FAMILY HABITS IN BUTTERFLY LARV^ THE VANESSIDS. 25 



that the Satyrids have long-lived, solitary, grass-feeding, winter larvae, 

 that the Pierids have short-lived, summer-feeding larvae, inclined to 

 develop, in most broods, some rapidly-feeding larvae, or " forwards," 

 thus tending to the production of more than one brood in a year, 

 and the Ruralids short-lived, solitary, tree-feeding, summer larvae, 

 and so on. 



These are, as we have hinted, general impressions, quite true in 

 the main, and yet not at all so in detail, for we have to admit, so soon 

 as we give careful consideration to the question, that the general 

 impression bristles with exceptions, and the fact that these similarities 

 and dissimilarities in the habits of the larvae of allied species have 

 never been properly reviewed, even so far as relates to our British 

 species, is our only excuse for writing this and the following chapters. 



If we consider the larval habits of the Vanessids first, as being 

 among the best known of all butterfly larvae, we shall at once be 

 struck with the fact that the genera Araschnia (levana), Aglais [urticae), 

 Eugonia (polychloros), Vanessa (io), and Euvanessa (antiopa), all have 

 summer-feeding gregarious larvae, whilst Pyrameis {atalanta, cardui) 

 and Polygonia (c-album) have summer-feeding solitary larvae. It may 

 be at once urged that these are, of necessity, summer-feeding larvae, 

 because the species hybernate in the imaginal stage, but here one is 

 met with the fact that Araschnia levana, with larval habits closely akin 

 to those of Aglais urticae, hybernates as a pupa, and not as an imago, 

 and yet has two broods per year, coinciding almost exactly with those 

 of A. urticae and Polygonia c-album. It is also clear that a purely 

 summer-feeding habit of the larvae involves the recognition that the 

 species of butterflies that have this habit must live through the winter 

 as eggs, pupae, or imagines, i.e., that species that pass the winter as 

 eggs, pupae, or imagines, must have a summer-feeding, and cannot 

 possibly have a winter-feeding, habit. Here, then, the comparative 

 uniformity of the imaginal habit of wintering as such, is largely 

 responsible for the summer-feeding habit of Vanessid larvae. Similarly, 

 too, the fact that most of the Vanessid imagines lay their eggs in 

 comparatively large heaps, may be looked upon as the basis of the 

 gregarious habit in so many Vanessid larvae, yet it cannot be over- 

 looked that hundreds of species of lepidoptera, in other superfamilies, 

 lay their eggs in large batches, imbricated, overlapping, etc., and yet 

 have larvae of most marked solitary habits. Still, unconnected 

 as the two things are in other superfamilies, yet, in butterflies, it is 

 quite clear that it is an important factor, and, even in the Vanessids 

 with solitary larvae, the solitariness is often very partial, the £ butter- 

 flies rarely laying only one egg on a plant, although laying them 

 singly, but usually several pretty close together, and hence we usually 

 find many larvae at no great distance from each other in the solitary 

 species. Thus we often find several larvae of Pyrameis cardui, each in 

 a separate leaf, or bunch of leaves, on one thistle plant, several dozen 

 larvae, maybe of P. atalanta, on a large bed of nettles. We frequently 

 find, also, many larvae of Polygonia c-album on a currant bush, but 

 this species is reputed to often lay five to seven of its eggs in close 

 proximity, and so on. It is, however, very surprising to find that, where 

 the species are distributed over the whole of the Palaearctic and 

 Nearctic areas, as is the case with Pyrameis atalanta, P. cardui, 

 Euvanessa antioya, etc., the habits of the larvae are identical, although 



