ANTHBOCERA. 417 



tion. Many larvas that commence feeding in the spring eat only for a 

 short time, and then asstivate and hybernate again for a full year, 

 feeding up the next year. Boisduval says that three changes of skin 

 only occur in the spring. This also can only be true for a limited 

 number of species. 



When the larvae of A. trifohi, A. filipendvlae and their allies 

 are ready to hybernate, they spin a silken pad, on which they moult 

 before hybernation. At the same time they lose their green tint and 

 become of a sandy hue. The larvae feed in the spring before moulting 

 again. The moulting of the Anthrocerid larva is peculiar. It is not 

 effected by creeping out of the old skin through an aperture made in 

 the thoracic segments or head, but the larva simply remains quite still, 

 whilst the skin bursts open mediodorsally the whole length of the 

 back. 



The food-plants of the larvaa of this genus consist almost entirely 

 of herbaceous leguminous plants Vicia, Coronilla, Lotus, Hippocrepis, 

 Medicac/o, Tn folium, Onobrychis, etc., and Boisduval asserts that they 

 will not touch arborescent leguminous plants. The naming of many 

 species by the early entomologists, after plants belonging to other 

 natural orders, owing to a supposed connection between the insect 

 and the plant, is frequently based on error, e.g., such names as ftlipen- 

 dulae, cynarae, achilleae, lavandidae, peucedani, brizae, etc. Yet the 

 larvae of some species are not altogether confined to a leguminous 

 diet, that of A. erythrus is stated by Milliere to feed on Thymus, 

 Nicholson says that A. sarpedon feeds on Eryngium, whilst A. pui-pu- 

 ralis (minos) and A. exulans have the reputation of feeding on quite a 

 number of plants other than those belonging to the Leyuminosae. We 

 are inclined to think that the more polyphagous species of this genus 

 are, as a rule, the more ancestral ones. 



The full-grown larva usually forms a spindle-shaped, white or yel- 

 low, silken cocoon, which is fixed either to the stem of a plant or to the 

 ground. (The cocoon of A. nicaeae, however, is quite oval in shape, 

 differing very much from a typical Anthrocerid cocoon.) The pupa is 

 remarkable as being of a very generalised type, with the appendages 

 long, and free from the abdominal segments ; of the latter 3-7 are 

 free in the male, 3-6 in the female ; the abdominal segments 1, 2 are 

 also more or less free in both sexes. The pupal state usually lasts 

 but a short time, and, just before the emergence of the imago, the 

 pupa pushes itself partly out from the upper end of the cocoon, 

 the imago liberating itself from the protruding chrysalis. We are 

 not aware that any really double -brooded species of this genus 

 exists in a state of nature. Milliere certainly gives A. faiista, 

 and doubtfully A. achilleae, as being so in southern France, and 

 Boisduval also suggests the double-broodedness of the latter species, 

 but our observations on this species there are contrary to this view, and 

 Boisduval's own reason, founded upon a comparison of the dates of emer- 

 gence of the species in the neighbourhood of Paris with those in the^ 

 higher mountains of Dauphine, is not at all convincing. Ochsenheimer 

 met with two newly-emerged specimens of A. trifolii in late autumn, and 

 Zeller found a late autumnal freshly-emerged specimen of A. Jilipen- 

 dnlae, the latter suggesting that these were second-brood specimens 

 from larvae that had not become torpid. The probability is, however, 

 all the other way, as we have found belated specimens of A. jilipemhdae 



M 



