160 SEVENTEENTH Report STATE ENTOMOLOGIST OF MINNESOTA—1918 
TENTHREDINIDAE 
Agrees with the preceding description of Diprionidae except as follows: Meso- 
episternum not divided into plates; proepisternum divided into two plates; antennae 
seven to twelve-jointed, never serrate or pectinate. 
Characterized by a large number of species, at least 2,000 being 
known, amongst them some of our most common pests, for example, 
the pear and cher- 
ry slug, larch saw- 
fly, currant worm, 
the imported and 
native, the former 
being green and 
black, spotted in the 
adult larval stage, 
Fig. 36. Lygaeonematus erichsoni Hartig. The Larch while the latter, 
SENN with the excep- 
tions of its black 
head, is all green. In this family occur the rose slugs, raspberry slug, 
pine sawfly and other pests. 
Eggs are laid in slits cut by females in the leaf of host plant; in 
currants, gooseberries and some other plants the eggs are laid on the 
under side of the leaf. The larvae of some of the species “skeletonize” 
the leaf, eating only the softer tissues, while others, like the currant 
Fig. 37. Lygaeonematus erichsoni Hartig. The Larch Sawfly, male and female 
and tips of abdomens. 
