FAMILY GOSSAMER-WINGED BUTTERFLIES. 131 



the West has not been found nearly so far north. It 

 occurs only in the vicinity of water where alders flourish 

 and is consequently a local insect and flies but short dis- 

 tances. The most remarkable feature in its life-history is 

 the food of the caterpillar, it being the first and almost the 

 only case known among butterflies in any part of the world 

 of a strictly carnivorous habit; its food is confined to plant- 

 lice (aphides) and especially those kinds which exude a 

 fluffy secretion and live in close colonies; into these 

 colonies the caterpillar intrudes, ploughing its way into 

 the mass, and as one after another of the bodies of its vic- 

 tims are sucked dry, their skins are utilized by being 

 involved in the thin loose lining of silken tissue which the 

 caterpillar weaves as it works its way. With a view to this 

 life the butterfly lays its eggs singly upon the twigs of the 

 plant infested by the colonies of plant-lice and in their im- 

 mediate vicinity or even directly among them. These eggs 

 are of a flattened spheroidal shape with exceedingly delicate 

 reticulation and of a faint green color, nearly pellucid, and 

 hatch in three or four days. The caterpillars attain their 

 growth with unusual rapidity and moult but three times, 

 so that sometimes the chrysalis state is assumed within a 

 fortnight of the laying of the eggs from which the cater- 

 pillars are born ; the chrysalis, however, hangs an ordinary 

 length of time, from eight to eleven days. In our district 

 there seem to be three broods of this butterfly, which 

 hibernates as a chrysalis, though possibly also as a butter- 

 fly; farther south the number of broods is probably greater. 

 With us the first brood flies from the latter part of May to 

 the middle of June; the second brood appears early in 

 July and flies into August; the third from the middle of 

 August until near the end of September. 



Another and western genus of Coppers, Gaeides, is represented in 

 our district by O, diojie, which occurs from Missouri to Iowa. 



