244 



A A' ECONOMIC EXTOMOLOGY. 



We have many species of considerable size belonging to the 

 genus Argynnis^ which resemble each other more or less by 



in color, with irregular black or blackish blotches, spots, and 

 lines, and a little silvery mark resembling a comma or semicolon 

 on the hind wings beneath. Of these the caterpillar of G. comma 

 feeds upon the hop-vine, although it rarely does any serious 

 injury. It is reddish or yellowish in color, with a black head 

 and black branched spines, and forms an angular chrj^salis which 

 is suspended by the tail. The chrysalis is yellowdsh green in 

 color, with prominently marked segments, and has the thorax 

 produced into a somewhat acute process. 



Another very common, almost cosmopolitan butterfly, is the 

 Vanessa ayitiopa^ popularly known as the "mourning-cloak." 

 It is of a very dark, rich-brown color, with a broad yellowish 

 border on both wings. It winters in the butterfly stage, and 

 may often be seen on w^arm days in midwinter, fluttering about in 

 the woods, w^hile it is the earliest of the butterflies to make its 

 appearance in spring. The caterpillars feed upon quite a variety 

 of plants, notably willow^ and poplar, and often in great colonies. 

 When full grown they are two inches or more in length and black, 

 with red-marked, branched spines. The chrysalis is suspended 

 by the tail, and of a somewhat mouse-gray color, the segments 

 marked with acute spines. This may under circumstances be- 

 come a troublesome insect, but it is easily controlled, either by 

 arsenical poisons, as the caterpillar feeds exposed, or by hand- 

 picking, which is easy because of the gregarious habit when 



Grapta progne .—'Xs 'Wig's, of right side detached 

 to show under side ; this is almost like G. 



comma. 



Fig. 254. 



their tawny upper sides 

 marked with black spots, 

 and by having the under 

 sides more or less marked 

 wdth silvery blotches, es- 

 pecially on the hind wings. 

 None of them are injurious, 

 the lar\-ae feeding upon vio- 

 lets. In the genus Grapta 

 there are species with 

 strongly and irregularly 

 angulated and toothed 

 wings, quite dark brown 



