500 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1925 



From the frequent occurrence of bare oval patches in aphid 

 colonies inhabited by these caterpillars and the fact that when 

 fully grown they curl up and drop at the slightest touch, while if 

 aphids are abundant they are never found, in my experience at 

 least, except in aphid colonies, I feel sure that the normal habit of 

 the caterpillars on reaching full size is to drop to the ground and 

 to pupate on any convenient support. 



I have found two pupal skins from which the butterflies had 

 emerged. One of these, in Newtonville, was about 4 feet up on 

 the main trunk of a large alder which had no aphids on its 

 branches; the trunk was about 3 inches in diameter. The head of 

 the pupa was directed downward. The other, from Essex very 

 near the Manchester line, was on the upper side of an alder leaf 

 about a foot from the ground and directly beneath a large colony 

 of aphids about 6 feet above it. The leaf was smeared with the 

 exudations from the aphids to which cast skins and " wool " ad- 

 hered. The pupa was in the inner half of the leaf and was at- 

 tached to one of the veins near the midrib; its axis was parallel 

 to the vein and its head was directed outward toward the margin 

 of the leaf. In both these cases the larvae had evidently dropped 

 and thence crawled up to the supports on which they were found. 



My experience with a dozen or so caterpillars that escaped in 

 the house was quite similar to that of Misses Soule and Eliot. 

 They pupated anywhere, one behind a picture 6 feet from the 

 floor; but the favorite place was on the mop board or on chair 

 or table legs from 2 to 6 indies from the floor. 



As described by Mr. Scudder the chrysalis is pallid-green be- 

 neath, flecked with minute brown dots on the wings, legs, and 

 tongue, but not on the antennse, and hardly at all on the abdomen, 

 excepting laterally. The head and prothorax are pallid, the former 

 flecked with blackish, and the latter with many brownish flecks 

 next to the posterior margin. The rest of the thorax is dark 

 greenish-brown above, irregularly blotched and flecked with cream- 

 yellow, most conspicuously at the summit and down the interior 

 base of the wings. The rest of the wings is pallid-green, minutely 

 flecked with brown. The abdomen is also dark greenish-brown, 

 the first two segments darker than the rest and deepening to black 

 laterall}^ next to the wings, the whole irregularly flecked above 

 with cream-yellow, giving a minutely mottled appearance, and at 

 the sides of the globose portion and on the top of the expanding 

 tip predominating; particularly the lower half of the sides of the 

 fourth abdominal segment are almost wholly cream-yellow, and 

 those of the sixth and seventh heavily blotched with pfceous. There 

 is a lateral series of short oblique black bars in the middle of the 



