98 INJURIOUS INSECTS OF KANSAS. 



WALNUT MOTH. 

 (Datana angusii G. & R.; Order, Lepidoptera.) 



Diagnosis. Infesting walnut and hickory; large, blackish cat- 

 erpillars, feeding on the leaves; often large numbers, moulting, 

 gathered in a mass or ball on the trunk or on large limbs ; when 

 feeding, remaining close together and entirely defoliating portions 

 of the tree, often whole trees. 



Description and Life-history. The adult is a light-brown moth, 

 with chestnut-brown head. There are several transverse, brown 

 lines on the fore wings; the hind wings pale yellowish, unmarked. 

 Expanse of wings about two inches. 



The insect hibernates in the pupal stage in the ground. The 

 moths emerge in June, and lay their eggs on the under surface of 

 the walnut leaves. The larvae, after hatching, keep together and 







FIG. 54. YELLOW-NECKED APPLE-TBEE CATEBPILLAB (Datana ministra), closely allied 

 to, and greatly resembling, the Walnut Moth (Datana angusii); a, larva; 6, mothi 

 c, eggs; d, an egg, greatly enlarged. 



feed voraciously. They rapidly defoliate branches, and attract 

 attention in this way. When ready to moult, they migrate in a 

 body to some spot on the tree trunk, or on some large limb, and 

 remain there in a solid, wriggling mass, until the skins have been 

 cast. Returning to the leaves, they continue feeding. When 

 full-grown, which they become in about five weeks, the caterpil- 

 lar is entirely black, with scattering, long, whitish, wooly hairs 

 over the body. When younger the color is rather wine-red. The 

 larvse descend from the tree at about the same time, and enter 

 the ground, where they transform into naked, brown chrysalids. 

 The moths emerge the following May or June. 



Remedies.- Spraying the trees with London purple (see p. 8) 



