Pomona College Journal or Entomology 567 



Arsilonche Lederer 



Moderately stout species, resembling Leucania, with fine hairy vestiture, 

 rather narrow, somewhat pointed primaries which bear no trace of transverse 

 maculation. The head is not so large as in Acronycta, yet scarcely retracted, and 

 the eyes are of good size. Tongue weak, not used for feeding, palpi small, 

 antennae simple in both sexes. Thoracic vestiture close, forming no tufts. 



The only Californian species is A. albovenosa Goeze, which occurs throughout 

 Europe and the United States. In color the wings are very pale luteous gray, 

 fading to almost white, the veins are whitish, margined with slate gray, the 

 intervening spaces of the ground color. A more prominent slate-gray streak runs 

 through the sub-median interspace from the base, fading out toward the margin, 

 another starts in the median cell and widens outwardly, becoming diffuse. The 

 secondaries are white or whitish, and the species average an expanse of 1.50 inches. 



There is considerable variation in the depth of ground and in the relative 

 distinctness of the longitudinal markings ; but the general appearance of the insect 

 is remarkably constant. 



The larvEe is said to feed on grasses, smartweed and willow. It is an early 

 species and California examples are dated from January to March. 



The American form was described as distinct by Grote, as A. henrici, but 

 practically every student who has compared series from the European and 

 American faunal districts in early and adult stages has united the two. In his 

 recent catalogue Hampson again separates them, differentiating the American 

 form by the somewhat more acutely produced primaries, while the streaks and 

 irroations are said to be bright red-brown as against darker brown for the 

 European form. Neither of these characters is constant although, as a rule, the 

 European specimens are more dull in appearance — in which respect this species 

 agrees with most others which are common to both countries. In the east the 

 larvffi sometimes appear in very large numbers, although scarcely as an economic- 

 ally important species. 



