86 SECOND ANNUAL REPORT OF 



The full grown larva (Figure 58, a) measures rather more than half an inch, and tapers a 

 little towards each end. It is of a sulphur-yellow color, with a transverse row of six velvety-black, 

 prickly tufts on each of the principle segments, the lower tufts being less distinct than those on 

 the buck. The first segment is entirely black with a yellow edge, while the spots on segments 11 and 12 

 usually run into one another. Head small, brown, and retractile, being usually hidden in the first 

 segment. Fine scattering hairs anteriorly, laterally »nd posteriorly. The young worm is of a 

 very pale yellow, covered with numerous fine white hairs, with a slight grayish-brown tint on the 

 head, and with the fifth and seventh segments paler than the rest, and having the black spots 

 scarcely visible. 



When full grown these worms disperse over the vines or forsake 

 them entirely, and each spins for itself a small, tough, whitish, flat- 

 tened cocoon (Fig. 58, c) within which, in about three days, it changes 

 to a chrysalis (Fig. 58, J), 0.30 inch long, broad, flattened and of a 

 light shiny yellowish-brown color. In about ten days afterwards the 

 moths (Fig. 58, e and d) begin to issue. This little moth is the Ameri- 

 can representative of the European Procris vitis; it is wholly of a 

 black color, except the collar, which is of a deep orange, and the 

 body ends in a broad fan-like notched tuft, especially in the male. 

 The wings are of a delicate texture, reminding one of crape, and when 

 the insect is at rest they generally form a perfect cross with the 

 body, the hind wings being completely hidden by the front ones, 

 which are stretched out straight at right angles, as in the genus Ptero- 

 phorus, to which belongs the Grape-vine Plume.* I have, however, 

 on one or two occasions found the American Procris resting in the 

 manner shown at Figure 58, d. 



This is the only Grape-vine feeding caterpillar which has a 

 gregarious habit, and as gregarious insects are always more easily 

 subdued than those of a solitary nature, the American Procris need 

 never become very destructive. Its natural food is undoubtedly the 

 wild grape-vines of our forests, and the Virginia Creeper, and Mr. 

 Jordon, of St. Louis, has noticed that while it very commonly attacks 

 the foliage of the Concord, yet it never touches the Clinton and Tay- 

 lor in his vineyard — a taste which is remarkable and not easily 

 accounted for, since the foliage of the latter kinds is more tender and 

 generally more subject to insect depredations than that of the 

 former. 



There are two broods of this insect each year with us, some of 

 the moths from the second brood of worms issuing in the fall, but the 

 greater part not leaving their cocoons till the following summer. 

 During the month of June they may be seen in pairs about the vines, 

 and I have also frequently observed around Hermann, a very closely 

 allied but smaller and different moth (Acoloithus falsarius, Clem.) 

 about the same season of the year. This last, though so closely re- 

 sembling the other, may be distinguished by being scarcely more 

 than half as large; by the body lacking the anal tuft and being 

 comparatively much thicker and shorter; by the hind wings being 

 comparatively larger, and by the collar being of a paler orange and 

 divided on the top by a black point. 



*First Rep., PI. II, Fig. 15. 



