56 Maine Agricultural Experiment Station. 1917. 



length twice that of the spiracles ; spiracles usually black or 

 dark brown and produced for a distance equal to their length; 

 a prominent projection usually present on each side of the anal 

 opening, probably the scars of the anal prolegs ; cremaster less 

 than 1 mm. in length, usually triangular at base narrowing ra- 

 pidly so that the distal end is cylindrical and spine-like, slightly 

 bifurcate at tip ; lateral setae of the cremaster very fine and 

 easily broken and not usually found on specimens. 



Average length 8 mm.; greatest width 3.5 mm.; height at 

 third abdominal segment 3 to 3.5 mm. 



The larvae of the spring canker-worm are about an inch 

 long and vary considerably in color from light brown to dull 

 black. There is a yellow stripe running through the spiracles 

 and a greenish yellow stripe underneath. They are ready to 

 pupate about the first of June and enter the ground where they 

 make an earthen cell and change to pupae. They live over win- 

 ter in the pupal stage, the moths emerging in early spring. Al- 

 though the female moths of this species are wingless, the pupae 

 have the wings as well developed in the female as in the male. 



Genus ERANNIS Hiibner. 



Cephalic half of body much thicker than the remainder, the 

 dorsum of the first three segments convex as seen in lateral 

 view ; f ronto-clypeal suture distinct for a part of its distance ; 

 clypeal and labral regions distinctly elevated, the labrum almost 

 semi-circular in outline ; labial palpi not visible ; maxillae never 

 quite reaching the caudal margin of the wings, the proximo- 

 lateral angles never reaching the eye-pieces ; antennae consider- 

 ably broader than the prothoracic legs and only slightly nar- 

 rowed at the distal end, always reaching the caudal margin of 

 the wings and there curving mesad and normally touching; pro- 

 thoracic legs at least seven-eighths the length of the wings, the 

 femora never exposed, the cephalic end extending between the 

 antenna and the sculptured eye-piece; mesothoracic legs as long 

 as the maxillae and almost reaching the caudal margin of the 

 wings ; prothorax one-half the length of the mesothorax, the 

 caudal margin not prominently curved at the meson; mesothor- 

 acic spiracles with a prominent ovate flattened tubercle adjacent 

 to its caudal margin, the surface rugose and apparently cov- 

 ered with very fine, short setae, the tubercle extending at least 



