NATURAL ENEMIES. 



35 



Egg Parasites. 



There were two egg parasites, one, a true egg parasite developing 

 within the egg, and the second, a parasite the eggs of which are prob- 

 ably deposited in the alfalfa stems among, but not in, the eggs. The 

 larva of the latter is predaceous on the masses of weevil eggs as placed 

 by the female weevil, and among them it develops to the adult. 



MYMARID EGG PARASITE. 



A mymarid egg parasite, AnapJies sp. (fig. 15), was found in all 

 of the seven shipments received from Italy. It was received in all 

 stages of development, except perhaps the egg and adult, and was 

 either left in the same boxes, these being perforated with holes and 



Fig. 16. — Imported pteromalid egg parasite of the alfalfa weevil: Adult. Greatly enlarged. (Original.) 



glass tubes inserted (PL XI, fig. 2), or placed in specially prepared 

 boxes (PL XI, fig. 3) which were also perforated and had glass tubes 

 inserted. The parasites were reared from this imported material, 

 and from the parent stock two generations were reared on American 

 egg masses of the alfalfa weevil. The third generation, together with 

 others of the first and second generations and natives from later ship- 

 ments, was placed in field reproduction cages (PL XII, fig. 3) to 

 the number of about 300. These cages were overstocked with eggs 

 by confining numbers of weevils in them. After about 10 days the 

 covers to these cages were removed, thus allowing the generation of 

 parasites that developed within them to escape and scatter freely 

 over the fields. 



PTEROMALID EGG PARASITE. 



A pteromalid egg parasite (fig. 16) was likewise found in all of the 

 seven importations. The larva (fig. 17) feeds externally on the egg 

 masses in the alfalfa stems, later transforming to the pupa (fig. 18); 



