9 
infested twigs on which the caterpillars are grouped in colonies. 
They are particularly exposed to attack as they assemble in masses 
for their later molts, when a light spray of kerosene will readily 
kill them. They are also susceptible to arsenical poisons sprayed 
Fig. 6. Walnut Caterpillar, 2>a<a»at«<e9«rn»ia: A, moth; B, pupae. Natural size. 
(Kentucky Experiment Station.) 
