300 



THE CANADIAN ENTOMOLOGIST. 



LiFK-HISTORY. 



The development of the last and overwintering brood was studied. 

 Females were observed ovipositing on September 13th. The time oc- 

 cupied in the process varied. A single female, which was isolated for 

 observation, remained in the same position for 1^2 hours (see Fig. 20) 

 with her ovipositor inserted in the cocoon. She then removed her ovi- 



jiositor and walked away, moving about for twenty 

 minutes, after which she returned and inserted her 

 ovipositor in almost the same spot as before and 

 remained in this position ovipositing for fifty-five 

 minutes. 



In several instances two females were seen ovi- 

 positing in the same cocoon. The numerical 

 abundance of the eggs that may be deposited in 

 a single cocoon may be judged from the fact that in one case eighty-one 

 eggs were counted on a single larva ; in another case forty-seven pupae 

 and adults were contained in a single cocoon. The sawfly larvae in 

 cocoons in which the chalcids had deposited eggs appeared less active 

 than those in uninfected cocoons ; this may be due possibly to some 

 paralysing action on the part of the female when ovipositing. 



The eggs are .3 mm. in length and transparently white. In shape 

 they are ovally elongate, having one end broader than the other, and are 

 slightly curved (Fig. 21). They are deposited externally upon the larva, 



Fig. 20. — Female C. nematici- 

 da ovipositing" on cocoon of 

 Lygicon p mat lis erichson it 

 Harlig-, X 2^2- 



X 15 



X 3o. 



Fig. 21. — Interior oi anterior end of cocoon of L. erichsonii, showing^ eg-^s of C. nematicida 

 deposited on the sawHy larva, x 15. Also single egg of C. iicmaticidn, x 30. 



chiefly in the anterior and thoracic region and appear to be laid in masses 



