1656 Insects. 



of fifteen months which it had passed in the caterpillar state. Forming its cocoon in 

 September, it lies, through the winter, in this state. Therefore the species requires 

 two full years for its progress through all its various changes ; whereas all the other 

 British species of the genus Lasiocampa pass usually through these changes in twelve 

 months." 



1. Lasiocampa Quercus, according to Donovan (British Insects, iii. 83 — 85), ap- 

 pears, in the winged state, in June, — according to Mr. Westwood in August. The 

 female deposits her ova in June or July ; the caterpillar is hatched in autumn, and 

 remains, during the winter, in this state. It feeds on Quercus robur, Prunus spinosa, 

 Crataegus oxyacantha, and divers herbaceous plants. All the successive skins as- 

 sumed by the animal in this state exhibit, from first to last, the same general colours 

 and markings. In the middle of May it spins a cocoon of a dull dirty straw colour, 

 and the perfect insect comes out in June or July, so that one year only is occupied in 

 its progress from the ovum to the imago state. The antenna of the male is very 

 strongly and distinctly pectinated, and consists of sixty-four minute articulated pieces, 

 the joints of which are nearly hidden by fine hairs, and measures, on the average, 

 three-eighths of an inch in length. The size of the insect is generally smaller, and 

 the colouring of the body, wings and antenna? less deep and rich, than those of the 

 species about to be described. 



2. Lasiocampa Callance. The perfect insect appears in June. The precise period 

 of deposition of the ova is unknown. The caterpillar is bred in July, and passes 

 through the first winter in that condition. Calluna vulgaris constitutes its principal 

 food. On every succeeding skin, except the last, the hairs investing it are so coloured 

 as to represent a series of circular ash-gray spots, arranged along the dorsal region of 

 the caterpillar, and increasing in size as the animal grows. From the last skin these 

 spots wholly disappear, and it then resembles, in colour and markings, the caterpillar 

 of the common species, and may be readily confounded with it by those who have had 

 no opportunity of observing the caterpillar in the successive stages of its development. 

 It passes into chrysalis invariably in September, and goes through the ensuing winter 

 and spring in that state, the cocoon being of a deep muddy-brown colour, so that two 

 entire years are consumed in the process of evolution. The antenna of the male is 

 more closely and delicately pectinated than in the preceding species ; it consists of 

 eighty-four pieces, not concealed by fine hairs, and measures full half an inch in 

 lejigth. The antenna of the female is also stronger and longer than in the female of 

 L. Quercus. The size of the insect is larger, and the prevailing colours deeper, than 

 in the first species ; and a rich glossy puce, not seen in that insect, is exhibited on the 

 wings of both sexes. 



It may, perhaps, be objected that L. Quercus sometimes passes a second winter in 

 chrysalis: this, however, constitutes the exception, not the rule. The same phenome- 

 non has occasionally been observed in our new species, and two — and even three — 

 winters have elapsed ere the insect has emerged from its cocoon. Size and colour, it 

 may, again, be argued, are very uncertain characters for the discrimination of species. 

 Taken by themselves they are certainly fallacious, but acquire considerable value when 

 invariably connected, as in the present instance, with other more solid and important 

 differences of structure and of habit. And I may fearlessly affirm, that many species 

 in the Animal Kingdom, universally acknowledged as distinct by zoologists, are 

 founded upon characters far less strongly marked and invariable than those distin- 

 guishing Lasiocampa Quercus from the new species which Mr. Weaver has had the 



