I DE 
IDE dust was one of tl als used 
ainst tl .ment 1 of 1950 (table 3). It was inferior 
to .me dust, and c aused moderate chlorosis of cucumber 
foi 
soprop) I Pj :• ohosphate 
lisopropyl pyrophosphate dust was of no apparent 
value against the pi< kl-worm in experiment 1 of 1949 (table 3), and 
gave only 53 -p< »n of th< onworm in tl ar. 1 
ed no not iant injur . 
Effect of Zineb on th< I .vorm 
During the 1950 studies considerable evidence was obtained to sub- 
stantiate the observations of Genung (12) that the fungicide zineb is 
moderately toxic to the | worm. The unusually low pickleworm 
Station on cucumbers in the Charleston, S.C., area in the fall of 
that year was attributed at least partly to the extensive use, for the first 
time, of for disease control. Additional evidence of the tc of 
zineb to the pickleworm was obtained i . eral laboratory cage tests 
and a small-s« -Id-plot experiment on squash (Reid 18). 
[n experiment 3 of 1951 (table 3) two 4-percent zineb dusts prepared 
from dif: ercial brands of that fill le significantly reduced 
the number of pickleworm -infested cucumbers, but did no: quate 
protection. Both dusts caused si hlorosis of the foliage and also a 
significant increase in the melon aphid population (table 
Th- trol of the pit h i m with si pron 
195 taking possil thai inse> dos- 
s of lii »ed, tl r of 
lue, off-i ' I ■ • I 
ilent ; i rs 
pickleworm lnf< 51 
anied by weekly appli 
plantinj 
pp] Led .i week I the I 
aln 
A dust containinj en1 
ethi teatii 
ethrum 
