BULLETIN 1182, U. S. DEPARTMENT OF AGRICULTURE. 
ADULT. 
This species is the only North American representative of the genus 
Diprion and may be readily distinguished from the other Nearctic 
species belonging to the subfamily Diprioninae by the large and 
densely punctured metascutellum. The- specimens which have been 
examined show very little variation, and all seem to represent the 
typical form of the species. 
Female (Fig. 1, a).— Length 7 to 9 millimeters. Clypeus truncate; head with large, 
rather close punctures; postocellar area convex and more than twice as wide as long; 
postocellar furrow well defined; antenna distinctly tapering, the joints much broader 
than long and with very short rami (apical joints practically without rami), third joint 
distinctly longer than the 
fourth; 'scutum shining, 
with large, distinct punc- 
tures; scutellum and met- 
ascutellum opaque and 
with the punctures closer; 
tibial spurs simple; pad- 
like part of sheath ellip- 
tical in outline and close 
to the median line; apical 
sternite deeply angulately 
emarginate medially, 
lancet with nine rows of 
regular teeth . Black with 
yellow markings; head 
black except yellow clyp- 
eus, supraclypeal area, 
and scape; thorax yellow 
with the following parts 
black: Sternum, mesepi- 
meron, large spots on pre- 
scutum and scutum, lat- 
eral part of scutellar area, 
and metascutellum; ab- 
domen yellow with ter- 
gites 3 to 6 inclusive and 
median spots on following 
two black; legs, except 
the somewhat dusky fem- 
ora, yellow; wings hya- 
line, venation pale brown 
with stigma somewhat 
darker and the cost a 
somewhat paler. 
Male(Fig.l, 6).— Length 
5 to 7 millimeters. Agree- 
ing with female in general 
structure; antenna long, 
Fig. l 
Female; b, male. 
the basal rami slightly less than half as long as half the flagellum; hypandrium dis- 
tinctly punctured, broadly rounded posteriorly; head and thorax more coarsely 
punctured than in the female; valves of penis, when seen from the side, broad and 
the ventral margin armed with small, widely separated teeth. Black; venter of ab- 
domen and legs beyond trochanters dark rufous; wings hyaline, venation pale brown, 
costa paler. 
EGG AND EGG SLIT. 
^ The eergs of the imported pine sawfly are about 1.5 millimeters long, with straight 
sides and bluntly rounded ends. They are oval in cross section, being 0.5 millimeter on 
the greater transverse diameter and 0.25 millimeter on the lesser transverse diameter. 
When first laid the eggs are pale whitish blue, translucent, shining, much like gelatin, 
and somewhat smaller than the above dimensions. After several days, development 
becomes marked by swelling and the color appears bluish green. When about to 
hatch they are quite swollen, sometimes as long as 1.75 millimeters, and are dark 
green. (Fig. 2, b.) 
