Experiments with DDT conducted by state agricultural experiment stations, agricultural colleges, and other non-federal r...


Material Information

Experiments with DDT conducted by state agricultural experiment stations, agricultural colleges, and other non-federal research organizations
Physical Description:
1 v. (various pagings) : ; 27 cm.
United States -- Bureau of Entomology and Plant Quarantine
U.S. Dept. of Agriculture, Agricultural Research Administration, Bureau of Entomology and Plant Quarantine
Place of Publication:
Washington, D.C
Publication Date:


Subjects / Keywords:
DDT (Insecticide) -- Testing -- United States   ( lcsh )
Agricultural experiment stations -- Research -- United States   ( lcsh )


Additional Physical Form:
Also available in electronic format.
General Note:
Caption title.
General Note:
Each report has separate paging.

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 030290097
oclc - 779854777
System ID:

Full Text

n order to further i research on the ini tii
Ey an Plant quarantine has invited State .
s for rproduction and distribution, especially -,
sults of experiments with DDT conducted mainly du,. _1 doing
no review of the material submitted by the various agencies has been
eythe Bureau. The only change that has been made in the statements
asitted has bee alteration in arrengangent to make them as much as
le uniform in style, and,in some instances, inserting scientific

There is a heavy demand for information regarding methods of formula-
napplication and results of the use of DDT on various crops and against
'Mayisects -It is felt that the inf ormation obtained by various research
es in this fieldwill accelerate the quest for more effective methods
trolling pests of food, forest and fibre crops as well. as those of
ok and man. Some duplication of effort may also be avoided and per-
pre complete coverage of insect problems may be obtained by distrib-
results of experimental work promptly among research groups.

It.should be borne in mind that these results are necessarily of a
inary nature and that avoidance of definite recomendations has been
eful" Attention is also directed to the need for constant considera-
f.related but nonetheless important aspects'of the introduction and
read use of a new ineticide. These include the effect of such
ials on beneficial insects and wildlife, on plants both directly and
h accumuations in the soil, and the ever present matter of res idues
may be unightly or may prove toxic to man and domestic animala.,

These reports on DDT experiments are not pres,)nted in any particular
rwith reference to subject-matterdate of receipt, or otherwise,
J. ..... e

nN': ?l
EE l ai N
ii i i i i i i i ii l i! i i i i i i i ~ i i i i i i i~ i i i ii i ~ i i= i i i i i ii i i i i i i i i i i i i i i i i i i ii i i i i i i i i i ii i ii i i i i i ii i iiii' lii Iii i i' i iiii iii l il i i i i i !ii~ ~ i i i iiii i i i'i i = i i i' ' i
i = i i i i i i i i i i ii i i i i i i i i i i i ii i ~ ii i i ~ i il i i i i i i i i ii i i i i il i ii~ l i i i i l i i i i ii i i i i i ii i i i~ ii i i i =ii i i ili i l i ili i i i i i i i i i i ii ii i ii i i l 1 =i l i i i ii l
Biili~~it~ asl:. .~, ~1 .
$li ii~:l~ llii:I ::j ~Ii
ii~l~, ~F~~~~
IiiiBa J

1. "";;'"" NN N

:E: ;N3iNNs ~:~~~~
:R'I E ..I 13
;;L :,:i' ,
i = i= ==
i iii ==" ii ililiiii i =iii iliiii iiil iiiii! i iiiiiiiiliii iiiiiiiiiii;ii
N=1~': l!.:.;. n @~ Hl@NN ~ ~n~ ~,~:i



II1II ase~r?! ,, Y;""' al~~
"" '""~~~~j~~r, n;~ ~ii~l ~ ........
";iP ~p~~:a ililil~i~ll
;'"". nn;.i illlj E:ElaE"""'"""'~:',Ilr"""""""""E"" ii-~f"~r,~~-~
I"~~""l'~1~-,~l:lli;~~;"~ IE ~ '~"I" :""i;i~
~Ei"clcr liiilEll'~:i;"lr#RF" "dar"""
ia8i~ i
"" :."~C ji."i~l I .Irel"':..l~:::, ::,~ :?~~i,'wli:iiiiili IE'::~~....:: ""lgc;Y~:I, r
B r.
~~ ~~~~:liii~~ ii~o~; ~i~111l
;ii .,~,,~~
Ilil nln!3 il. Irilrnl :: -" '" ""1:11 11 r-i
r: i~anx;;l;aa~;a ii~~ 8:l~;i;i;ij~l,~U ~~~~~
v?~:nr:l.r~iw ,rni.:i,,?: r .I~: ~~1::: B~~,n:, ~~i",:""I,;~
..i""~ ii ~a~~~
'"''* "" ~~#'":W: :,,id~~::i:i:i.: :-::
"RC.W."~;~~;j '~:l:~l:Ps;~r'~l:~~:~ 9r118 .,j~ j. ~iaa: i
,:e~, ~~iirla~,,~
i48:s~~l81 ~"~'"""",~ii~li,~~~ ~ lil.
IUVliYIIU:ulnlu"?IElllltl '"'""' """': ;i: rr?'sr' I[HI~I s
iis ii :~ ~z~~I~~i, s8 ~E:l I,.$
I s.;wU~n ~rl ,,
B~i~cll~,n, 8~.~l;b ~,;
ri~i:il. n~,,,si~~ n.;ici I;, p~
12~'":Lr'~""'""i~l ~:i~"'~:;'~'~~~~..,;~~~.:'""l'"""i., ._::,.u:; "
I1a B'Ei~a:"EIIII~~~; :;:B~~a~,~~;~l ra r~;~iE ~: ~"'~ .iip~. ii'
"."".~ r~;:~ B~ ii 15~
~;:: ~iB~~BI EI, 1 :
gl?~?~~,I, ::~~~~, r:~;l~;ii i~~i '~lr'~""
"""'' lir~iC:,l~ ~:q,::;j~:~~'~~~:;,:;,,,:h;,':i: iil??-;rr i- i
bl:I ri"i';
~MsV:,r:': I~":'
g,~:~~ ;t~~lliW' ~I;
l.lQ: P~;; (
""FEi;6;~ aZa
~%:~~I:~~ g.,,?~~~~.::;.,,~:::~:~~ill- iiiS3~"::~~ :B::::~:,.I:i:1;~'~"~~ I ~~'i.":~" ..A
:;r;-r~;ii~~;i;; ~:"~ I'B~;"~I~.. ,~
~:,~n;i~i~~W,~, ~i~E;a~~:i~~Wji~81~111,~:~;~~;; ~"'"I~~"~ ; a .r?
I~i~lll;ii~,i~~i ~ ':~~III ~~I IU";':~~~~ j.~: a5~:B~i~;,~;iI~ ~~k;;
~;.~1i~,:,, :-~,~sC.2~ ;:r
: :~l:BIBHR:nl:l:c~rlJIIIIAU:";" :"'""""118.1:i~ji
1~9iBi~ S;,ili"iUl;~iii~8:ii'8,~. i~ ir
~~ix :81
,,., ; inl,~ "k~"~ ~i%lk .:la,,~:.~:~~~::: ,i:l ,~~:ns~eIEri:
;I ;.~i~.,,i~;:;
~~l;.:*:.:lr""~:::: ~~~'~~~~ :~" ~ E: rl:
I ~:s' ~s~ri~i";. r~l~~ ';;"-B
:i~Il:ii;~ I' ~E
~i~i~": ~~ "" ,
II "ii:..
:;~l;:~~;i;~~i; :~.~.;""
;~;r~;~;J:~, ~11~6~:~ ~~~~~ ,ag$~~~~:~~:, (IY
I;i~EC I
" ~~'~~;~"~~~'' "'"~""~";i,,,,,.., i, ....,~.~:,~i~; ~.: ~~ ~~~;~~~: Hff I:,,a:, '
I, "';,l;n
" (!:.;I,::"al~'~~~; ,~: ~~~~l',w ~; ,i ~~:,,ii,~ i~
i9"=."~.~: i
sr;~%~~i' 911~,~ri;I~~~
,, plisa~ qs~ i ,, Ilr ri~,li~:~Eii~lle~~ ~~~:
~"'Xli ~.'rPI
IEC,;a~~a; -~~~I~ ~~
~S~. :lr5~,, .~c _,ii ."!" .- '-:."~183Vi,~l~ ~~~~~: '"'~:.:.." g~,a,::~~- :i, a, E~~ ~i~~'A ~~.,:II'""~~'~~"
~~i~~ll~ ,::~~i~ ~I.a4~.
.~.W~~:~'~i:""~I~~~Ea:o,,-- .;2-
:r~?** :~i:: :~II: ~:~i~ : ;; :~~IF"~;~~"""~4~ ~;E
*~.i~ ~ ~.,3:~::iF* i:W
;li :,~~~ "E
':l:li' '.',:r:l: ~i":~.~ ,,,,-:c~~ ,r:s~ ~:91~:1" '": ~~; :Y :I



Experiments with DDT Conducted by'State Agricultural
Sxper met Stations, Agricultural Colleges, and Other
iNon,-Federal Research Organizations


Potato Insects

In 1944 field experiments similar to those of 1943 were conducted
ith DDT using comme cal fields of potatoes and the plots at the Experi-
ment Station.

Near East Grand Forks, Minn,, 3 applications were made of 2 distinct
dusts, 1 iat 5 perent of DDT alone in Pyrax and the other at the same
ngth and 5 percent of yellow copper oxide at the rates of 15, 20, and
25 pounds per acre in each successive treatment between July 8 and August
1944, on1.73 acres each in comparison ith 11 other insecticidal

At Orookston, factorial experiments consisted of 18 different treat-
mens, 4.of which consisted of DDT, applied 3 times at 15, 20, and 25
pounds per acre, on 0.216 acre area each.
'', *
I ., DDT at 5 percent alone in pyrophyllite.
2, DDT at 5 percent ith 5 percent of yellow copper oxide in the
-same catrier. -
3.- DDIT a percenit with tribasic copper sulphate at the level of
7 percent of metallic oopper-in pyrophyllite.
4. DDT at1: percent with 5 percent of yellow copper oxide in

ar Fiser, Minn., four DDT dusts at 25 pounds per acre were used
for r ual vale over 2.544 acres each.. All dusts used in pyrophyllite
carrier as follows:

I. DDT at 5 percent alone.'
2. DDT at 5 percent with 5 percent of yellow copper oxide.
DT a 3perent with 5 percent of yellow copper oxide.
4 DDTat 1 percent Tith 5 percent of yellow copper oxide.

dition to thee experiment a field of 2.5 acres of potatoes
w dusted 'b an airplai-e, using 5 percent DDT dust with 5 percent of
yeow copper oxide at 25 pounds per acre.

1$ ; "
IL~~~A >;,


On the basis of these experiment it is apparent that DDT proves to
be one of the outstanding insecticides for the contro of most oth
potato insects, confirming the previosly reported results. From2 years
of experiments, it is evident that while DDT has a considerable resid
value on foliage under field conditions, it certainly does not possess
very long residual properties'outdoors as compared with the indoor e

The combination of DDT with 5 percent of yellow copper oxide, as a
rule, gave quite consistently somewhat more effective control of most o
the potato insects than the same concentrations of DDT alone.

A. A. Granovsky

POTATO FLEABEETLE.--Epitrix cucumeris (Harr.) is effectively controlled
by as low concentrations as one percent, especially when the dust actua
-hits *the.insects. Almost without exception the counts of fleabeetles at
the end of 24 hours after dusting reveal a nearly complete mortality. In
'repeated applications highly significant differences between treatmynt
means were obtained. Residual value of a single application of percent
DDT, against the high population of emerging second brood showed that
treatment means do not differ significantly from the check.

POTATO LEkFHOPPER-.--Emoasca fabae (Harris) is controlled best by the
higher concentrations of DDT used. In the majority of the tests at re-,
peated applications, the analysis'of variance reveals highly significant
differences between treatmeht means. The residual valte conspicuously gave
more satisfactory kill of the young nymphs than the adult leafhoppers.

MIRIDS.--The mirids, such/Lyeusi rate .sis oblineatus' (Say), Adelphocoris
lineolatus (Goeze), and A. rapidus (Say) also respond to treatments by
usually by highly significant differences betWeen means, although the re-
suits are not always consitent.

COLORADO POTATO BEETLB.--Lentinotarsp decemlineata (Say) was killed with
remarkable ease in the adult and nymnhal stages within 24 or 36 hours after

Truck Crop Insects

During 1944, DDT was extensively used in a series of experiments
against various truck crop insects in Minnesota. Specially designed test
were made for the control of the leafhoppers in carrots, the. corn earworm
in sweet corn, melon and cabbage insects, onion thrips, and others. A
brief summary of the tests is here presented.

. . . . . .


ISPOTTD LEAFOPPER (lMacrosteles divisus (Uhler)).--Associating with
-vis dieease, this ~insect. cruses seribus dpmage to commercial carrot
ops. A large carrot field was divided into randomized and replicated-
lots with an area of 1.335 acres for each of the six treatments, two of
wich contained DT at 20 and 25 pounds per acre in three applications
per' season.

DDT Pt 5 percent alone in pyrdphyllite.
2. DDT at 5 percent with 5 percent of yellow copper oxide in
S .pyrophyllite.

Both combinations of DDT'gave very satisfactory results in controlling
this insect, and in giving a much greater percentage of disease-free
carrots as compared with other plots.

C0,i AIn testing six different methods of ear treatment in
replicate plots the DDT dusted plot had 3.56 percent infested ears as
against .7.26 percent inthe check and only 0.99 percent in'the oil treat-
m'ent .

CABBAGE INSECTS.-The imported cabbage worm, Pieris rapae (L.), the
cabbage looper, AutoranPha brassicae (Riley) and the diamondback moth,
Putella maculiDennisi (Ourt.)larvae were comoletely controlled by a 5 per-
'cent DDT dust in combination with 5 percent of yellow copper oxide in
pyrophyllite dusted lightly five times during the season. The plants in
the check plots were so badly riddled that not a single edible head was
formd. The DDT dist was by far the most effective of several insecticides
tried The bage plants treated with a DDT combination were absolutely
ree from ho and assumed a healthier and conspicuously greener appear-.
ance in pason with all other plots.

stages, the cucumberbeetles, Diabrotica vittata (F.) and D.
duodecimnounctata (F.), were very effectively controlled in replicated plots,
established in heavily infested commercial pl-ntings by 5 percent of DDT
alone and in combination with 5 percenat of yellow copper oxide. On the
ether hand., they completely failed to control the melon aphid, Aphis
gossypii Glov., which seriously damaged some of the dusted plants.

BE LAF BE-TLE.-Controlled by 5 percent of DDT in pyrophyllite in a.
small pa-fch of beans grown in a Victory garden.

I THRIPS. reliminry labortory tests with several concentrations
of DDT dusts and sprays showed a definite possibility for controlling this
pest, especially by higher concentrations of DDT.

A. A. Granovsky

SMiscellaneous Insects

A few additional experimental uses of DDT were made during 1944,
epeially fr the protection of young apple nursery stock and against
greenhouse insects and others.

wa dusted with 5.perent D st tA 1 the seasonat 1 nth
intetrals, comparing'its effectiv/eness with, .x lof4-4 50
borddaux mixture between June '21 ad Au ~t 1944,also sing che
The la s t three bordeaux sprays were mixed i ith nicotine u te 3/4
pint per 100 gallons. Both reatments controlled the leafhopr
equally well. Nicotine. suiphate.took fairly good care of hig i D
in the bordeaux blockad tih aphid popationn'ths
greater, showing that DDT controlled som'm of- thm, The avergeannua
growth in the DDT block measured 173 inches,in th b ax blc
,inches, and in the control block 16.05 inches, showing thatfeqnt
bor.eaux application depresses, while dusting iith-lDTlightly increases
the nnnual growth of youing apple nursery 'stock.

DEPLUMING iJlTE( (nemidocoptes gallinae Raill.).-A potato gr r, coope
.tng in the experimental .cntr.l of potato insects, cm ined that
.phickens do not thrive and re losiiig feathers. Uponh e'ination it
'found that they were badly infested -With dep uing-mites. 'Th" e; n h use
and the chickens were dusted with a,5 percent DDT dust. After 2.e
treated chickens were iamost completely free from the mites and began to
put on'new feathers. Thesecond application comletly -rid he bir of
the pest.

A. A, Grano vsky

Insects Affecting MaPn and Ania ls

HOUSEFLIES AND 'STABIiETLIES.--Two methods of utilizing DDT were Iusd to
control flies in barns. In one test all the screens werepinted with
5 percent DDT in kerosene. In the other experiments Nocid-A-5 or NeocidN
A-20 were used as water suspensions and sprayed on the walls and ceiling

.Painting the screens resulted in the killing of large numbers of house,
flies and stableflies, but the amountof surface-treated ws too s.mll to
give satisfactory control. It is estiated thPt the opulti wa e ce
by 30-40. percent after the screens here treated.

*A water suspension of 2 percent of Neocid A5 gavefair ontrol for
about.1 month when apolied to walls and ceiling as acoarse spray. Both
a 1 percent and a 2 percent suspension of N6cid A20 gave much better con-
trol, with the latter'giving good results for6-8 weeks One bar with
about 5,000 square feet of sprayed surface was kept free of flies all sum
with two applications of 18 ggallons each of a 2 percent suspension of
NTeocid A-20.

A. C. Hodson

- -


Experiments with DDT Conducted by State Agricultural
iExeiriment Stations, Agricultural Colleges,and Other
Non-Federal Research. Organizations

Department of Zoology and Entomology
VMississippi Experiment Station
SState College, Miss.

(Note: The test against the pickleworm was a regularly approved Yississiopi
Experiment Station preject. All the other tests were conducted after hours
or-when spare time could be found and it was not possible in some cases to
give the attention to details which would have been desirable. The DDT dusts
used in these tests were furnished by.the Geigy Company as Gesarol A-l, A-2
and A-3.)

Vegetable Insects

PICKLEORM.--This test was made on an acre of cantaloups which was divided
into 60 plots. Treatments included 1%, 2%, 3% DDT dusts, 1/2% rotenone in
Pyrax, and a mixture of 30% cryolite (Kryocide), 6% Cuprocide, and 64% Pyrax,
each replicated 10 times. Dusting began at blooming and. was continued at
wekly~intervals until 10 days before harvesting started. Four effective
applications were made at 15 to 20 pounds per acre for the first and 25 to
30 pounds per-acre for the last. The average percentage of infested melons
at harvest was as follows:

% DDT-----------5.5 (Range----0 to 15)
2%' DDT--------4.4% (Range----O to..ll.6).
3% DDT- ------------4.4 % (Range----0 to 9)
1/2 Rotenone-----8.9% (Range----3.9 to 18.8)
30% Cryolite-------7.3 (Range--.-4.2 to 17)
Chek-------------11.2% (Range----6.8 to 20)

It is believed results would have been considerably better if apolica-
tions had been ontinued until harvesting began or even later..

SQUH RB.-This test was conducted in the field on mature squash plants
already severely damaged by a heavy infestation of half-grown and older
nymphs and aults; hence the number present was not known. -Dusts conta~fing
1, 2, and 3% DDT and a spray of 1 pound DDT in 100 gallons of water were
applied. At the end of 24 hours both adults and nymphs were still active in
Streatments. After 48 hours very few bugs were seen. Careful examination
72 hours after the application showed large numbers killed by each treatment,
bt a few nymphs and adults survived each one, the largest number of each
in the cage receiving the spray.

General Plant Feeders

A LEAF-FOOTED BUG (Leptoglossus phyllopus (L.)).-This bug occurs in thou
sands on cowpeas in Mississippi in late summer. Using cowpea plants in
screened cages 20" x 20" x24," with 25 adults in each test, the following
treatments were given, beginning September 7:

: :_ Record of mortality

No. Treatment 24 hrs. 48 hrs.* 4 days: 9 days

1 Check No treatment 1 4 5 7
2 Plant and bugs dusted with
3% DDT 15 24 25 --
3 Plant only dusted with 3% DDT 0 5 5 24
4 Plant only sprayed with 1 lb.
DDT in 100 gal. HO 3 3 7 24

In another test a 1 DDT dust aoplied directly to the adults gave no
mortality in 24 hours, 56W in 48 hours, and 70< in 72 hours. A 2' dust
applied directly gave 70% dead in 24 hours and 85% in 48 h'ours.

Euschistus servus (Say).--This pentatomid is often very numerous on cotton,
okra, beans, and other crops. Practically no mortality occurred within 72
hours after a group of adults was dusted with 2c DDT. Absence of the writer
on extension and regulatory work prevented further records.

Insects Attacking Ornamentals

A LACEBUG (C6rythucha cydoniae (Fitch)).--This insect usually defoliates
several species of the ornamental shrub Pyracantha in Vississippi unless
controlled. On September 20, branches of Pyracantha well infested with
lacebugs were placed in beakers of water in the laboratory, the branches
drooping over large sheets of white paper to catch the insects which fell
as a result of the treatments, as it was practically impossible to count
the l]ve insects on the branches on account of the numbers of adults and
nymphs. In treatments 1 to 4, inclusive, some adults and nymphs had fallen
to the paper 6 hours after treatment and they continued to drop as time
progressed. A few dead nymphs were observed 10 hours after treatments
2 and 3 were applied. In the check, treatment 5, no insects were observed
*n the paper. The results 24 hours and 5 days after treatment were as

: After 24 hours : 5 days
Adults Nymphs :) Adults
No Treatment dead I dead alive

1 1% DDT dust 1 several 4
2 2 DDT dust 19 many 0
3% DDTdust 20 many 2
4 Spray, 1 lb. DDT per 100 gal. 11 some 4
5 Check-untreated 0 0 all

On September 21 a large, heavily infested shrub was dusted with 2?t
DT. Emination days later showed the numbers redwced but still
numerous on the twigs. By October 10 the shrub was aFain heavily infested
ind was dusted with 3% DDT. Examination 48 hours after the treatment showed
most lacebugs killed but a few specimens still on the plant. On October 25
very few lacebugs could be found on the treated plant but were very numer-
ous-several to the square inch-on the few leaves remaining on an untreated
plant 10 feet distant, which was almost defoliated by the bugs.

Clay Lyle

,' ....




\ ,"; ,' '
sa;n I


Ixperiments with DDT Conducted by State Agricultural
Experiment Stations, Agricultural Colleges,and Other
'Non-Federal Research Organizations


4 Vegetable Insects

Field tests for control of potato insect pests were planned in 1944 to
determine (1) the effectiveness of DDT-as a substitute for rotenone in com-
bating the tuber flea beetle, (2) the extent of tuber injury caused by the
11-spotted cucumber beetle, and (3) the effectiveness of undiluted calcium
arsenate and various fors of DDT in controlling the 11-spotted beetle. To
obtain this informaton, field plots at Corvallis were treated with:

1. Dust 0.5 rotenone, 20 percent calcium arsenate
2. Dust undiluted calcium arsenate
3. Dust 3 percent DDT
4. Dust same as No. 1 plus.bait spray of 10 percent barium
Sfluosilicate and.10 percent brown sugar
5. Dust same as No. 1 plus bait spray of 1 percent DDT and
S' 10 percent brown sugar

Two of M. B. McKay's fields at Corbet, Oreg., were used in a commercial
test to-compare 1-1/2 percent DDT dust with 0.5 rotenone in 20 percent cal-
cium arsenate dust. The potatoes grown by Alderman Farms at Dayton were.
used to test undil4ed 'calcum arsenate and 0.5 rotenone in pure calcium

As a result of these tests made possible on such a scale by the coopera-
tion of hese people, e can now recommend the use of.DDT on potatoes for the
control of the tuber flea beetle (Oreg. Exp. Sta. Cir, of Inf. #227)4 The
undiluted calcium arsehate or the straight calcium arsenate plus 0.5 rotenone
will also control the tubeflea beetle and are effective to a lesser extent
than 3 percent DDTdust on.the 11-spotted cucumber beetle. Atoiized oil con-
taiing 5 percent DDT is also effective in controlling both the! flea beetle
and the spotte beetle. The bait spray of DDT was more effective than that
containing the fluosilicate.

There can be no doubt that the larvae of the 11-spotted cucumber beetle
cause inuy to otat6 tubers. The injury is very similar to and in many
instance usas severe as that caused by the tuber flea beetle. Further
investigation must be conducted to determin te t correct timing of dust
applications forthe control of this pest.

K. W. Gray and Joe Schuh

CARROT RUST FLY.--An experiment at Woodburn, Oreg., in Aprill onsisted
6 treatments and 5 replicates on 30 randomized plts of arrts, each100
feet of row. One application of 3 percent Gesarol A-3 (Geigy Co.)
applied by knapsack duster at rate of 1/2 pound to 100-foot row, arr
were just showing through the soil and flies were present in the fiel
Reduction of injury was highly significant. Checks showing 55 percet w
carrots compared to 12 percent wormy carrots in DDT plots.

Symphylid--Experiment at Corvallis in May involved three vegetable ga
plots of 17 square feet, and six 1/10-acre bean plots. n the gardn
3 percent Gesarol A-3 dust (Geigy Co.) was broadcst and rototilled in t
soil at rate of 150, 220, and 370 pounds per acre. In the bean plots, 1/
pound of the dust and 5 ounces of seed per 40 feet of row were drilled i
the soil with a small hand seeder.

Results were as follows:
Vegetable garden-no appreciable reduction in Fopulation or red
tion in injury to plants .
Bean plots--overall reduction in population of 97 percent on the
DDT plots over the check. A corresponding increase in yield and
reduction in root injury.

Soil-Seed treatment of carrots-percent -injury

: 1 : 2 3 : 4:: 5 : 6 :: Total :.: Av. : Insecticide

1.: 0 : 0: 0 4: 4: 2 2:: 8 :: 1.3 I DDT

2.: 10: 10 : 8 18: : 8 :: 8 ::11.3 Halowax

3.: 4 : 6: 6 :10 :24 :22:: 72 ::12.0 apSulfur

4.. 8 : 16 8 26 : 12: :: 74 ::12.3 Dicorethyl
S: ::: : ether
5.: 16 :10 : 36 : 11 32 : 16 :: 121 20.2 Check

DDT Dusted -- 6 percent injury

H. E. Morrison

Psallus ancorifer Fieber (An onion seed plant bug) .--In early July in the
Willamette Valley, Gesarol A-3 dust (Geigy Co.) was applied with a bellows
hand type duster at rate of 35 pdunds per acre to a 25- by 50-foot plot O
onions raised for seed.

An infestation of 25'to 75 bugs per seed head was counted before the
dust was applied. Forty-eight hours after dust was applied there were no
live bugs in the dusted block. A number of dead bugs were found down deep

A~l:~~: .I . .. ,,,, .~1~,.: ,.~.~l:sl~, iE:~l~,,~ ~ .~.~

in some of the heads. The nfestation in the remainder of the field appeared
to be the same as on the date the dust was applied to the test plot--25 to 75
bugs per head-except for a few rows just east of the experimental plot. In
these rows there were very few live bugs and a number of dead ones.

B. G. Thompson

VARIOUS VEETABLE INSECTS.-At Corvallis, strawberries, asparagus, musk-
melons, mangels, onions, kale, broccoli, cabbage, eggplant squash, cucumber,
soybeans (Bansii), peas, lettuce, turnips, tomatoes, carrots, beets, corn,
beans, lima beans,* nd potatoes /4 acre-were treated for control of po-
tato flea beetle (Epitrix spp), cabbage flea beetles (Phyllotreta spp.),
1-spotted beetle, onion thrips, cabbage maggot and aphids, pea weevil, bean
aphid, and nitidulid. Eight applications of 5 percent DDT in light summer
spray oil-average bout 1/2 gallon per acre-were made by hand atomizer from
June 6 to August 1.

All insects appeared to be controlled except aphids on cole crops and
beans, and the cabbage maggots. The two-spotted mites increased in numbers.
This was the nearest insect-free garden until the mites moved in. There was
defiite burn on soybeans (Bansii) probably due to the oil. The kale was fed
to chickens from June throughout the summer, and it is still being fed, with
no apparent ill effects. All vegetables were consumed by the family and
others, with no ill effects. The only residue analysis was on the beans
(Blue Lake) at time they were canned. The residue was 1.87 milligrams DDT
per pound or 0.029 grains per pound.

K. W. Gray

Berry Insects

OBLIQUE-BANDED LEAF ROLLER.-At Gresham, Oreg., small plots and field tests
involving sme 250 acres of raspberries gave practically 99-percent control
of obliqe-banded leaf roller with no apparent damage to bees or other bene-
ficial insects. Insecticides tested were as follows:

(1.) 1-1/2 percent "DDT" dust, one application 2 weeks before
blossoming period.
(2.) Gesarol A-20, 2 pounds per 100 gallons, one application
2 weeks before blossoming period.
S(3.) 5 percent TDDTl in oil at ratio of 2 quarts per 100 gal-
lons. One application 2 weeks before blossoming period.

K. W.W. Gray and Joe Schuh

Fruit Insects

CHERRY FRITFLY.--In June at Corvallis one plot of about 25 cherry trees and
Ssecond plot of 8 scattered trees (isolated) were treated with 2 percent
and 3 percent DDT dusts with sulfur, talc, and diatomaceous earth as diluents,
used at the rate of 40 pounds to the acre-probably about 50 trees to the acre.
Application was with a power duster.

Results insofar as available:. .
A. 2 percent dust 2,476 chrries wee examinedand 3,356 larvae
Sfound. .
B. 3 percent dust (isolated orchard) 3,452 cherries examine& and
1,089 larvae were found.

S. C. Jones

PEAR THRIPS.--Gesarol A-20, 2# and 1#, with.2 pounds 'whale oil soap inech,
to 100 gallons of spray;'also Gesarol S 5 (GeigyCo.) t the rate of quart
and 2 quarts to 100 gallons'of"gpry, using from 4 to 5.gallons pertr
were applied in March with a powerer sprayerto 24-30 prune trees in eah.
4 plots at CorVallis against adult pear thrips. Based on the mort ty of
thrips in the buds 6 to 8 hours after spraying, heavy mortality in llof the
DDT plots. Numerous live thrips were found in DDT plots 2 to 6 daysafter

With a power duster, 2 percent and 3 percent DDT with sulfur, talc, and
diatomaceous earth, were applied at rate of 35 pounds per acre to 2 plots
about 10b prune trees per plot at Dallas. Application was made in May, at,
the beginning of shuck fall, against pear thrios larvae. Thrips population
on 300 leaves before dusting was 194. One day after dusting there were 28
on the foliage, and only 5 of these were still alive, where 3 percent dust
was used. With the 2 percent dust, on 300 leaves, 133 larvae were found
before dusting, and the day after dusting only 40 larvae were found on the
foliage, and all of them were dead except 9. Adjoining check plots .showed
127 and.139 larvae per 300 leaves a day after dusting. Of this number, 3
and 8 larvae, respectively, were dead.

At Corvallis, 16 plots of prunes, 9 square feet each way-8 treated and
8-untreated adjacent-were used to test 5 percent DDT in oil (Gesapon 18)
varied from 1 quart to 1 gallon in 100 gallons of spray, applied..on soil with
a sprinkling can in March to control pear thrips. Only 2 adults emerged from
the treated plots, while over 1,000 adult thrips emerged froam.the: djacent
untreated plots.

S. C. Jones

PEACH TWIG BORER (Anarsia lineatella Zell.).--At Corvallis .n May 12, Gesarol
A-20 at the rate of 2 po'unds in 100 gallons of water was applied by power
sprayer to one apricot tree. Apricots were about 1/2 inch in diameter. Se
of the apricots which were already falling from the .tree were infected with
Slive larvae. The owner reported that the apricots from the tree were always
wormy. This year the owner reports that at harvest he didn't find a single
apricot with a live worm in it. A few had dead worms in the cots. There
was no apparent injury to the tree, the spray operator, nor to those who con-
sumed the apricots. The owner is very enthusiastic over the results.

S. C. Jones

SNut Insects

FILBERT WORM.--In July treatments were applied with power duster and power
sprayer to 3 filbert orchards in the Willamette Valley. The form and dosage
of DDT was as follows:

Gesarol A-3 dust and A 20, 2 pounds in 100 gallons of spray. Rate 65
pounds per acre-70-96 trees--l0-12 gallons per tree.

Results were favorable, but slightly less effective than lead arsenate.
Infestation in nuts was slightly more than in the lead arsenate check.

nephasia lnaa (Haw.).-Gesarol A-3 dust, applied in May with a hand duster
to 120 newly planted filbert trees (1-1/2 acres) in the Willamette Valley,
gave practically 100-percent control.

B. G. Thompson


,L!ird31262 09238 7157

AP 7 ;;*
. . . . . . . . . . . . .l -""'"