HISTORY OF INSECTS. 71 



found more than a single grub in each individual : 

 when all the interior of the hop-fly is consumed 

 by the grub of the ichneumon, it will be found 

 separate from its fellows, and motionless, usually 

 on the upper side of the leaf, to which it is glued 

 by some viscid exudation. 



225. The hop- fly now appears distended, and 

 of an opaque hazel or lighter tint ; if opened, 

 the full fed grub of the ichneumon will be dis- 

 covered doubled up and filling the cavity, its 

 head being next the tail of the hop-fly : in a 

 short time the parts of the perfect insect are 

 developed in a quiescent state, and in the same 

 position, the integuments of the grub being 

 doubled up below it in black grains : it spins no 

 cocoon, being adequately protected by the indu- 

 rated skin of its victim. 



226. A few days are sufficient to give con- 

 sistence to its parts ; and while the new-risen sun 

 is yet glistening in the early dews, the winged 

 insect, by a push of its head, detaches the latter 

 rings of its case, which separate in the form of a 

 circular lid, often springing back to close the 

 orifice after the inhabitant has gone forth, born in 

 the maturity of her energies and instincts to 

 renew the circle of existence.* 



The account of this parasite is copied from Mr. Haliday's Essay 

 on Parasitic Hymenoptera, in the Entomological Magazine: the 

 author has witnessed precisely the same facts, in regard to the hop- 

 fly, which Mr. Haliday relates of the aphis of the rose. 



