300 



BEES AND WASPS 



able to maintain itself even in the absence of any one species 

 of plant lonse. 



Fig. 242. — Pteromalus puparum: female at left; male at right — highly 

 magnified. (Chittenden, Div. Ent., U. S. Dept. Ag.) 



Fig. 243. — Chalcis ovata, a parasite of the alfalfa caterpillar: a, pupa; 

 b, parasitized pupa of tussock moth (Hemerocampa leucostigma) : c, adult; 

 d, same in profile; e, pupal exuvium. Enlarged. (From Howard.) 



Family Chalcididae. — The family Chalcididop, one of the 

 groups which includes extremely minute insect forms which 

 parasitize insects, such as the plant lice, scale insects, and 



