74 



BRITISH BUTTERFLIES. 



examination of the eggs in September showed the fully-developed 

 larvae curled up within the eggshells, that they remained thus, at 

 Berlin, till the end of February and early March, by the 10th of 

 which month all had hatched. Buckler observes (Larvae, etc., i., 

 p. 113), that some eggs of Plebeius aegon, obtained in the summer 

 of 1867, were found to contain living larvae in February, and that 

 these hatched at various dates from February 28th well on into April, 

 1868. Lyman notes (Can. Ent., 1902, p. 127) that the Nearctic 

 Plebeius scudderii laid eggs between July 23rd-80th, 1899, that the 

 larva? remained in the eggshell until the end of April, 1900, so that its 

 habit is almost identical with tbat of P. aegon. 



Among the "blues" the habit of producing "forwards," in some 

 species, is extremely developed, especially in tropical and subtropical 

 countries, but, as may be expected, in a family with such a world-wide 

 range, the habits are exceedingly diverse, varying even in the same 

 species, in this particular, according to latitude, altitude, etc. Among 

 our European species, Lycaena avion appears to be absolutely single- 

 brooded, and so, in central Europe, is Agviades covydon, yet, in a few 

 w T arm spots on the Mediterranean littoral — Hyeres, Ste Maxime, etc. — 

 the whole of the eggs of the first brood appear to produce " forward " 

 larvae and the species becomes double-brooded. Almost all our British 

 species produce some " forward " larvae, and hence are double-brooded, 

 or partially so, and, in really suitable seasons, the summer examples in 

 their turn may produce " forwards " and thus initiate a partial third 

 brood. Such is the case with Celastvina avgiolus, whose broods are 

 dealt with at length in the systematic part of our work. The broods 

 of Eveves avgiades are very similar, a large percentage of the larvae 

 resulting from the spring emergences going " forward," whilst the 

 imagines resulting from these also occasionally produce larvae that 

 go on to a third emergence in southern Europe. The American 

 form, comyntas, is said by Scudder to produce " forwards " developing 

 into a second brood in the Northern States, and these ae'ain " forwards," 

 making a third brood in the Southern States. Edwards notes 

 (Can. Ent., viii., pp. 202 -3) that the forward larvae of comyntas feed up 

 very rapidly — eggs laid July 9th, 1876, hatched July 12th, first larval 

 moult on the 15th, second moult 18th, the third moult 21st, the fourth 

 26th, pupated July 31st, imago emerged August 9th. Through southern 

 and central Europe Polyommatus icavus, Cyanivis semiavgus, and 

 Agviades bellavg us, produce many "forwards," and are largely double- 

 or partially triple-brooded, but, in some unfavourable seasons — e.g., 1888, 



1906, etc. — in Britain, A. bellavgus larvae resulting from the first brood 

 go into hybernation early, and scarcely a "forward " results. The typical 

 form of Avicia astvavche produces "forwards" freely in most parts of 

 southern and central Europe, but, in the higher latitudes and altitudes 

 that it inhabits, fails entirely to do so, and Harrison observes (Ent, 

 Rec, xvii., p. 268), that larvae from Durham and Fife "resolutely 

 refuse to feed up the same year, even in a hothouse," so completely 

 has the forward habit been eliminated in Scotland and the north of 

 England. Bayward also notes (in. lift.) that the larvae from a large 

 batch of ova of P. icavus laid by a Cornish £ at the end of June, 



1907, all prepared for hybernation early in August, in the third instar, 

 and could not be tempted to continue feeding although kept in a warm 

 room. Prideaux observes {in litt.) that, on two separate occasions, 

 larvae, from eggs laid by the first brood $ s of P. icarus, fed on Ononis, 



