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MASS. EXPERIMENT STATION BULLETIN 353 



their sides. The fall species can be distinguished from the spring species because 

 it has three pairs of abdominal legs near the posterior end, whereas the spring 

 species has only two. 



The pupa of the fall species is dark brown in color. The apex is rather blunt, 

 and the apical spine decurved and always forked. The spring species is more 

 sharply pointed and the apical spine is usually simple. The pupal cells, or cocoons, 

 of the fall species have more threads of silk than those of the spring species and 

 are not so easily broken. 



Life History. The moths of the fall cankerworm emerge from the ground 

 on warm days in the late fall and early winter. The wingless females climb up 

 trees and lay their eggs in regular clusters of about 100 on twigs and branches. 

 The eggs hatch about the time the leaves begin to show and the young cater- 

 pillars begin to eat holes in the \oung leaves, soon devouring everything but the 

 larger veins. When disturbed they drop on silken threads and maj- then be 



Cankerworms 



1. Fall cankerworm. a. Male moth IX. b. Female moth IX. c. Joints of female antenna. 

 Enlarged, d. Joints of female abdomen. Enlarged. 



2. Fall cankerworm. a, b. Egg, side and top views. Enlarged, c, d. Body joints of caterpillar, 

 side and top views. Enlarged, e. Egg mass IX. f. Mature caterpillar IX. g. Female 

 pupa IX. h. Anal tubercle of pupa, top view. Enlarged. 



3. Fall cankerworm egg mass on twig. Enlarged. Courtesy, Mich. Agr. Expt. Station. 



4. Spring cankerworm. a. Male moth IX. b. Female moth IX. c. Joints of female moth's 

 antenna. Enlarged, d. Joint of female moth's abdomen showing spines. Enlarged, e. Female 

 moth's ovipositor. Enlarged. 



5. Spring cankerworm. a. Mature larva IX. b. Egg. Enlarged, c, d. Joint of caterpillar's 

 body, side view and top view. Enlarged. 



Figs. 1, 2, 4, and 5, by C. V^ Riley. Courtesy, Missouri Dept. Agr. 



