THE HyMENOPTERA OF MINNESOTA 155 
MEGALODONTIDAE 
Hind margin of the pronotum, or collar, straight or nearly so, being nearly the 
shortest distance between the fore margins of the tegulae; dorsulum never extending 
much beyond the fore margins of the tegulae; proepimeron wanting; first perapterum 
wanting; fore tibiae with two spurs. 
Inhabit woods, flying in 
the sun, settling on leaves 
and occasionally, but rare- 
ly on flowers. Larvae 
smooth, cylindrical, with 
six short articulate and no 
prehensile legs. Feed on 
leaves of trees and inhabit 
webs of their own making. 
Pupa changes in a silken 
cocoon on the stem of the 
tree it inhabits, or on the 
ground. IJtycorsia discolor 
Cress, and Pamphilus per- 
Fig. 30. Sterictiphora johnsoni MacGill; male. sicus MacG. occur in 
a “sy 
Minnesota. 
CEPEEDAE 
Hind margin of the pronotum, dorsulum and proepimeron as in Megalodontidae; 
first perapterum present and seen a short distance below the tegulae as a small free 
plate; fore tibiae with one spur; basal joints of the flagel separate; intercostal vein 
wanting, radial cell with one cross vein; species slender and elongate. 
Cephus pygameus Linn., is known as a wheat-stem borer, an in- 
troduced insect; in Europe it attacks corn. Another form, Janus 
integer Nort., bores in pith of currant. Another works in blackber- 
ries, entering at the bottom and boring upward. 
Janus abbreviatus Say, 1s a Minnesota species. 
XYELIDAE 
Hind margin of pronotum, dorsulum, proepimeron and first perapterum as in 
Cephidae; fore tibiae with two spurs; basal joints of the flagel consolidated into a 
long basal joint; intercostal vein present, radial cell with two cross veins; species 
robust. Larva footless. 
Imagoes appear early in the year, February, March and April, 
deposit their eggs and disappear, so that few specimens are taken 
and only the common forms known. Newman says of the group: 
“Inhabits fir trees, occasionally settling on umbelliferous plants.” 
Ent. Mag. II, p. 408, 1834. Dyar, however, is reported as finding 
