season, was estimated. This was done b determinin it ave the best kill of a lrids and cucumber beetles;
Y 3 P
the number of worms acquired by worrn-free calves the poor yield in 1954 was the result of severe burning
8 which were allowed to graze for short periods of time and stunting of the plants by the 2.5 percent chlor-
Q at appropriate intervals with each of the test groups. thion dust. Because of toxicity to the plants, the ·
·1• A summary of the observations for the year shows chlorthion dust was reduced in concentration, and in
I that the treated animals ac uired onl one—third to one treatment the 1.5 ercent chlorthion dust was
A (1 Y P
· one-half as many worms as the untreated or control put on after the first three dustings were made with
  group. In addition, the treated animals made con- 3 percent purified DDT.
R sistently greater weight gains which indicated bene- Weight Of fruit % Difference In
5, ficial action from medication in the treated group. 195·’$f¢‘¢<1¢m¢¤¤fS i¤0¤¢¤C€S ffvm Check
. . , . · · · 1.5% Chlorthion dust .................. 947 — 4
, Although these results eI1€·1`|Ot conclusive, surprisingly 3% Purified DDT dust   17551 + 57
high levels of worm infection were found. More data :3% Purified DDT dust and
E ·. , as · . · 1.5‘7 Chlorthion dust .............. 1,168 —l- 18
on. this problem are being accumulated by repeating O·45%°PuriHCd DDT spray   17549 + 57
, this study during the present Season. 0.16% Endrin spray ...................... 1,625 + 66
···: 0.16% Lindane spray .................... 1,122 + 14
Untreated check ............................ 988 __,_ I
e Cucumber Insect The . _ . . . .
· plots receiving the lrndane and endrin dusts
1       yielded less than that receiving the DDT dust. On
g the other hand, the lindane and endrin dusts con-
. . t·olled aalrds o‘e effe t` el tl; tl e DDT l t
=1 Pests mclude striped and ‘_ I I III I, YC IY° I IIII I“ . ‘“S ’
although not so eflectrvely as the chlortlnon dusts.
* SP0tt€(I b€€tl€Ss {163% b€€tl€S¤ The plot sprayed with endrin outyielded that sprayed
‘* aphids and pjcklg WQTHIS with DDT. The lindane spray burned and stunted
` · the young plants, resulting in lowered yields. There
RY RICHARD THURSTON was no difference in yield between the plots sprayed
ii y p p _ _ p p `. or dusted with purified DDT.
A _Imé° _IIIIIIIb€I OI IIIWCI8 ‘Itt‘ICk Cucumbu I)I‘uIt§’ Because many of the insecticides effective against
or starting with the planting of the seed and continuing insects ,ltt_1CkiuU Cucurbits UG ,1150 Very mjurious to
.4 through the harvest period. For this reason a regular Some CuCm_bitS°H(_1d ind hbm__1tOl_y tcgts wom com
,5 WGQIIIY IIIS“’II?I‘I;II SCIIGIIIIIEfISHII€‘I€SSf§Y IO §I`O"I'1E’1II` ducted during the past two years to discover some
°IIIII IEIS OI PI° L5 5I;°°°“*_II I1 ml UIIUCI y' I6 of the factors contributing to tlns toxicity towards
EPI? IIIT"°I}II“IE IIT I Ii *IIIPiI_ {IIII spite; °II°IIIIIf plots. Several insecticidal dnsts were applied to seed- ·
°I €°I“» IIII _°‘I IGGI eh IPIII5 ‘IIII_PI° ° “'°IIII* ling cucurbits in 1954. The niost toxic materials in
we IIIFl"€I`1i °I“SII`IgCI3"€ IB ‘°III_€ *II`“IS “{III III SIIIIIG Y§*II`“· descending order of toxicity were 3 percent chlortliion,
I} ‘f}IIOIIgI $IIIIl°( 5)     [$0Of PIOICIIIOII {III? 2 percent chlorthion and 4 percent malathion. The
1 II€l°II°IIIII IGI IFII GS» II Ii IIEG érffve ‘Ig‘IIII“I EIPIII ’ following materials caused no plant burning: 3 per-
‘IIIi   IIIIYIIII CIIIIIIII II Em €“’;IIIIIS·f _ H cent purified DDT, 1.5 percent lindane, 1.5 endrin,
I r II 10 III iuséb W°I° HSI; {III EOIS OE PIf‘lIIIg and 2.5 percent heptachlor. A negligible amount of
CIICIIIII wl? at I I6 *lI°IIIII°III IIIIOII aI_III' ac I ( IISI burning resulted from 1 percent chlorthion and 1 per-
6. was applied at weekly intervals, starting when the CGM P,u_,1thi(m All the Vwietieq Of Cucumbcrs {md
3. S?€‘I_IIIIgS1""`I`°lIIIi“II‘IIIg IIII"IIIgII IIIQ gI`OIIII‘I fIII‘I CO"' bnttercnp, scallop, crookneck, lrnblrard and cnsliaw
* IIIIIIIIIf‘* III‘IIIgI I‘IIV€bI‘ squashes were badly burned by the most toxic ma-
1VQis’h¢ of fruit % Diffwmlcc terials, but the zucchini squash, cantaloupe and water-
5 1954 dns! Iiezilirzerrls tn ounces from check I _ _ I I _ f_ f_ . . _ {_
3% Pmmcd DDT   2384 + 32 me on were tl most ree rom rn]ury rom any of the
1.5% Endrin .................................. 2,3453 + So dusts. Other field and laboratory tests with chlorthion
w '!     ································     and malathion dusts and sprays showed that seedling
..4.r O ........ ...... ....... ............. ..4, ( · · l .
Q, 4% Malathionl ................r............... 1,779 — 2 cucumber plants were more susceptible to insecticrdal
,   injury than plants that had started to vine; that wet
5 Untrcatcd check ............................ 1,809 .... '_ A _ ,. _ . _ . . _
————  plants were more easily burned by insecticides than
* In 1955 the more effective insecticides were tested dry ones; and that activated carbon added to the spray
a rain but several of them were used as s rravs instead material could eliminate or reduce the rhvtotoxicitv
fp 1 . _ 1 . .
* of dusts. The chlorthion dust was used again because of chlorthion.
I W -..
_ KrsN’rUcr