bwtuofEnomolog ad Pln ~aat 1vetit
ablropez~the~e)wer coduted aist the adzits of one speciee
of hit-fingd betes Patomms leuola~ (3*ho)) at florsla, Ala*,, during~~~ ~ ~~ *h ro 91* e~so hs tests conf 73m these
.-obaind I 193i-wm shwedthat Of Is the most potent Insectiid
evertesed ~as adut witefrigedbeetles*,
fteMY sedIn ll he xpeimetseported was received from the
owmactres a a 0 ercnt VZVyrpbllte dust, A chemical
ana vi mae b th Diisin@f Insecticide Investigations of this
tiaol.yrrpbylite e 1 pecen M-yrohylit. was also used for
fto~~~~ ~~ cbtwiefigdbelswe colleted. In the fie3A. an albeelesuse Inanyon series of tests were collcted from the
Iffctinss of M! as Stomah 101.0*
In hee ess& tota of aproiately 50 beetle in five cages
wer ued n achrelictin, ndeach see of tests uas replicated
hous aterthebeeleshadbeerlesed on the treated foliage* In
In oderto etemin th na ura wotality, The net mortalitles 'bave
YCRngsIL 1440M)Tagainst the hIte-fringed beetle and
thisveletban atepillre Scintiic ote)Jouo lonInt
Dusts.-In the insectary tests against the adult beetles, peanut
and ayanthems foliage held in 2-once wide-mouthed bottles embedded in soil in 5-inch azalea. flower pots was treated in a settling chamber with predetermined dosages of Odusts containing different percentages of DD! The foliage was held in a position similar to that testing dw field conditions. After the dusts had been allowed to settle for 3 aaiutes, the beetles were confined on the treated foliage .in screen eageso 9 inches high and. 5j inches in diameter. Prior to the dust treatnent the foliage was moistened with a fine water mist from a hand atoiser.
Ifn two series of teste dusts containing different percentages of DDT were applied at a fixed rate equivalent to 11.6 pounds per acre on peanut foliage and 15.5 pomde on chrysanthe m. W oparison a
synthetic eryolite dust (76.8 percent sodim fluealminate) in hifch 10
percent of wheat flour had been incorporated to prove its dusting quality was applied at the same rates. The results are sh in table I.
In this series 0.13 pound of DD per sacre on peanut foliage and 0.6 pound on chrysanthem foliage gave approximately the same ortalities as obtained with the cryolite dust at the same dosages of the dust mixture, From these results it is apparent that, when used as a stomach poison in dust form, D was 69 to 74 times as tosic to white-fringed beetle adults as sodin fluoalminate.
7wther tests were conducted to compare dusts containing various percentages of M when applied so as 'to give the same dosage of M regardless of the dilution. 'his dosage was 0.23 poun=A of W per acre on peanut foliage and 0.31 pound on chrysanthemus. The results are given in table 2.
heae tests indicate that, when DM dusts are used as a stomah poison, the quantity of W applied per acre is the Iportant factor affecting mortality, and. net the percentage of DM contained in the dst
Table 1.-ffectiveness of DDT as a stomach poison against the whitefringed beetle when applied as a dust to foliage at fixed dosages of dust. Insectary tests, 2 replication on each
Tests on peanut foliage ts o nth
Concentration of MD Dosage let Dosage Net
of mortal- of mortalDD ity DDT Ity
Percent Lb. per acre Percent Lb. per acre Percent
0.25 0.03 1 0.04 o
.5 .06 4 .o 13
1.0 .12 36 .16 53
1.5 .17 50 .23 86
2.0 .23 53 .31%8
2*5 .29 73 *39 94
Check (ryolite dust 39 55
I 76.8 percent NaPT1.
Table 2.-Effectiveneel of DDT as a stomach poison against the whitefringed beetle when applied as a dust to foliage at fixed dosages of DDT. Insectary tests, 2 replications on each
Tests on chyateu
ests on peanut foliage ets ohrysanthm
Concentration of DDT Dosage Net Dosage Net
of mortal- of mortalaixture ity mixture ity
Percent Lb. mer acre Percent Lb. per acre Percent
0.25 93.0o 65 123.9 96
.5 46.0 53 61.9 97
1.0 23,0 7 31.0 93
1.5 15.5 7 20.6 99
2.0 11.6 53 15.5 96
25 I 9.3 2 12.4 1. 94
Check rhyolitee dust 11.6 50 155 42
l/ 76.8 percent war.
Spys.---Sprays containing different quantities of DDT and 0.1 pound of a wetting agent per 100 gallons of water were applied outside the insectary with a hand sprayer to peanut and chrysanth foliage held in an upright position in wide-mouthed bottles. The spra wa applied until it dripped from the foliage. When it was dry, beetles were confined on the treated foliage in the manner described for duste A spray containing 9 pounds of synthetic cryolite (95.4 percent sodium fluoaluminate) and 0.1 pound of a wetting agent per 100 gallons of water was used as a check. The results are given in table 3.
Table 3 .-Zffectiveness of DDT as a stomach poison against the whitefringed beetle when applied as a spray to foliage at different concentrations. Insecta'y tests, 2-replications on each
Net mortali on-. .
Concentration of DDT Peanut Ohrysathemum
Lb. per 100 gl. Percent Percent
1/32 11 15
1/16 65 2T
1/ 92 91
1/1 92 93
1/2 ./ 97 95
/ 8. percent Wa3AlY6.
The sprays were about equally effective on peanut or chrysanthemum foliage. The spr-,.s containing 1/S pound or more of DDT oer 100 gallons gave a net mortality in excess of 91 percent, and 1/9 pound of DDT gave the same mortality as 8 pounds of cryolite.
Effectiveness of MDT as a Contact Poison
Dusts applied to the beetles.--Dusts containing different pe centages of DDT in pyrophyllite were also tested in the insectary as contact poisons. Adult beetles were placed in wooden-frame cages, 12 inches square and 1 inch high, covered on the top and bottom with 1&4esh screen wire. These flat cages were placed in a settling chamber, 1/4 inch above the bottom surface. After the dust had been ejected and allowed to settle for 3 minutes, the beetles were immediately transferred to untreated foliage in clean test cages, and the mortality was recorded.
Te results of one series f tests in which the rate of application was equivalent to 11.6 ponds of dust ner acre ale shown in table 4. Only the 5-percent dust gve any appreciable mortality. Treatment with cryolite and pyo llite were used as checks.
Table 4.-Effectiveness.of DT as a contact poison against the whitefringed beetle when applied as a dust to the beetles at a
fixed dosage of dust. Insectary tests, 2 replications
Concentration of DDT of Net mortality
Percent Lb. per acre Percent
0.25 0.03 2
5 .06 2
1.0 .12 1
1.5 .17 3
2.0 .23 9
2.5 .29 7
5.0 .59 46
Cryolite dust=- 2
1 76S.8 percent Na A176.
Dusts containing 2.5 and 5 percent of DDT were also applied at different dosages in order to vary the quantity of DDT applied per acre, The results, which are given in table 5, show that, within the limits used, the mortality increased as the quantity of DD per acre was increased. Treatments of 0.47 pound or more of DDT per acre showed more than 51 percent net mortality. The heaviest treatment, 0.93 pound of DDT per acre, gave 90 percent net mortality.
Purther tests were conducted to compare dusts containing different percentages of DDT when applied so as to give the same dosage of DDT. This dosage was 0.31 pound per acre. There was considerable variation in the results with the different concentrations. The dusts containing 1.5 and 2 percent of MDT were the most effective, and both of then gave approximately 50 percent net mortality. The detailed results are given in table 6.
Table 5.-3ffectiveness of WXT as a o:t poiso"I against the whitefiuge4 beetle whez, app 'les as a 4ust to the beetles at different dosages of DDT an&4 dust. Znsetary tests, 3
Concentration of DDT Doe~e of- Net mortality
Percent Lb. per acre Percent
2.59. 0.23 13
1224 .31 25
15.5 :9 36
5.0 12.A :62 73
15.5 .78 88
11 18.6 .93 goCheck (cryolite dust>' 15.5 ows0
~J88.9 percent Ta3Al]16.
Table 6o-3ffectivense of DD! dusts as a contact poison against the
white-fringed beetle when applied as a dust to the beetles at a fixed dosage of DDE. Insectary tests, 2 replications
Concentration of DMW of Net mortality
1.0 31.0 30
1.5 2o.6 51
2.5 12.24 23
5,0 6.2 22
Oryolite dust 1115.5 0
Pyropb~v11ite 23,P2 0
wI76.8 percent laAlJ6
Must.s lied on th soil,-Dbsts containing different percentages .them directly on the soil sace. The
soi wa Asodin 5-nc &ae flower pots, in ec of which a widemouhe bttle was embede, an @Vo.A In the settling chamber for 3 mpe ages of the dt* Clean foliage ws then
plaedin bottles. Newl collected beetles wee introduced into se cea a to crwl on t wire before the cages were
S t pots. e e avoid plac the ats
dinctact with the treated soil ufe. fe quantity of
folageuse inthese tests was approimtely twice that used in ote Sthe side of the cage at seeral points,
priting th aft. to reach it without cralin an the lol. Under thecoditon o thim test most of the beetles moved from the foliage to th soil to oviposit or rest within 14 hours. Under field conditions aduts are an tb sufce of the soil or,hours duing each da than
ets ontaiuI 2,5 and 5 percent of W! were applied at different
aIn the tests where the applications were made directly to the b es* fte t, gven in table 7, show that the liter
dosae gae greater mortality when applied to the soil than when applied direl to t beetles (table 5). Since mortality continued to occur for a l peri the tests were continued for 3 additional da.s, or a
tota of 7 ds* te tw heaviest dosages gave sligtly heater MortalIty at the wa of 96 hd6wa when applied to the bo tles, but not at the and of 161 haus*
kble 7. Ifeotiveess of WT as a contact poison against the whitefbeetle when applied as a dust to the soil surface at
different dosages of MT and lust. XnseciarY tests, 3
n b, per a Percent Percent
2., 0.23 19 29
15.5 *960 68
5.0 12,14 .62 714
15 5 .7O 7
15.6 9 4
Ch c c y l e d s r 5 5 -2 5
"on the beetles.-Srays containing different
quantities of DD Tanuncd of a wetting agent pr 100 gallos of water were tested by applying the sprays directly to the beetles. The beetles were held in wooden-frame cages eatly like those used i the
lust tests. The sprays were applied with a small hand prayer utti they dripped from the beetles. After the beetles bad been allowed to dry, they were placed in clean cages and provided with created foliage for food. The results are given in table S.
Table S.-3ffetiveness of IT as a contact poison ainst the whitefringed beetle when applied as a spray to the beetles at
different concentrations. Ins4cta'y tests, 2 replication
No C:' oncnrton Ne
oncentration of DDT mtality of DDT
Lb. 2er 100 gal. P8eint Lb. er 100 g, Percent
1/64 17 1293
1/32 20 Checks:
1/ Water 1
8514 peh~ent NAl76*.
Sprays amlied on wee.-Two sprays were tested to study the mortal cused contactwith treated surfaces. The sprays contained 24 pounds of DDT and 0*6 pound of a wetting agent per 100 gllons of water, and 20 pints of fish oil was used in one of the sprays. The inner surfaces of the cages were sprayed until dripping. After the spray bad dried, newly collected adults were placed in the cages for different periods of time and then transferred to untreated foliage in clean cages. The mortality records were made at 2-hour intervals for 96 hours, but since practically all the beetles affected died within 4 hours, the mortality was thereafter recorded at the enad of 19 hours.
A few tests were begun within 24 hours after the cages had been treated, a second series was started after 2 to 7 days and before the treated cages were exposed outdoors to weathering, and a third series after 13 to 22 days and the cages bad been exosed outdoors for 6 days, during which time 5.6 inches of rain fell.
Te results ae shown in table 9, In tests started within 24 hours after treatet, the two sprays wee about equally eff ective wn aduts me confined in the treated cages for 1/2, 1. a 16 hours.
In the secon series the beetles confined. for 1/4, 1/2, a I hour were
lesi affected by the spra contaiiing fish oil t the r
without fish oil, but both sprays wee equally effective after 16 hors The fish oil had dried and harened at the time of this exosore. Zn tests oondoted after the cages had ben exosed outdoors, both spras failed to Iil beetles confined fTo 1 hou, but after 16 hours the spr containig fish oil yas the more effective.
Table-9 .- fectiveness of DD as a contact poison against the whitefrined beetle wh a1pied as a spray, with and without fish
oil, to the surfaoe of cages
Time after treatment Length of Net mortality
when tests were begma exposure Tests Without fish oill With fis oil
Surs Number Percent Percent
3 soreexposure to outside weathering
1 1/2 1100 914
1 96 93
16 1 100 100
2-T7 1/1 24 63 14
1/2 3 8z 11
1 2 914 214
16 1 98 98
After exposure to outside weatherit
13-22 1 1 0 0
16 3 20 59
Toxicity of Plants Grown in DDT
In Dseeber 19143 MT was thoroughly mixed with soil at the rates of 0 416, l.o, 2,06, 4.17, and 10,41 grams per cubic foot, which is equivalent to incororating 10, 25, 50, 100, and 250 pounds of MT with the uper 3 inches of an acre of soil. In 1944 peanut plants were grown in this soil. Approxitely 50 adult beetles were fed for 22 days on the foliage from each treated plot. In no case was the foliage toxic to the beetles.
Insecticide Applied on Foliage
To determine how long DDT would remain effective against the white-. fringed beetle under field conditions, 5 tests were made in which dusts and sprays, were applied on pDeanut and chrysanthemum plants, 3 tests on potted plants and 2 on plants growing in the field. Either 3 or 4f field cages 2)4 by 2~4 by 30 inches were utilized for each treatment, and 25 to 35 beetles were exposed in each cage. The dusts contained either
2.5 or 1.5 percent of MDT in pyropyllite, and were applied at the rates of 0.314 to 0.38 pound of DDT per acre. Two sprays were used, a concentrated spray applied with a paint sprayer and a dilute spray applied with an ordinary pressure sprayer. The dilute spray contained 0.2 pound of DDT, 2 pints of fish oil, and 0.1 pound of a wetting agent in 100 gallons of water. The concentrated spray contained 4 pounds of DDT, 20 pints of fish oil, 1.1)4 pounds of a wetting agent, and water to make 100 gallons. The quantity of DDT applied per acre was not determined for the sprays, but it is known to have been greater than for the dusts. The dilute spray was applied until it dripped from the foliage, and the concentrated sprey
by enveloping the plant in a light, fine fog.
In the tests on potted plants, after the treatments the pots were
plunged in the soil outdoors, where the plants were exposed to weathering for different pe-riods and then placed in field cages into which adult beetles* newly collected from the field, were introduced., In the tests on field-grown peanut plants, the plants were covered with cages Immediately
after treatment. Beetles-were released immediately in some of these cages and at specified intervals thereafter in others. The mortality was determined 96 .hours later.
The net mortalities and rainfall for the individual tests are given
in tablets 10 and 11. The dusts remained effective for a shorter period than the sprays. In the mortality tests begun immediately after treatment, the average net mortalities were 77, 96, and 9)4 percent, respectively, for the dust, the concentrated spray, and the dilute spray. After 5 days' exposure and an average rainfall of 3.12 inches the dust was only 39 Percent as effective as initially, while the concentrated spray retained 93 percent and the dilute spray 6b4 perceuit of its initial killing power. After 10 days of exposure and an average rainfall of 5.07 Inches, the dust gave 6 percent, the dilute spray 26 percent, and the concentrated spray 67 percent net mortality. In tests begun 15 days after treatment, and after an average rainfall of 7.95 inches, the dilute spray gave 13 percent and the concentrated spray 56 percent net mortality.
t to to w1% 0 td*%%D cm
0 wo a ta%Vs W% 01% Ito %a
"4 42 43
9 OOv4 &C)
8 pal 1
0 r-I 0.0%
-0 qr4 V4 tl-%.O V4 I- 10 r4
41 U 0 1 6 0 0 0 0 0 0
1 4D u -P cu Cli LCA %Dcoo
-P 43 %4
0 ##4 43 0 0
od r4 % CY% 0 0 CYN
0 0 co -P o"JA 0 r4 LC% 40 r4 LC1% t-- ON
4x r-1 0 0
0 431 0 clu a% cs (YON 0
0 0 4 qg
0 A P4
0 0 4j
0 LCNo 0 LC1% 0 U"% 0 UN 0 UN
4a 0 42
01 Ogggg IN 0 a 0 C
4.0 0 -P
01*4 A U
.. ..... ...
Inseciid Applied in Soil
In July 19)44 beetles were introduced into outside rering
c b 15 inches in diameter by 30 inches dee, in some of w Sa b mixedeinto theper3inhes of soil amonthprevat rates of 25, 50, and 100 pouds per acre. Uon emin tion In Agst the mortality was much higher in the treated than i th untreated chambers, Accordingly, a series of tests was set u to s the mortality of beetles caused by DDT when mixed in the
On uguta2 fieldocages 24 by 24 by30 inches were placed
over soil treated with DT in the ipper3 inches at rates of 5. 109 50, and 100 pounds per acre, In these tests potted chrysanthem plant. grow in untreated soil were placed in the cages as food for the beetles. Two cages were used for each treatment, and 25 to 35 b l w exosed in each cage, Tests we started in these
cages on Ast 22, August 30, and September 11. The first test was cone f 7 and the other two tests for 12 days. The
e mortalty for the three'tests was 31 percent for the
0 and. percent for the l00-pound dosage, and for the two
approximately the same as in the untreated checks.
Ding 1944 field plots of cotton, peanuts, and corn inte.
cropedwith yelvetbeans weres treated with a number of applications S The DDT was applied in three ways-as a 25 percent dust in
oflit., as a dilute spray, and as a concentrated spray. Tne spryswere of the same composition as those used in the field-cage tests. Duing the sumer each plot received three or more applications at the rate of approximately one-third pound of DDT per acreapication Jo f6liage injury to these crops was observed.
Inetar tests were conducted at florala, Ala,, in 1944 to
detrmne the effectiveness of DDT against the adults of one species of white-fringed beetles (Pautomorus. leucoloma (Boh. ) ) DDT dusts
adsprays were effective oth as stomachandcontact poisons*
When used as a stomc poison M)T in dust form was 69 to 74
tie as toxic as sodiu fualminate, end a spray containing 1/9
pudof DDT per 100 gllons of water was about as effect ive as a spray
cotani 9pond of sythetic cryolite (5,4 percent sodium fluoaluintef These tests indicate that, when used as a stomach poison, thequatity of DD aplied per acre is the important factor affecting
moraltyan not th percentage of DD contained in the dust.
UNIVERSITY OF FLORIDA
02' 3" 8' 7" 3r' "4
004tact, povada -U*: in dust 'kOP66
tIe-beetles or on the surtais of thb
1-10 pound or more of DDT per 100 gallons. applted dir
09;ed not mortalities in Mesa of :6o pe'reent'.' Aftlt
'te Alethal dose of MT from contact with surfaces treated*llk,
or 4usts. The use of fish oil ais an adhesive in a MT sprv:
sed the period adults must remain in contact with a treated
etol4counmlate a lethal dose when the treated surfaces were not..
to weathering. Tiah oil, when used in a spray, increased the
RdLon.0f, WT on surfaces exposed to outside weatheringo
%9,. foliW, of peanut plants grown in soil containing M)T was not ilk'a to the beetles,
field-cage tests DDT was applied as a dust, a dilute spray,
1,&.c4damtrated spray to study the duration of effectiveness of th*440"
application under different weather conditionso The cones*Wremained effective longest, and the dilute spraywas
%,Opow than the dust* Applications of 50 and 100 pounds of WT
'400'in Us upper 3 inches of soil gave appreciable mortality of
'-',q*ga4 on the treated soilp
"*-""f0i'ia@e injury was observed on cotton, peanuts, corn, and
Deana in::field plots that received repeated applications of a dilute spray, and a concentrated spreye