72 ZYGiENID^ AND BOMBYCID^ 



hairs, mingled with black along the sides, and a few rusty hairs on the 

 segment, (anal, pi, lo, fig. i.) It feeds on the various species of lupin, 

 is full fed about the middle of July, and spins an irregular, thin open 

 cocoon, composed entirely of white silk without intermixture of the 

 hairs from the body. The imago appears in August and flies readily 

 in the day time. Its flight is strong and rapid, making it a difficult 

 insect to take on the wing. 



This species is abundant in the neighborhood of San Francisco, 

 (though extremely subject to the attacks of ichneumons of a variety of 

 species) and also at Washoe Valley in the State of Nevada; probably 

 also in many other localities where its favorite food-plants are found. 

 It is liable to many variations, as is the case with many species of this 

 sub-family. I have given E. guttata as a synonym after careful exam- 

 ination of a large number of specimens, being unable to draw the line 

 of distinction. They have been separated on the differences of color- 

 ation of the posterior wings, yet in a long series it is possible to find 

 specimens of every intermediate gradation of color, while if extreme 

 types are selected, there ought to be three instead of only two species. 

 The specimen figured on plate 6 of vol. i of the Trans. Am. Ent. Soc. 

 is evidently the intermediate form, in which the fulvous and black of 

 the lower wings are nearly equally divided, the abdomen being black 

 above, with traces of fulvous bands across the sides. This may be 

 considered the type, although Boisduval appears to have had before 

 him, when he drew his description, the second variety, in which the 

 fulvous coloration largely predominates, the black being much reduced 

 in area, and the abdomen banded above with fulvous, thus giving the 

 insect a paler and distinct appearance. The third variety ( E. guttata) 

 has the lower wings almost entirely black, only a few small spots re- 

 maining of the fulvous coloring. 



Now from larvas collected on the same spot and at the same time, I 

 have raised both 5 and ? of varieties i and 2, without being able to de- 

 tect any differences in the larvce, and my friend Henry Edwards, of San 

 Francisco, has collected varieties i, 2 and 3 in Nevada, on the same 

 ground and at the same time, and assures me that he has never been 

 able to detect more than one type of larva on the locality where these 

 were taken. It follows then, that while the absolute identity of varieties 2 

 and 3 is not yet fully established, the fact is proven as regards i and 2, 

 which differ equally widely, and all the evidence is in favor of their be- 

 ing merely varieties of the same insect. The gradation of coloration is in 

 favor of this view, although it is by no means difficult to segregate a num- 

 ber of specimens into the respective varieties with tolerable certainty. 



