176 Annals Entomological Society of America [Vol. XI, 



body is drawn forward until the abdomen is in a vertical position. 

 The ovipositor is then inserted into the cocoon after which the 

 abdomen again assumes its normal position and the ovipositor 

 sheath slips into its place in the groove on the ventral side 

 leaving only the ovipositor proper in a vertical position. At 

 the same time the ventral segments are extended downward 

 and forward, forming a triangular piece below the abdomen 

 from the vertex of which the ovipositor extends. In removing 

 the ovipositor this operation is reversed. 



Fig. 1. Female Dibrachys clisiocampcE Fitch in position of oviposition. 



As soon as the ovipositor is thrust into the cocoon the larva 

 within becomes excited and moves about in an effort to get out 

 of the way. The parasite thrusts its ovipositor into, the larva, 

 but does not deposit any eggs. It may stab it several times in 

 different places before removing the ovipositor from the cocoon 

 but no eggs are deposited until the larva within the cocoon is 

 quiescent. This operation is repeated over and over again by 

 the parasite as she walks from cocoon to cocoon, always 

 stabbing the active larva with her ovipositor but never ovi- 

 positing in it. In from 6 to 24 hours the larvae thus stabbed 

 become sluggish and finally die. 



When the parasite inserts her ovipositor and the larva 

 remains quiet, she deposits her eggs on the surface of the body, 

 usually in wrinkles in the skin. Usually two or three eggs are 

 deposited in a place but often they are placed singly. The 

 ovipositor can be bent in any direction and the egg after being 

 forced almost entirely out, can be held by the tip and placed in 



