FAMILY HABITS IN BUTTERFLY LARVAE THE EURALIDS. 65 



freely, it is almost impossible to find them by searching. The larvae 

 of some of the Nearctic Strymonid species, e.g., those described as 

 Thecla liparops, T. calanus, T. edwardsii, and T. acadica, by Scudder, have 

 very similar habits. This author says that T. liparops, when quite young, 

 eats holes through the leaf, and afterwards eats holes or bites the edges 

 indifferently; when nearly full-grown and eating, the prothorax covers 

 the head and edge of leaf so that one cannot see the operation, whilst 

 the larva itself is very inactive. Of the larva of T. calanus also he 

 observes that it eats holes in the leaves of its foodplant, not touching the 

 edge, that it is slow in its movements, differing considerably in this respect 

 from that of T. edwardsii, which, Scudder says, walks with considerable 

 rapidity, in marked distinction from the sluggishness of allied species, 

 although it eats small holes in the leaves of oak in quite approvedStrymonid 

 fashion ; T. acadica larva, however, feeds on leaves, eating from the edge 

 onward ; this larva is noted as very supple in its movements, the body 

 curving like that of a snail, whilst its movements are slow. Just as 

 the larva of S. pruni, in its food-habit, is restricted to blackthorn and 

 plum, and E. w -album to elm, so T. acadica is confined to willow of 

 various species, T. edwardsii to oak, T. calanus also to oak, but 

 T. liparops is said to be almost polyphagous, although the evidence 

 (Butts. New Eng., p. 882), is not at all convincing. Lintner states 

 (Rept. Ins. New York, iv., p. 137), that he found the larvae of this 

 species burrowing into cultivated plums, and eating out their interior 

 much as Incisalia irus (henrici, see antea, p. 63) does. This certainly is 

 a most unusual habit for a Strymonid larva. 



Like the Palaearctic Strymonids, the Nearctic species rarely pro- 

 duce " forward " larvae. They have not been observed in T. liparops, T. 

 edwardsii, or T. acadica, whilst the larvae of T. calanus are noted as 

 feeding up at very different rates, according to latitude, being fullfed 

 in April in the southern States, from May to July in the middle and 

 northern States, whilst even August is not too late for the larva in its 

 most northern habitats, yet, even in the southern parts of its range, it 

 is never double-brooded. All the larvae of these Nearctic species, too, 

 pass the winter inside the egg, not hatching therefrom till the early 

 spring, although fully developed some months before they leave the 



egg- 



The Strymonid larvae are markedly cannibalistic in their habits. 



The way in which the larvae of Edwardsia w-album will attack other 



larvae of their own species as soon as they have settled down for 



pupation has often been noted. Scudder states (Butts. New Eng., p. 



890) that the larvae of Thecla calanus is a cannibal, eating its weaker 



brethren when short of food. 



Our ignorance of the larval habits of the species forming the large tribe 



Pairalidi, is colossal, and our knowledge appears to be confined to our 



two Palaearctic species, Bithys querciis and Ruralis betulae. The larvae of 



these two species agree pretty closely, in their habits, with those of the 



Strymonids. They have the same winter-habit of hybernating within 



the eggshell, the same tree-feeding habit, the same slow gliding 



movement, the same habit of resting by day and gaining protection 



by the similarity of their colour and markings to their surroundings, 



the same external-feeding habit, etc. The larva of Bithys querciis is 



particularly Strymonid in its habits ; when young it buries its head 



and neck into the felt on the young oak-leaves, clearing out the 



