CHALCIDID^E. 



207 



Fig. 130. 



campce Harris infests Clisiocampa. " Pteromalus apum is 

 parasitic in the nests of the Mason-bee." (Westwood.) A spe- 

 cies of this or an allied genus (Fig. 139) 

 infests the eggs of the Clisiocampa Ameri- 

 cana. Its eggs are probably laid within 

 those of the Tent-caterpillar moth early 

 in the summer, hatching out in the autumn, 

 and late in the spring or early in June. 



An allied genus, Siphonura, is a para- 

 site on galls. It resembles a beetle, Mor- 

 della, from its very peculiar scutum. 



The antennae of Semiotellus are twelve-jointed. S. (Ceraph- 

 ron) destructor Say (Fig. 140), according to that author, 



destroys the Hessian-fly, while lying 

 in the "flax-seed" state. Fitch de- 

 scribes it as being a tenth of an 

 inch long, black, with a brassy 

 green reflection on the head and 

 thorax, while the legs and base of 

 the abdomen are yellowish. 



In Encyrtus , which comprises 

 over a hundred species already 

 known, usually rather small in 

 size, the body is short and rounded. 

 The eleven-jointed antennae are inserted near the mouth. The 

 thorax is square behind, and the sessile abdomen is short and 

 broad at the base. Encyrtus Bolus 

 and E. Reate are described from 

 North America by Mr. F. Walker. 

 Encyrtus varicornis is in Europe 

 found as a parasite in the cells of 

 Eumenes coarctata. 



The antennas of Eulophus are nine- 

 jointed, with a long branch attached to the third, fourth, and 

 fifth joints. The abdomen is flattened, sessile. E. basalis 

 Say was described from Indiana. We figure a Chalcid (Fig. 

 141, <?), allied to Eulopus, which preys upon the American 

 Tent Caterpillar. 



A species of Blastophaga (B. grossorum Grav.) is interest- 

 ing as it is the means of assisting in the fertilization of the Fig 



Fig. 140. 



