72 



NEW YORK STATE MUSEUM 



on the vein tips. The very long, black flecked labial palpi are 

 most characteristic of the insect. It is the form which was largely 



responsible for the extensive 

 outbreak in the St Lawrence 

 valley recorded above and is 

 probably fully as destructive 

 to grass in this section as any 

 Crambid. 

 Description of early stages. 



Fi^.. Craxnbus vt^rgi vagellus. enlarged ^hc moths fly aboUt dusk dur- 



(Origmai) jj^g ^j^^ latter part oi August 



and the first half of September and are attracted to light in large 

 numbers, though a considerable proportion of the captures are males. 



The pale straw-colored eggs turn to a reddish buff color before 

 hatching. The very young larva is only about -gV ii^ch long and 

 has a dark brown head, an olive-colored thoracic shield and a 

 straw-yellow body. Late in the fall the young caterpillar may be 

 nearly ^ inch long. The head is then jet-black, the thoracic shield 

 a deep brown and the brown body ornamented with dark brown 

 hairy tubercles. The full grown larva (presumably this species) 

 is about ^ inch long with a very dark brown almost jet-black head.- 

 The thoracic shield is dark brown, shining and the body a dull 

 reddish brown or olivaceous with well developed, dark brown 

 tubercles, each bearing a moderately long, stiff, brown hair. The 

 thorax and abdomen are a little wider than the head, the latter 

 being broadest near the middle, tapering somewhat toward the 

 posterior extremity. Anal shield well developed, variably dark 

 brown. True legs dark brown, prolegs dark brown, olivaceous. 

 Ventral surface light yellowish brown. 



Life history. The moths fly more or less during the day, par- 

 ticularly in shady places. The females are quite prolific, one 

 depositing 320 eggs after capture, which is probably about the 

 normal number. The young larvae remain for a time coiled up 

 on a leaf in plain sight when not feeding, and if disturbed lie quiet 

 for a minute and then try to escape, or they may drop at once by 

 a silken thread. The larvae feed mostly during the day as cold 

 weather comes on and occasionally may be seen eating in the early 

 morning. They devour the soft parenchyma at first and later the 

 whole leaf is consumed. This species feeds mostly on grass though 

 it eats small grains, and winters as an immature larva which 

 resumes feeding in the spring, completes its growth the latter part 



