448 BRITISH LEPIDOPTERA. 



The peculiarities cited concerning the life-histories of L. quereus and 

 callunae are still more complicated in the case of T. crataegi and ariae, 

 for the larva? of both the first-named forms hybernate once as larvae, the 

 callunae form having developed the power to hybernate a second time as a 

 pupa, but the normal T. crataegi hybernates as an egg, feeds up rapidly 

 in spring, pupates in June, and emerges in August and September, whilst 

 according to Schneider, ariae hybernates first as a quite small larva, is 

 full-fed in July or August, hybernates a second year as pupa, the 

 imago appearing the next June. This is so entirely different from the 

 normal habits of T. crataegi (and the hybernating habit of many species 

 is so constant) that one is at first somewhat astonished at an insect 

 that can hybernate as egg, larva, and pupa, and emerge at an earlier 

 period of the year than the typical form of the same species. One can 

 understand at once, that ariae is absolutely isolated by its time of 

 appearance, habits, and habitat, from the type, and must sooner or 

 later become a species apart. P. populi, that normally hybernates as 

 an egg, is stated by Sharp to have its pupal stage prolonged for several 

 years, whilst P. trifolii which is stated by most continental authorities 

 to hybernate as a young larva, hybernates in Britain as an egg, 

 although the larva is fully formed all the winter within the shell, and only 

 awaits the early spring to gnaw its way out. Most of the species can 

 pass a second winter as pupa, but L. lanestris is, far excellence, superior 

 to all others in this respect. 



Lachneis lanestris is on the wing in Britain in February, its habit 

 of going over several years in the pupal stage is very remarkable, and 

 a period of seven years has been recorded before the living pupa gave 

 up its imago, three, four, and five years, form not at all an unusual 

 period, and the imago always emerges true to its own particular time. 

 Gastropacha ilicifolia is a very rare species in Britain, found in moor- 

 land districts, the imago appearing in late April and May ; Macro- 

 thylacia rubi also appears in May, as does L. quereus var. callunae 

 continuing, however, through June ; in July, typical Lasiocampa querciis, 

 Malacosoma castrensis, ill. neustria, Cosmotriche potatoria and Eutricha 

 quercifolia are on the wing, and last well into August. In the latter 

 month, Pachygastria trifolii, a very local insect, appears in the New 

 Forest and in various coast localities, whilst Trichiura crataegi, appear- 

 ing in August, lasts well into September ; Poecilocampa jwpuli, more 

 often appears in November and December, but the coldest January 

 does not prevent the late specimens from emerging, and they may 

 sometimes be found, with the temperature far below freezing point, 

 clinging to the gas-lamps, for, like almost all Lachneids, light has a fatal 

 attraction for this species ; it has also been found frozen stiff, and 

 embedded in ice, but has recovered after being brought into a warm 

 room. Most of these species are well distributed and common. We 

 captured all except G. ilicifolia, M. castrensis (which abounds on the 

 marshes of Essex and Kent bordering the Thames), and P. trifolii, the 

 first year we systematically collected insects ; still L. lanestris, T. 

 crataegi, E. quercifolia, and P. populi are species not to be found 

 without careful search in many districts. 



It would appear that the correct name for this superfamily is 

 Lachneides and not Lasiocampides by which it has been recently 

 pretty generally known. Historically the superfamily seems to have 

 been eliminated somewhat as follows : Linne included it in the 



