.;c,mpxrison« Sie continuous and shsorp drop

in population bagiri'-'bi^ i:i Lite Fe-b.rua.iy, 1950,,. aay readily he noted• la

■the previous q'aarterll;/ r-?\;^r::? the average laascirnwrn and m-inimuHi temperatures

for vhe island ox L-:wus.S wi.=:r© preserrfcsd graphically-9 and it was -noted that

the-3'o te-aperature ■■va.?:L.3.titi«ii.f.i wers in no nay correlated with population

331

Table 15 o««Weekly trap collections of adult D. doj?salis at Knob Hill* Lanais ToHc5 1950

No*

113114

115116

117

118

119120

121

Trau

Location

Coconut

Coconut

Lemon

Guava

Norfolk

Papaya

Olive

Avocado

Norfolk

Percent female

a/

pine

pine,,

7

7

107

30

6

3510

72

175

A3

53 «2

April

14

136

142

3

3

63220

116

204

58.2

21

1

14

695

8

10

88

78

64

62 oO

28

1

9

123

41

21

5160

—

66.3

5

0

6

82

i0

916

50

2

59»O

12

0

3

741

1

8

19

39

3

62.8

r

19

0

10

125

32

1423

441

7106

26

0

1

75

1

0

25

8

45

2

61*8

2

1

3

13 •0

1

12

11

30

5

68,4

9

0

420

3

320

20

•30

• 6

57*5

16

0

6

432

1

8

7

20

2

68«5

23

0

2

90

1

3

5

2

1 ■

69*6

30

0

2

2

0

0

2

415

1

61*5

Bar

.3-1*98*9

*3t>6

2*3

6*0

7*7

4»4

1/ Fenaentsd-sugar Itire in MeHaaSJL trapse

g/ Tree, from -which, trap is sus.pended«

2/ Formerly on lemon tree*

-332

Table l6.—J.Jeekly trap collections of adult D.

Lanai, T. H., 1950. 1/dorsalis at Koele Ranch residence3<.

Trat)

No.

148

149

150

151

152

Location 2/

Banyan

Mango

Orange

Coconut

Norfolk pine

Percent female

7

L06

329

L60

356

5

56.8

Aoril

14

114

236

196

320

10

56,6

21

22

130

79

88

6

5V.S

28

61

189

99

78

3

63.2

5

33

255

160

107

4

68,7

May

12

18

46

37

40

2

55.2

19

67

74

ao

117

4

70.5

26

39

94

32

54

3

6O.3

2

28

64

73

36

3

63.6

9

40

27

78

38

0

64-5

June

16

15

12

95

12

0

68.7

23

24

9

46

12

0

6V.2

30

5

7

13

5

0

73.3

Per

trap-day

6.3

16.2

13.2

13.9

.5

1/ Fer^ented-sugar lure in HcFhail traps

2/ Tree from yhich trap is suspended*

- 333 -

Table 17*~Weekly trap collections of adult Do dorsalis on benches and ridges southeast

of Lanaihale Mountain* Lanai, T»Ho, 1950 o j/

TraD

No.

153154155

156

157158

339

Beree

160 1161

162

163164165166

Location 2/

Guava

Guava

Guava

Eucalyptus

Guava

Guava

Guava

nt female

Guava

Eucalyptus

Eucalyptus

Guava

Guava

Koa

Guava

Percent female

7

10

9

82

83101

8

9

53.6

2

1

2

526

35

5

63«2

Atsril

14

13437

191

47

22

8

56.5

2

0

1

5

517

2

75.0

21

7

2

6492

22

7

26

45.0

9

30

5

5

11

4

59.5

28

7

1

91

6917

2

38

55.6

28

0

0

2

411

2

68.1

5

2

1

21

207

11

15

_52

May

12

Bench 1

6

2

62

16518

595

60.8 55.2

13

3

51

36

_2.

76.

Bench 2

16

0

0

3

2

91

5 77.4

19

9

315

211

6

7

127

71.4

92

0

0

2

5

10

3

71.4

26

1

0

2

49

42

41

57.6

20

0

0

0

0

5

2

51.9

2

40

10

15

1

2

10

64«3

30

1

2

1

0

5

0

69.2

9

2

0

2

20

2

1

10

48.6

230

1

6

0

41

71.4

June

16

40

1

11

1

38

60.7

512

1

0

0

1

0

3B.2

23

0

0

0

6

1

0

1 „

50.0

16

1

0

0

0

2

1

60.0

30

2

0

0

1

0

0

0

100.0

290

0

0

0

0

2

48.4

For

trap-day

.7

.2

4.312.3

2.5.8

4.7

3.6

.1

.1

•3

.5

1.3.3

2/ Fermented~sugar luro in McPbail traps©

Tree from which trap is suspended*

334 -

Table 18*-—Voexly trap collections of adult £«, dorsalis in nine different locations on

Lanai, T« Ho, 1950. 1/

Location

Kaena

Kaumalapau

Manele

Lanai City

Knob Hill

Halepalaoa

Roele

Bench 1

Bench 2

Total

Percent

female

7

161

28997

1742

478

573

956

302

76

4674

Aoril

14

86

524

1942781

757

869876

322

32

6441

4 58.

21

171

279

641763336138

325

220

37

3383

4 59«

28

115

9641032366

333150

435

225

47

4738

4 6^.2

11

777

138

2030

166

197

559

309

34

^221

64.0

May

12

20

424

64981

148

289

143353

31

2453

3 62*

19

57

321

120

1258

222

225342

378

112

3035

26

22

283 -85

863157

140

272

99

27

1948

0 62 08

2

41197

67668

75

190

209

42

39

1528

64*

«

40

.192

53870

106

107

18337

35

1623

4 65

June

9 16

40

140

42

541

8912&

13428

55

1197

•3 6406

28

114

14

41323

77

91

8

20

788

67

3 30

7

68

5

428

26

106

30

3

31

704

•9 65*2

Total

799

4,572

1,046

16,7042,918

3,239

4,5552,326

576

36,733

1/ Fermented-sugar lure in McPhail traps*

335

35000 .8;

30000

25000

OctoberTll 18

Kovo;iiber

FIGo 4 - Weekly trap collections of adult D. dorgalig

for Lan&i, and weekly maximum and minimum

temperatures for Lanai City« Lanai, T, H«f

1949-1950

Number of fruit fliea

December Jer.uiarv

i6 17 24~3i6 IfFsbruarv March l.pril

5 1S~19 26 2 9 16 23 30May Jiiue

fluctuations« Included in iigure 4 are the absolute maximum and ninii.ium

temperatures in Lanai City for the entire study period* It may also be

readily noted that these are not correlated with population fluctuations°

From October 14> 1949 through June 30, 1950, maximum temperatures in Lanai

City ranged from 73 to 82 degrees Fahrenheit, and minimum temperatures

from 54 to 64 degrees*

Figure 5 repeats the population curve presented in figure U9

but included the average -weekly wind velocity for the entire period under

study© Mention was made in the quarterly report covering January-41arch,

1950 that the degree and intensity of wind velocity apparently affected

fly catches, since, as noted toward the end of 2-Iarch, populations vrere

going down markedly and wind velocity was increasing in a similar degreeo

However, we now know the cause of the population decline (end of guavaseason)» Also, the wind velocity decreased in the second quarter of

1950 but populations were still on the downgrade* Nevertheless, as noted

for specific traps in Lanai City, flies are not as active in windy areas

as in norc sheltered ones, and, in pineapple fields, they are definitely

less active in periods of high wind as noted by catches in the McPhail

traps«

Figure 5 also includes the period when ripe guava was collected

for rearing in Kapano Gulch and Burma ftoado The Kapano Gulch guava area

was studied from the beginning of its guava season in October, and the

first ripe fruit was gathered about October 20, 1950• (The rearing da£a

from Kapano Gulch is valuable for protreatment infestation figures»)The guava in the Burma Road area was not found until later, and ripe fruit

vast gathered from the ground every week until none was observed* It may

be readily noted from figure 5 that popuiiions commenced decreasing

towards the end of the guava season in the Burma Road area* (The dotted

line extending backward in tine for the Burma Itoad period signifies the

presence of guava, since observations were first made towards the end

of the guava season in that area*)

In the previous quarterly report, an attempt was made to

explain the population fluctuations on Lanai* It was shown that average

weekly maximum and minimum temperatures, and average weekly rainfall

apparently were not factorso It was believed that average weekly wind

velocity may be a factor since there was an inverse correlation between

populations and wind velocity towards the end of March, as discussed

above, and population fluctuations in pineapple fields were definitely

associated with windy or relatively calm periods■» It is now known,

as noted from figure 5, that over-all population changes are decidedly

correlated with the presence or absence of ripe guava* Nevertheless,

minor fluctuations within the major ones are probably associated with

climatic conditions affecting the activity of the fly, as shown by

catches in McPhail traps«

In the course of collecting and counting the Oriental fruit

flies in the McPhail traps, records were also kept of the numbers of

the melon flios* Figure 6 shows the population fluctuations for both

species in i-^iunalei Gulch« It may be noted readily that there is a

337

35000

30Q00

25000.

2000^

15000

10000

5000

FIG* 5o - Weekly trap collections of edult D_. gt

average wseklywind velocity, and period of

ripe guava* I/anai, T. H«, 1949-1950«

Legendi-.

number of fruit flies■■

Wind velocity

' ■ -

!i-?X 23 L 11 1-8 25 2 9 16 23 j& "bHt^S^-^t^TW^TiSTil^^i^U^October Korembsr December January February March April

5 12 19 26 a 9 16 23 30May

or6T?0T£.>.T0T&c

000X

jo

GOOS

g--°HOS

E

0009

0002

339

direct correlation between the fluctuations in number's of these two species.,

even if on different levels* This may be observed also in Lan&i City

(rig-. ?}, and Knob Hill (fig* S)« .Sjjioe the food of these Tiles is different

(nc melon flies were roared from guava which caused the Oriental flypopulations) and as the season of gardens very probably does not coincidewith the ripe guava periods ths similar flucini&.t&aa must have hsen due

to climatic conditions« Of course when melon fly food Is very abundant

(middle of May through end of ■Tune at Kaiamalapau«»iTig- 9)s this relationshipwould not hold trus« However^ oven at Kautaalapau, the similarity was

noted at least in the first half of the period observed*

Figure 10 shows the population curve sines the beginning of

studies in October, 1949* and the percentage of female flies* in the

last quarter of 19,4-9 and fehe first quarter of 1950* it was noted that

there was an inverse correlation between population fluctuations and

percentage of female files*. However,, this was for the entire island*

acd. as the highest populations were found in the residential areas (Lanai

Gity, Knob Hill, KosXe 9 and Kattmalapau) a breakdown was made into differentcategories* This showed that the inverse relationship held for the

residential areas (with fruit trees), but there -was a direct correlationbetween population fluctuations and percentages of females in so-called

exploratory areas as Kaene$ Halepalaoa^ Manele and the guava ara&s under

stvjdy* As noted froir. figure 10, the inverse relationship does sot

hoiJd after the end of March, when populations declined below levels noted

sirj.ee these studies were begun* Wni.1© the percentage of females had.

increased, the fluctuations were not inverse with population trends, as

.notad in the previous two quarters*

Figure 11 shows the population fluctuations and percentages

of females in X*anai City for this quarter* It will be noted that the

inverse correlation^ so evident for the last two quarters^ is not

present during this period when populations were extremely lowo 3n

factj during soir-.o weeks, there i;as a direct correlation« It is also of

interest that the percentages of females were above 50 during the entire

period for the first tine since these studies were eomenoed* Evidently

the taales die first-

■ Figure 12 shows the population fluctuations and percentages

of females in MaunaXei Gulch for this quarter* Here too$ the inverse

correlation noted previously is not evident during this period of Low

populations* iilsOj the average percentage or f©nal@s$ as in Lanai Gity$

is above 50 for the first time r=inc© studies were made in this area*

Figure 13 shows the population fluctuations and. percentages of

females for the Manel© trap line during this quarter■* For the two

quarters previous- thsre was a direct correlation between population

fluctuation's and percentages of famaleso However9 during this quarter,

the relationship is inverse during some of the waeksa This cannot be

explained at the present t£:ae«

6

■

■

L&■:■■■:QIftOT_£

pus

jo

■

.;:©05(1

ooov

0008

*

1

1

s'■-f

■

0C09T'

m

o

3

■■'■■

/^ess--;

717"

1000

\

341

no, ti* - Weekly trap collectioas of ad»It hs

4

kegfcm

" .

16° 23 30 6 13 27 3 10 17 2^ 3 iO 3.7 2431 7 U_21T... .... pAVt«m«1*iv " ~ -

5 12 1$ i6 ■■r -

,i-J

■..1

r■

^-

:2

.■■■

:<...;

as..

,/■

-■■

-■■■■

Number

.Dof

KCacus

^aprgali

oQ

•..

:

;>;

■■■■o

.

..,

■■

s CT 1

'■:> ir'go

HI

\C

r-5

is

K°

If-

1

O

,■.-..

■

3500 ,,. ....

344

FIG, 11 = - Weekly trap collections of adult jD. dorsal!s and percentage of female

flies. Lanai Citys Lanai, To H.P 1950*

3000 ;.

2500 ..-.■■

2000 V1-*

o

150c

&

pi

p

11

1000 &*5

Legends

-.. v - Huaber of fruit flies

Percentage of female flies

500 I

■

'"" "•TV

■o ? i 1

*'SS" ..-.

Met

——i^——--23- —~3Q~ ■

5250 8£— ,-

- 34-5-■

FIG. 12, - Weekly trap collections of adult D. dgrgaUjc and percentage of female flies*

Maunalei Gulch^ Lanai; T* B.^ I95G*

4500

750

■

.-.,.. - , . ■ -.-..- . .■..-■..

ibar of frait flleg

-,

•

■ ■ ■ ■ ■ ,

V UA n

21

i I

12 19 "26" 30

350 .

■

300 ...

■

250 :

200 .

100 81

- 346

Fig. 13. - Weekly trap collections of adult 3D. dorsalls and percentage of female

flies • iManels trap line? L-snel, X. H«, 1950 „• *.

Legends

Member of fruit flies■

<

L

p

t

ft '• *■*

'

Figure 14. shows the population fluctuations and percentages

of females for the traps in Kapano Gulch« The results hare are also not

in accordance uith those of the previous two quarters. There is aninverse correlation for the first few weeks and a direct correlation

while in previous observations there was a direct correlation for theentire period. This, too, cannot be explained at the present tine.

Table 19 lists the weekly trap collections-in Kapano Gulch.There were 1,4-00 flies and 57=9 percent feraale as compared with 10,2S4flies and 53*2 percent female in the first quarter of*1950. (The collectionsduring the last quarter of 194-9 are not subject to comparison*) It willbe noted that there was a marked drop in populations during this quarter*

Table 20 lists the weekly trap collections in Maunalei Gulch*

There were 12,917 flies and 59»9 percent female as corapared with 34,094flies and 47«5 percent female in the first quarter of 1950. This maybe considered jgriCB £&cie evidence that the flies move into this seeminglyisolated location with fruit trees (bananas, papayas, etc-) as the

populations varied with those of the island ao a whole. Also, marked

flies released at Xawaalapau, Halepalaoa and Burma Road were later recoveredin Maunalei Gulch*

Table 21 lists the weekly trap collections in Palawai and MikiBaains* These traps were positioned among the pineapple plants <■ There

wore 13 flies (average of ,03 per trap day) and ?6»9 percent female ascompared with 195 flies and 49«2 percent female during the first quarter

of 1950« Populations have gone down markedly in the pineapple fields,

along with the other areas on Lanai* Evidently the presence or absence

of ripe guova affects populations all over the island. Since tine guavais relatively concentrated, the effectiveness of treatment in this area

should bo aanifested all over the island- (Of course, this is assuming

that reinfestation from Maul is not a major factor.)

Table 22 lists the weekly trap collections in two pineapple

fieldso As in the second quarter of 1950, there were higher populations

in lesa-tfindy field 5508* Thare wore 29 flies and 89*6 percent

female in field 55OS5 as compared with 20 flies and S0»0 percent f§ga£g

in field 5524* Direct comparisons arc not possible with the results in

in the first quarter of 1950, a3 these trap lines were not set up until

February However, there was an average of O05 fly per trap <jay in

field 5524 as compared with »9 in the first quarter of 1,950","'and «07 fly

per trap day in field 5503 as compared with 1.2 in .the first quarter of1950« It is of interest to noto the erbremely l^w populations in the

pineapple fields, when populations are comparatively low over the entireisland. Fields 5508 and 5524 had ripe pinea£pie for the p^t few months*

There was a very high psreenta^e of feraal^g Of the few flies trappedo

Table 23 lists the weakly tra^ collections in field 5502.(These traps were set out originally fbr testing the effectiveness-ofparathion as a space apray uiien ap^&d a. a dust ty airplane in pineapplefields*) There was an average o/ onl.y O09 fly per trap day* As in theother traps in pineaj)^? f^elSz no flies were .^ecoverad during aany veeks.

2*0

- 34$■ . -

FIG. 14..- Weekly trap collections of adult p.. dorsalia sad

percentage of female flies, Kapeno Gulch, L&aai,

1950,

fl,

ZOO

o-—. ■ - ■

1

. _ . ..... L . ......

Number of fruit flies

■

- 349-

Table 19*—Weekly trap collections of adult Do dorsalls in Kapano Gulch* Lanai, T*H*, 1950« 1/

Trap number 2/

169

170

171

172

173

174

175

176

Percent female

7

2

0

0

2

16

89

51

68

52o2

April

14

1

5

10

1

15

62

a

19

57-1

21

5

9

6

1

42

77

49

32

45.7

28

0

0

2

2

15

94

12

53

63.5

5

-

4

11

1

21

70

17

56

63.9

May

12

4

4

6

0

6

29

19

7

50.7

19

0

2

0

2

38

47

34

23

68*2

26

„

0

2

0

8 .

38

16

8

69.4

2

10

5

0

0

3

18

4

7

6lo7

9

9

0

0

0

4

19

5

2

59.0

June

16

0

0

0

0

3

29

2

4

52*6

23

0

0

0

0

5

5

0

4

71.4

30

0

0

0

0

2

1

0

0

66*7

Per

trap-

dav

•3

•3

•4

.1

2*0

6*4

2o7

3»2

1/ Fermonted-sugar lure in McPhail traps©2/ All traps In guava trees»

No.

195

196

197

198

199

200

350

Table 200—Weekly trap collections of adult D, dorsalis in Maunalei Gulch*Lanai, To H*, 195O» 1/ ~

Location g/

Bate

Papaya

Papaya

Papaya

Kukui

64 358 102 60

258 656 217 135

369 612 138 94

190 1088 396 166

350 794 334 320

417 699 312 95

65.0 63.5 75*6 64«1 76.8 65o7 69o2 68.7 64.6

1/ Fermented-sugar lu-e in McPhail traps*.

g/ Tree from which trap is suspended•

Per

trap-day

184 106 251 127

« 351 •

Table 21o—*teek2y trap collections of adult D«, dorsalia la the Palawai and Miki Basinpineapple fields. Lanai, To Ho, 1950* 1/

Trap number g/

177

178

179

180

181

182

Percent female

V

0

1

1

0

0

1

L00*0

Anril

U

0

0

3

0

1

0

100*0

21

0

0

1

1

0

1

66.7

28

0

0

0

2.

0

0

100.0

5

0

0

0

0

1

0

.0

12

0

0

0

0

0

0

19

0

0

0

0

0

0

-

26

0

0

0

0

0

0

2

0

0

0

0

0

0

-

9

1

0

0

0

0

0

.0

June

16

0

0

0

0

0

0 '

-

23

0

0

0

0

0

0

-

30

0

0

0

0

0

0

-

Per

trap-day

.01

•01

J.

.02

.02

.02

3/ Fermented-sugar lure in McHaail traps*

g/ All traps positioned among pineapple plants •

- 352-

Table 22*«~Weekly trap collections of adult D.

Lanai, T. H*, 1950, 1/dorgalla in two pineapple fields*

Trap number 2/

1S3134

185186

187188

Percent female

189190

191192

193194

Percent female

7

0

0

0

1

0

0

1

2

0

0

0

3.

100.0

Atari!

14

1

0

0

0

0

2

100«0

1

32

2

1

2

90.9

21

1

0

2

0

0

0

66,7

0

1

1

1

0

3

83*3

28

1

0

1

2

1

0

60 .0

0

0

1

1

0

3

100,0

5

0

0

0

0

0

2

100 •

0

0

0

0

0

0

-r

May

12

Field

2

0

0

0

1

0

0 100.(

Field

0

0

0

0

0

0

19

5524

0

1

0

0

0

0

) 100.0

£508

0

0

0

0

0

0

26

1

0

0

0

0

0

100.0

0

0

0

0

0

0

•aft

2

0

0

0

0

0

1

100.0

0

0

0

0

0

0

9

0

0

0

0

0

0

-

0

0

0

0

0

0

June

16

1

0

0

0

0

0

100 ,0

0

0

0

0

0

0

23

0

0

0

0

0

0

«

0

0

0

0

0

0

-

30

0

0

0

0

0

0

-

0

0

■20

1

0

66,7

Per

trap«day

ol

•01

.03

.03

.02

•1

.02

ol

ol

.04

.02

.1

3/ Fenaented-sugar lure in McPhail traps•2/ All traps positioned among pineapple plants

ra 353 •»

Table 23*—*fee34y trap collections of adult D« dorsalis in pineapple field no« 5502*Lanai, T. H*, 1950a £/

Trap number g/

201

202

203

204205

206

207208

209210

211

212

213

214

215216

217

218 .

219233

Percent f©sale

1

7

5

52

31

2

6

31

2

2

2

1

2

2

2

2

1

73«1

, km14

2

0

0 -

2

2

2

1

3

41

1

1

Z0

31

2

1

32

75*8

21

1

0

1

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

2

1

■MaauBu

83*3

23

1

0

0

0

1

0

1

1

2

0

0

0

0

1

0

1

1

0

1

0

90*0

5

0

0

0

0

0

1

0

0

1

0

0

0

0

1

0

0

0

' 1

0

0

100*0

May

12

1

0

0

0

0

0

0

0

1

1

0

0

0

0

0

0

1

0

0

0

100*0

.19

0

0

0

0

:,

60

30

1

0

0

1

0

0

0

0

1

1

0

75*0

26

0

0

0

0

0

0

0

0

0

0

1

0

0

0

0

0

0

0

0

0

100*0

2

0

0

0

0

0

0

0

1

0

0

0

0

0

0

0

1

0

0

0

0

lOOoO

9

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

.CM

June

16

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

23

0

. 0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

0

0

0

0

100.0

30

0

0

o

o

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Her

trap-day

olVm4b

•1

•1•dL

olVain

ol

ol

©03

ol

•2

•1

•03

«03

ol

•0A

ol

ol

ol

.1

%/ Fexmented-sugar lur© in l-icPhai! traps *2/ All traps positioned among pineapple plants

-354-

Plneapple fields are evidently a very minor factor in area control on

Lanai* While the number of acres involved may be much higher than such

concentration points as residential areas, and the total number of fliesmay be high, it is equally true that host-free windbreak and shelter areas

yield more flies per trap«day than do pineapple fields, and constitute

an even greater average«.

Figure 15 portrays the percentages of fesiale flies trapped in

the different survey areas during this quarter* The highest percentage

of females was in the pineapple fields* the other so-called "exploratory11areas also showed comparatively high percentages—Kaena, M&nele, and

Halepalaoa* It is significant that while the residential areas and other

fruit attraotant areas (Lanai City, Knob Hill, Koele, and Kaunalei) didnot have percentages of females below 50, as in the two previous quarters*

they nevertheless showed comparatively low female percentages» The only

discrepancies with data gathered during the six months previous to this

quarter is the guava areas—Bench 1, Bench 2, Kapano Gulch (and BurmaRoad)* Here the percentages of females were comparatively lower, as in

the fPuit-attractant areas» It is not understood at present why this

reversal occurred during periods of low populations on Lanai, since when

populations were higher as in the previous two quarters, the average

percentages of females in the guava areas were also comparatively higher

and similar to exploratory areas as Kaena, J&nele, etc*

Table 24 lists the weekly trap collections in the Burma Road

guava areas« These 15 traps were set up in May., and no comparisons are

possible, therefore with previous data*. It is of interest that some

of the traps showed the highest catches for the months of May and June

for the entire island* This cannot be interpreted at the present time*

When area control studies were commenced on Lanai, a survey

was made of the major fruit trees in the residential areas of Lanai City

and Maunalei Gulch* These were reported in the previous quarterly<» The

major fruit trees included papaya, banana, mango, avocado, and citrus•

A survey was made during this quarter for the minor fruit trees in the

residential areas, and the results are as follows s

Tree I

Guava(ordinary)

Strawberry guava

Fig

Peach

51

27

11

11

f flnobHi^

3

5

2

0

1

0

4 0

Kaufa&lap&u

3

1

0

0.

Pomegranate 14- 1 1 1

la addition, thera are approximately 50 pomegranate trees in

the nursery, a young hedge (not blooming) of mock orange at Knob Hill,an older one (not flowering) at Koele, and one old mock orange tree at

355

tf>TtVrfvr<>7rr

66.1&

M1

1

*

1

i

i

1

\m

11

1■®1

w

ill—••.V j

e 15 o - Percentage of female JD^ AQ

during the second quarter "of 1950• Lanfld,trspped in differsnt survey arsas

a?«..nalapau Manel® Lanai City Kaofe Hill Halepslaoa Koele Bench 1 Bsnch 2 Kapano Masnelei Burma Eoad Pineappl«

« 356 -

Table 24—Weekly trap collections of adult Do dorsalis in the Cemetery-Burma Road puavaarea* Lanai, T. H«, 1950* 2/

Trap number g/

221

222

223

224

225

226

227228

229

230

231232

233

234235

Percent female

19

U

6

1

2

140

30

10

222

105

4311

103

0

63*5

26

7

7

242

6

0

1

1

434886

12

2

126

0

59.7

2

11

6

142

2

0

0

1

8

181

61

130

16

0

610

9

2

6

440

31

0

4106

35

66

431

56.1

June

16

0

41

0

2

1

1

0

1

93

2428

4

590

56.9

23

1

0

1

0

1

0

1

0

5

55

98

3

19

0

60o2

"" 30

0

0

1

0

o

0

0

0

1

0

1

6

2

29

45

61,2

Per

©Z.

°3

•5

Q.

•1

.02.

11 *0

3»5

4»3

.5

3/ Fermented-sugar lure in McPhail traps•2/ All traps positioned on guava trees*

Koele whicfe flowers and fruits. There are three mangoes and four orangetrees in Balawai Basin, and four avocados, one citrus, one cherry, threemangoes and about twelve papaya trees in the piggery area*

A survey was also made of the guava acreage in cooperation withthe soil conservationist of the Hawaiian Pineapple Company, and thedelimited area containing this plant was reported with brief descriptionsand napped, in the previous quarterly report* During this quarter,Honolulu poreonnel of the Area Control Project made an intensive surveyof this delimited area on different occasions, in order to determine theacreage involved for different categories of control operations-insecticide, herbicide, cultural control, etc* This work is still inprogress <•

Marked flies were released on Lanai and Ifoui in the lastquarter of 1949 and the first quarter of 1950* The results showed,as: reported in the ptrevious quarterly, that flies released at KaumsdapauHat-bor were found in Maunalai Gulch, Kapano Gulch and Lanai City* thosereleased in Kapano Guloh were recovered at KaumaXapau Harbor and Bench 2,thOc^ reSieased at Kalepalaoa were found at Manele Beach, Lanai City,Maunalei Gulch and Koele, one released in Lanai City was recoveredat Halepalaoa and another at Bench lj and those released in Burma Roadware recovered in Lanai City, Koele, l&nele Beach and Bench 1* Thesedata indicated that the flies move all over the island of Lanai ♦ Inaddition one marked fly released at Lahaina, Maul was recovered at ManeleBeaoh and another at Kaumalapau Harbor, She first instances of inter-island movement as noted by oatches in McEhail traps with fermented sugarlure«

During this quarter, additional marked flies were trappedo Oneblue fly CHalepalaoa) was recovered on Bench 1 on April 7, another atKnob Hill on April 7, and a third ia the area released on April U« Onegreen fly (Burma Road) was recovered in Maunalei Gulch on April 14* anotherat Maaole Beach on Way 5, and on May 19, four were recovered in the areareleasedo Three more green flies were trapped on May 26 in the BurmaRoad areas o It ia of interest that flies were recovered in this regionthree months after liberation* (Traps wore first installed along theBurma Head in May-.) Another instance of recovery after that duration oftime was one yellow fly trapped in Kapano Gulch three months after liberationin that area°

It is of interest that many marisd flies were recovered onLanai in traps usually showing comparatively high catches, as nos* 94,115, and 125o In addition to the intra-island fly movements noted duringthis quarterj an orange fly (Lahaina, *faui) was recovered in the guavaof the Burma Road area on June 16« Skis was three months after liberationon another islando We still do not know the intensity of reinf©stationfrom Haui* Nevertheless, 3 out of 12,000 flies released on Maui warerecovered on Lanai and this iaay be interpreted as at least a moderatereinfestation* Since the population fluctuations on Lanai are relatedto presence or absence of ripe guava, it would be necessary to ascertainthe time of fruiting of guava and other major hosts on Mauio If the time

oa 358 a»*

interval is different, then it nay safely be assumed that the guava on

Lanai is responsible for the populations on that island<> On tho other

hand, if the curve of fruiting of the major hosts on llaui is similar to

that of guava on Lanai, then the question remains an open one for the

time being«

Extensive rearing tests were carried on during this quairtero

As in the previous two quarters, banana, guava, avocado, citrus> ard

papaya (not studied in 1949) were the fruits used- There uas anaverage of 11*2 mature larvae and/or pupae reared from 100 grams of guavafruit in the first quarter of 1950, as compared with Ho7 in the last

quarter of 1949j 11 °2 and 12 »2 respectively, from 100 grains of banana

during these two periods; and 1*8 and 2«1,respectively, from citrus <»

There was, therefore, a marked similarity between the results obtained

in the last quarter of 1949 and the first quarter of 1950« The average

number of mature larvae and/or pupae per individual fruit was also markedlysimilar—4*4 and 3°8 for guava, 14«9 and 16..8 for banana and 2«6 and Io9for citrus for the two quarters, respectively- It was also noted that

the average infestation per unit weight of guava and banana was very similar

on Lanai, that no parasitization was observed in citrus, very slight (e2$and o\%) in banana, and that while the degree of parasitization did

increase in guava (7«9 percent in the last quarter of 1949 as comparedwith 18ol percent in the first quarter of 1950), it did not materiallyreduce the infestation in this fruito

Table 25 lists the rearing data for this quarter* There wore

only two rearings of guava, since no ripe fruit -could be found soon after

the beginning of this quarter* Therefore, the 20 x>©rcent parasitization,

20o7 mature larvae and/or pupae per 100 grans of fruit, and 7*0 perindividual fruit cannot validly be compared with the data of the previous

quarters» Banana (gathered ripe from purchased trees as in tho ji/revioustwo quarters) showed an average of 8*7 mature larvae and/or pupae per100 grams of fruit, and 11o5 per individual fruito These figures are

significantly lower than the 12«2 and 11*2 per 100 grams of fruit in the

first quarter of 1950 and the last quarter of 1949, respectively$ and

14*9 and 16*8 per individual fruit, also during these two respective

periods- Nevertheless, it appears significant that the infestations uere

as high as noted, considering the sharp decline in population * Evidently,

comparatively few flies are needed to infest bananas on Lanai at least

for the number of rips fruit exposed- Whether or not such low populations

could infest ;.juch larger numbers of ripe fruit to the point of economic

damage is an empirical question*

Citrus showed a slight increase in degree of infestation»

Lemon yielded 2<>4 mature larvae and/or pupae j^er 100 grams of fruit and1°3 per individual fruit* 'Hie figure for orange were 4°5 and 2*6,

respectively- However, infested lemon \-ias found in only 6 of the 9

gatherings for rearing, and infested orange in only 3 of 6 gatherings c.

Nevertheless, there is a strong possibility that the Oriental fruit fly

may be a serious pest to citrus on the mainlando While the degree of

infestation is comparatively slight when compared with that of banana

and guava, the insect does complete its life cycle in these fruits«

359-

Table 25-—Rearing data of tha second quarter of 1950., Lanai, T. H.

Location

B-18; H-17B-18| H«X7

B-18- H-17

B-18; H-17

B-18) H-17B-18| H-17B-I8j H-17

B-18| H-17

B-18? H-17

B-18$ H-17

B-18p H-17

B~l8j H-17

B-18| H-17

B-18; H-17

B-18| H-17B-17j H-18

B-18| H<= 3

B-19j H- 4

B«19| H- 4

B«19j H- 4

B-19| H- 4

B-35| H-18B-35j H-18

B-35j H-10

B-59j H-17

|

J ]

!

I

'!

Nanss

Avocado

Avocado

Avocado

Avocado

Avocado

Avocado

Avocado

Avocado

Avocado

Avocado

Avocado

Avocado

Avocado

Avocado

Avocado

Banana

Banana

Banana

Banana

Banana

BananaRanono

Banana

Banana

Banana

No.

5

5

444

7

58

15

5

6

32

5

4

55

41

- • 7 .8

28

9

11

1311

31

i'fttit

Weight

(Grs.)

1240

1172

932

922

892

16721132

1942

34241342

1372

692602

1272

972

677281121032

1012

4132

1022

1322

16921672

3997

Remarks

Soft, ground

Soft, ground

Hard, ground

Soft, ground

Hard, gound

Soft, ground

Hard, ground

Hard, ground

Soft, ground

Hard, ground

Soft, ground

Hard, ground

Hard, ground

Soft, ground

Soft, ground

Yellow

Yellow

Yellow

Yellow

Yellow

Yellow

Yellow

Jellow

xeliow

Yellow

Known period of

- infestation

Initial 1/

March 13March 20

March. 20

March 27

March 27

April 3

April 3

April 10

April 10

April 17

April 17

April 24

May 1

May 1

May 8

April 10

March 20

March 13

March 20

March 27

April 3

May 1

May 8

May 22April 10

Final

April

April

Apz-il

April

April

May

May

May

Hay

May

May

May

April

April

April

May

May

May

June

June

May

1/

3

310

24

2471

7

29

7

23

15

24

2424

15

15

2912

26

23

Larvae and pupae re

covered (number!

Total

41

14

9

0

0

192

74

27

46

66

7

17,

234606

84237

429

84

615208

191

Per 100

grains of

fruit ^/

1*2-9.7

1.1

.2

3.S.8

3»4

4°3

10.1

«JBA»

1.7

7*5Sol

10.48.2

X-0 0 7

36.3

12 «44.8

Per

fruit 2/

tt.2

2.8

2.3

2.7

.4

9.3Io8

9.2

11o0

2.3

4»35.2

12«0

29«6

15.39.3

47 »3

18.96.2

Adul

Oriental

Pruitfly

X"

147

18

2

5810

37

25

5

12

66

241

29

53

22352

95

215

122

92

ts reared (member)

Mediterranean

. fruit

0

0

0

0

0

0

0

o

o

0

0

o

o

0

0

0

0

0

o

0

fly Opius

0

0

0

0

0

0

0

0

o

0w

n

1

o

0

o

1•Aft

o

0

o

16

0

Continued -- Xabls 2?<360

7 Fruit

Known period of

.infestation

Location

Mo

Weight

(Grs*) Remarkd Initial 1/ Final g/

Larvae and pupa©

^J^^^j^^s^m.is^^.h.^

grams of Per

Total fruit jj frutt 2/Oriental Mediterranean

fruttay fruit fly Opius

H-10

B-26- H-10

B~26j H-10

B»26| H-10

B-26; H-10B-26} H-10

B-26j H-10

Maunalai Gulch

Maunalei Gulch

Endo

Endo

Endo

K-2

K-18

E-18

Maunalei Gulch

Lemon 6 282 Ripej picked

La&on 6 352 Rips; picked

Lemon 8 392 Ripe} picked

Lemon 8 422 Ripe} picked

Lemon 7 332 Ripsj picked

Lemon 4 212 &ip$$ picked

Lemon 5 262 Rip©} picked

Lemon 4 135 Ground

Lemon 5 133 Ground

Orange 4 106 Ground; ripe

Orange 5 122 Groundj ripe

Orange 6 172 Ground* rips

Orange 9 820 Picked; ripe

Orange 1 157 Picked* ripe

Qr&'V'S 1 122 ^iwkyd" ri1*^

Papaya 2 597 Ground

ifeuaslei

l&un&lei

Maanalei

Maunalei

Maunalei

Maunalei

Maunalei

Jfeunalei

Ifennalei

H&un&Lei

Giild^

Gulch

Gulch

Gulch

Gulch

Gulch

Giilch

Gxach

Gulch

Papsya

Papaya

Papaya

Bapaya

Papaya

?£X>sy^Papaya

Papaya

3

3

2

3

33

3

1

2

2-

1062

462

7721251

837993

293

482427

Ground

Gixjund

Ground

Ground

Ground

Groi^nd

OroiiGd

Ground

Ground

March 13

March 20

March 27

April 3

April 10

April 17

April 24

May 1

May 8

March 13

March 20

March 27

March 20

Jferoh 13

March In

! April 3" April 10April 17

April *

MayMay

MsyMay 22

x-Say 2.9

*:41

15

AprU 10

May 1

May 1

May 1

May 23

May 7

April 3

April 10

April 24

i-fe.rGh 27

April 24

frtl 24

May 7

May 23

132

11

2Q.

16

1

0.

u

ft.

8

30

0

9Q

0

V*

17

24S2

0

0

2.6

.5

10=L

2.8

0

.7

24»3

2.2

»4i<>4

3*2

2.6

2 =2

6

1

XI

0

76

0

0

5

53

0

0

0

0

0

0

0

2

0

12

O

0

0

0

0

0

0

0

0

0

0

0

0

Continued - Table 361

Location

Koapuiki

Koapuikl

Maunalel Gulch

Gulch

Gulch

Maunalei Gulch

Maunalei Gulch

Cage 9

Gag© 13

Gags 16

Gaga 19

Cage 20

Cage 22

Gage 26

Osgs 23

Gags 29

Cage 31

Cage .32

Gage 35

Cage 38

Uage 40

Burma Hoad

Road

Banana

Banana

Banana

Banana

Banana

Bandxa

Banana

aBauar

Banana

Gu&to

Gusva

FruitKnovn period of

No

75

12

Waigfat

( Remarks

44 6172 Yellow15 2022

7 114392

448

272

956

14 1992

14 1572

14 1792

1612

1422

1892

14

1414

14 1752

\ / i C'l '}

14 1722-

14 1762

14 191214 1S62

14 33227 232

Yellow

Ysliow

lellow

Yellow

Yellow

Yellow

Yellow

lellow

Yellow

Yellow

Yellow

Tollow

XaLlotr

Yellow

lellov

Ground

Larva© and pupae

4 1A0

Initial 1/ Fiaal 2/

fferch 6

i^&rcsh 13

March 20

j April 24

3

May 15

J5ay 22May g

May 8

May 8

my a

S

8

8

May

May

8

Kay

May

May 22

March 13

March 20

Total

April 3

April 10 iApril 24 fMay .15 jJ*an@ 5

June 26

June 26

May 29

June 5

June 5

June 5

Jun@ 12

May 29

June 5 (June 5 (

00 '

fj, —

8 Juas

5 5June 12 \

June 5 |

June 12

March 2?

April 10

206

86

92

10

32

61

193

43

52

12910?

73

75

12322

Psr 100

grams of Perfruit j}/ fruit

j Oriental Mediterranean2/__J Pruitfly fruit fly Qpias

3.3

10«9

7.i

22.420 cS

8.0

7-5

3*94v3

7.2

1.0

93

.35

50

122

"ii 4-547 21.4

2.6

6=6

4-7

5.7

13'15,0

4.06

12=2

.16.1

3.1

6-6

3*79»2

7*6

5,2

5=4.

■ 8.8I06

U 53

3.68o7

4*2

7*5

6»7

I26

10

22

7

1436696

4526

72

45

3421?

44

51

10

29

28

610

0rs\j

0

0

0

0

0

0

0

n

0

0

0

0

0

0

0

0

0-

0

0

0

0

Q

0

0

0

0

0

8

0

n

0

0

0r>

n

0

0

0

0

0

0

2

2

2

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sl^

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363

Therefore, it is possible for a strain of flies to develop that is adjusted

to citruso Also, the fly is apparently strongly attracted to citrus trees,

as noted by catches in McPhail traps in Lanai City*. As in the past two

quartersp no parasit.izati.on was noted in citrus*.

The data for avocado gathered during the previous two quarters

were tabulated in the January-March, 1950 report.. The following is the

summarys 1©1 mature larvae and/or pupae per 100 grams of fruit and 2o2per individual fruit for the last quarter of 1949, i«7 and 5°8, respectively*for the first quarter of 1950, and 2.0 and 4«7, respectively, for the

second quarter of 1950= P&rasitiaation was observed only in tho first

quarter of 1950—0*7 percent • ill! fruit is gathered \jeekly on lanai forcomparative purposes., find infestation is based upon one week°s exposure,usually, of ripe fruit*

Rapaya was roared in the first and second quarters of 1950*The summary results are as follows? 0*6 mature larva and/or pupa per100 grams of fruit and 2«4 per individual fruit for the first quarterof 1950, and 2o6 and 10*8, respectively, for the second quarter• Theseresults are: based on collections in the papaya grove at Maunalei Gulch•The results for the caged papayas positioned around Lanai City arestrikingly similar to those picked ripe from trees in the second quarter—2-4 par 100 grans of ?ruit and 9°2 per individual fruit* ManyMediterranean fruit flies (48 out of 195 pupae) were reared from the papayagatherings in Kaunale.i Gulch during the second quarter of 1950, but nonefrom the caged papaya exposed in lanai Citya The only instance of

parasitization in papaya to date was observed in the first quarter of1950—7 ol percento