482 THE BUTTERFLIES OF NEW ENGLAND. 



Borrago officinalis, — both again introduced plants ; and it is reported 

 (perhaps by mistake for its congener, V. atalanta) to have been found on 

 the nettle. Moschler remarks that he has received neither thistles nor 

 nettles from Labrador, and wonders upon what the caterpillar may feed 

 in that inhospitable region ; we would suggest that Artemisia or Ana- 

 phalis may serve it. In Europe it has been taken upon various species of 

 Carduus, Cnicus,* Onopordon and other Cynaroideae, such as Centaurea 

 benedicta and Cynara scolymas ; one of the Anthemideae, Achillea mille- 

 folium, and some Inuloideae, such as Gnaphalium arvense, and Filago 

 arvensis : on Echium, one of the Borraginaceae, and on Malva rotundifolia. 

 It is also reported now and then on nettle, but perhaps erroneously, 

 its resemblance to V. atalanta being deceptive. It should, however, be 

 added that its occurrence on nettle has been especially noted in remarkable 

 cardui years. Rambur says that after having devoured Carduus, Cnicus 

 and Centaurea, it attacks Echium, Ulmus, etc. It seems to prefer the 

 Malva in Egypt, being found abundantly on the species cultivated by the 

 Arabs for medicinal purposes and called by them Mlukheh (pronounced 

 Molochia) , while the thistles growing abundantly by the railways are un- 

 touched ; since this mallow is cut at various times during the winter, 

 myriads of the caterpillars are doubtless annually exterminated. Examin- 

 ing one September in the Botanic Garden in Cambridge a whole series of 

 thistles growing side by side, I found that the butterfly had chosen almost 

 exclusively a plant of Onopordum, a few larvae being found also on a 

 couple of European species of Cnicus. In Java, according to Horsfield, 

 it feeds on an Artemisia, called Godomollo by the natives ; in Ceylon 

 also on Artemisia, according to Moore, and in Bombay "on different 

 species of Blumea" according to Aitken, quoted by de Niceville. 



Habits of the caterpillar. The young caterpillar makes its escape 

 from the e^g^, as usual among lepidopterous larvae, by biting a slit almost 

 around the crown of the Qgg, and pushing up this improvised lid ; it does 

 not appear to devour the egg-shell, as caterpillars usually do, but, after 

 biting a few little holes partly through the upper surface of the leaf, makes 

 its way to the opposite side and takes up a position, each one apart from 

 its fellow, either between the midrib and curled-up rim, if near the tip of 

 the thistle leaf, or next the midrib or a lateral rib, if farther back, or be- 

 tween the tips of the crenulations ; here it bites away the silken film of the 

 leaf and makes a nest, covering itself with a slight open web, into which it 

 weaves the bitten particles of the film. From this retreat it sallies forth to 

 eat irregular patches in the parenchyma, which it often partially covers 

 with an extension of the web. 



Each caterpillar, when it has outgrown this confined abode, builds for 



* Speyer says that in a period of great abun- and palustris, the first two of which are found 

 dance cardui feeds on Cnicus arvensis and in America, the last two not. 

 lanceolatus, but leaves untouched C. oleraceus 



