162 HICKORY. LEAVES HICKORY TUSSOCK-MOTH 



solitary. The state of the atmosphere influences them somewhat 

 as to the time of spinning their cocoons. Ten worms which I 

 reared in a cage together from their infancy, after a period of 

 severe drouth, on the occurrence of a rainy day the second of 

 September, spun their cocoons simultaneously, all save one which 

 performed this labor ten days earlier. When ready to form its 

 cocoon the caterpillar crawls into some secure cavity, in the 

 crevices of a wall or beneath a stone, to which the cocoon is very 

 slightly attached. From this the winged moth is given out the 

 following spring, though when reared in a dry room I have known 

 individuals to come forth in their winged state the latter part of 

 October and in November. These moths pertain to the family 

 Arctiid^ or the Tiger-moths. They cannot be referred to any 

 of the genera denned by the European naturalists, and Dr. Harris 

 (New England Insects, p. 279) has therefore constructed for them 

 a genus which he names Lophocampa, a word meaning crested 

 caterpillar. He indicates lour species pertaining to this genus, 

 and the caterpillars oi two additional species are known to me. 



The Cocoons of the hickory tussock-moth are of a regular oval form, nearly 

 an inch long and over a half inch broad, of an ash gray color, composed exte- 

 riorly of the short stiff hairs of the caterpillars, woven loosely together and 

 with their points standing in all directions, so that it is impossible to touch one 

 of these cocoons without having the skin filled with these hairs, resembling 

 cowhage and producing the same irritation of the skin which that substance 

 causes. The pencils of long black hairs of the caterpillar are separated and 

 drawn in among the others so skilfully that the eye is seldom able to discern 

 their color. The whole are held together by a thin clothlike fabric formed of 

 white silken threads matted closely together which lines the cocoon upon its 

 inner side. Its texture is so slight that when the moth is 

 ready to leave the cocoon, by merely crowding its head for- 

 m ward it ruptures it at one end, and forms a round orifice 

 Bw through which it makes its exit, elongating the cocoon slight- 

 ly hereby, at this end, as represented in the accompanying 

 figure. 



The Chrysalis or pupa lies in the cocoon with the black head and other 

 relics of the larva at its pointed end. It is 0.70 long by 30 in diameter, of a 

 pale chestnut color, its sutures marked by slender black impressed lines, and 

 the breathing pores forming a row of seven oval black dots along each side. Its 

 surface is smooth, without those rows of little spines which we see in the pupa 

 of the peach borer and several other moths, and the empty shell remains with- 

 in the cocoon after the moth is disclosed. The figure presents a 

 dorsal view of the sutures, breathing pores, &c, but is unduly 

 contracted on the anterior half, the width here being the same 

 as across the middle. 



