70 Journal of A gricultural Research vot. xiii, no. i 



HIBERNATION 



The insect hibernates in the larva stage in cocoons spun in the autumn 

 after the larvae have fully developed. In the peach orchard a large per- 

 centage of the overwintering insects spin their cocoons in small cracks 

 in the bark, under bark flakes, and in curled ends of bark strips on the 

 trunk and large branches of the trees. The range of places for spinning 

 is shown in the following list of locations in which cocoons were observed 

 in April, 191 7, at the United States Department of Agriculture experi- 

 mental farm near Rosslyn, Va. : (i) Under edges of bark scales; (2) in 

 axils of fruit spurs; (3) in the curled ends of scales of bark; (4) beneath 

 scales at axils of secondary branches; (5) between mummied peaches on 

 the trees and on the ground; (6) between peaches and the spur bearing 

 them; (7) in old bark wounds; (8) in the frass at enlarged ends of twigs 

 fed upon last season by the larvae; (9) in the wrinkles of mummied peaches 

 on the ground; (10) on the smooth bark of the twigs; (11) in burrows 

 made by barkbeetles; (12) in holes formerly filled with pith at end of 

 stub made by pruning; (13) in the hollows of stubble. 



PARASITES' 



Eight species of hymenopterous parasites have been reared. Six of 

 them are primary and two are secondary parasites. One dipterous para- 

 site, Hypostena variabilis Coquillett, was reared from larvae collected in 

 the orchard. It pupated within the partially constructed cocoon of the 

 host. The host was probably attacked while the larva was seeking a 

 cocooning place. 



Of the six primary hymenopterous parasites, Macrocentrus sp. was 

 most abundant. Macrocentrus sp. (Q. 7897) attacks and develops 

 within feeding larvae of Laspeyresia molesta, spinning its cocoon within 

 the cocoon of the host. The latter may be thin and unfinished, due to 

 the weakened condition of the larva. This species is also a parasite 

 of the codling moth, L. pomonella. Phaeogenes sp. (Q. 7204) was 

 second in abundance. Phaeogenes emerges from the pupa of the host 

 and probably attacks the insects in the prepupa or pupa stage. Sev- 

 eral specimens of Ascogaster carpocapsae Viereck were reared. Accord- 

 ing to Mr. Cushman, A. carpocapsae oviposits in the egg of the host, 

 kills the insect as a larva after it has spun its cocoon, and spins its own 

 cocoon within that of the host. One specimen each of Spilocryptus sp. 

 (Q. 6833) , Mesostenus sp. (Q. 1 345) , and Glypta vulgaris Cresson were 

 reared. Spilocryptus attacks the host after the larva has spun its 

 cocoon, and the adult parasite emerges from the pupa of the host. 

 Glypta and Mesostenus attack the feeding larva and kill the host in 

 the prepupa stage. Each one spins its cocoon within the cocoon of the 

 host. 



> Through the assistance of Mr. R. A. Cushman, of the Bureau of Entomology, United States Depart, 

 ment of Agriculture, the writers are enabled to give the breeding habits of the parasites and the relation 

 of the parasites to the host. 



