THE IMPORTED PINE SAWFLY. 
Fig. 2—Diprion simile: a, Eggs in position in needle; b, egg, show- 
ing embryo; c, needle, showing eggs in pockets. 
The eggs are laid in slits in the needles (Fig. 2, a). Adults emerg- 
ing early lay in last year's needles, but those emerging when the 
present year's needles are of sufficient size appear to prefer these. 
The number of eggs deposited in a single needle varies. In the 
needles observed, from 2 to 16 eggs were laid, with an average of 8. 
Where more than one egg is laid the egg pockets adjoin one another, 
with merely a wall be- 
tween. The pocket or 
slit is cut into the 
convex portion of the 
needle from an edge 
at an angle and the 
tissue composing the 
walls of the slit is of 
two textures (Fig. 2, 
c) . The basal portions 
of these walls are the 
rather tough outer 
coating of the needle 
and the apical por- 
tions are delicate 
membranes, a p p a r - 
ently made of torn 
needle pulp, which are 
pressed together fol- 
lowing the laying of 
the egg, seal it in place, and somewhat conceal it. As the egg 
increases in size, it parts these lips and becomes exposed. When 
freshly made the cuts are yellowish green and the needle dark green, 
but as the eggs mature the cuts become somewhat brownish and 
the needles yellowish. 
LARVA. 
The following description 3 was made from a full-grown, sixth-instar larva of Diprion 
simile which had been preserved in alcohol. (Fig. 3.) 
Length 20 millimeters; maximum breadth, across the metathorax, 4.5 millimeters. 
The head is circular in outline viewed from in front and the front plane slightly convex 
viewed from the side ; frons 
and epicranium with a few 
fine hairs; epistoma with 4 
hairs; labrum with 4 hairs; 
eye disks not elevated, 
eyes large, lenses convex; 
antennae between and 
slightly closer to pleurosto- 
mata than eyes, composed 
of cone and two disks or 
partial ring joints ; maxillae 
with cardo, stipes, palpifer 
and 4-jointed palpi, galea, 
and lacinia; lacinia not flattened, rather triangular in outline viewed from apex, 
armed with large hornlike process or seta on the side toward labium and with rather 
large setae forming an apical transverse row on the side of the_ lacinia parallel with 
the Interior surface of the trophi; labium with palpiger and 2-jointed palpi. Thorax 
with the tergum composed of areas A, B, C, and D; A excepting in the prothorax, B, 
3 The terminology used in describing the larva is that used by the writer in the descriptions of Keodi- 
prion lecontei (Fitcn) (Jour. Agr. Research, v. 20, no. 10, p. 741-760. 1921), with the changes adopted in 
u Some suggested homologies between larvag and adults in sawflies'' (Proc. Ent. Soc. Wash., v. 28, no. 
8, p. 173-192, 1921 j. 
Fig. 3.— Diprion simile: Full-grown larva. 
