﻿Dec. 1895.] Dyar and Morton. New York Slug Caterpillars. 153 



as we will show to be the case with Sibine and Eulimacodes, but in the 

 northern temperate regions of both the old and new worlds. 



The larvae of the nearest American allies of A. y-inversa (A. recti- 

 linea and A. biguftata*) are unknown. It differs as follows from Tor- 

 tricidia fasclola, which is the only larva at present known at all resem- 

 bling it : More elongate, less shortly rounded than fasciola ; sides less 

 concave, the tail the same. Color much less transparent, not the clear 

 yellowish green, but whitish, opaque. Depressed spots blurred in the 

 whitish ground, not indicated by broad pale yellow rings. Sel£e ob- 

 solete in both, but the skin o{ fasciola is more coarsely and irregu- 

 larly granular, the incisures marked, cleft-like, while they are obscure 

 m y-inversa. The subdorsal line is distinctly bordered above by a dark 

 shade, whereas in fasciola there is no other color than the yellowish 

 green and yellow. 



The eggs are laid singly, and the larvae after hatching eat only the 

 parenchyma of the leaf for the first two feeding stages. The manner of 

 feeding is characteristic of the species. Y-inversa feeds in a track on the 

 upper side of the leaflet the width of its body. (Plate VI. fig. 19, stage 

 II ; fig. 1 3, stage III.). In the fourth stage and after it eats the whole leaf 

 (Plate VI. fig. 16, 17). At New Windsor, the larva has been found 

 only on the species of hickory ; it has occurred on hickory in Van 

 Cortlandt Park, New York City, and near Glendale, L. I.; Dr. Thax- 

 ter also reports it on this food-plant. The larva described by Mr. Dyar 

 was found on oak, but the identification is not positive as y-inversa. 



The larva o{ y-inversa seems to be not commonly found. At New 

 Windsor a few are occasionally taken in the bags placed on the growing 

 trees for the confinement of other hickory feeding larvae. Near New 

 York City the larvae occur mostly on low hickory shrubs, always singly. 

 They are subject to the attacks of a number of parasites in consequence 

 of which their numbers are greatly diminished. 



There is but a single brood during the year. The moths (Plate 

 VI, fig. 9) fly during the first half of July. The males seek their mates 

 soon after dark, between half past eight and nine o'clock, flying with 

 unerring instinct directly to that part of the cage where the female is 

 clinging. After pairing the moths remain in coitii until about the same 

 time the next evening. The females immediately after begin to lay their 

 eggs, and continue night after night until all are laid. 



The mature larvae may be found early in September, making a 

 period of about two months to complete the seven larval stages. 



* We believe the identification of this larva by Dr. Packard (5th Report, U. 

 S. Ent. Com. p. 147) to be founded upon error. 



