THe HyMenortera or MINNESOTA 187 
pine weevils and various other insects. They also breed in Pimpla and 
many other primary parasites. 
S. Marcovitch has bred Habrocytus obscuripes Ashm., and Cato- 
laccus perdubius Gir. in the Minnesota insectary, from the strawberry 
weevil. (16th Rep. State Ent. Minn. 1916). 
§ 
4 
4 
L Fig. 70. Collopisthia nematicida Pack, parasite of larch 
Fig. 69. Pteromalus puparum. sawfly.—F'rom a colored drawing. 
SPALANGIIDAE 
Antennae 12-jointed. Abdomen distinctly petiolate. First tarsal joint not swol- 
len. 
The minute Spalangia muscae has been bred from Stomoxrys pupae. 
The same species is known to attack the pupae of both the horn fly 
and the house fly. Parasitism by this species always takes place in the 
pupal stage of the host. In a collection of Stomoxys pupae made in 
Texas, it was found that 40 per cent were parasitized by this insect. S. 
hirta Haliday, confined with horn fly pupae promptly attacked the latter. 
S. lanaiensis Ashm. has been reared from dipterous pupae. The 
latter two species are evidently important enemies of the horn fly. 
TRIDYMIDAE 
Abdomen almost sessile. Antennae 12-jointed; pronotum scarcely visible in the 
middle; funicle of antennae 5-jointed. 
Hemadas nubilipennis Ashm. has been reared from galls on 
huckleberry made by Solenozopheria vaccini Ashm. 
