INSECT ENEMIES OF EASTERN FORESTS 553 
or third week in July may transform to adults in August or September, 
or some may remain dormant in the prepupal stage in the cocoons and 
not develop to adults until late in April to July of the next year. 
Larvae maturing from late in July to October do not transform to 
adults until the following spring or early part of the summer, and 
sometimes a few prepupa! larvae may remain dormant and not trans- 
form to adults until the second year. Broods of larvae may therefore 
be found feeding from May until late in the fall, the exact periods 
depending somewhat on the climatic range. The eggs are deposited 
singly in slits cut in the needles, but usually several eggs are laid in 
each needle. The larvae become full grown in from 25 to 31 days, 
and the winter is passed as prepupal larvae in capsule-shaped cocoons 
in the duff or topsoil beneath trees. 
The larva of the white pine sawfly (Neodiprion pinetum (Nort.)), 
also called Abbott’s pine sawfly by some authors, is yellowish white 
with four longitudinal rows of black spots on the body. The head is 
black. The larva is nearly 1 inch long when full grown. White 
pine is the preferred food plant, but published records show that this 
sawfly is occasionally found on pitch, short-leaf, red, and mugho pines. 
This species is distributed throughout the eastern part of the United 
States, westward into Minnesota and Jowa, and northward into the 
Provinces of Ontario, New Brunswick, and Quebec, Canada. The life 
cycle and habits are very similar to those of the red-headed pine sawfly. 
Neodiprion nanulus Schedl is known locally as the red pine sawfly. 
The larva, when nearly full grown, is about 34 inch in length and 
ranges in color from dull grayish green to blackish on top and green- 
ish white beneath. It has a middorsal stripe of hght green and a 
fainter one on each side, also a dull blackish stripe at the bases of the 
legs. The head is black, and the thoracic legs are black with whitish 
annulations (fig. 146,C). After the full-grown larva has ceased feed- 
ing, and before it spins the cocoon, it becomes dull green with four 
more or less distinct longitudinal blackish stripes on the body, and 
the head is yellowish brown. This species, unknown prior to 1932, 
has now been reported from New Jersey and New York, north into 
Quebec and west into southeastern Manitoba. Its favored food plant 
is red pine, although it has been found feeding on jack, Japanese red. 
and mugho pines. White pine trees growing as understories in stands 
of red pine are sometimes defohated by the larger larvae. Brown * 
stated that this species had become extremely abundant on red pine 
in parts of Quebec, Ontario, and southeastern Manitoba. Since 1934 
it has been defoliating red pine in the New England States, particu- 
larly in plantations. It seems, therefore, that the wholesale planting 
of red pine in pure stands has been favorable for the increase of this 
insect. This sawfly has one generation annually, although sometimes 
a small percentage of the prepupal larvae remain in a diapause in their 
cocoons for one or more years. The adults emerge in September and 
October, and the females deposit their eggs in slits cut in the needles 
of the current year’s growth. The winter is passed in the egg stage, 
and hatching takes place early in May. The larvae are gregarious 
and usually devour all the mature foliage on one branch before mi- 
grating to another. They become full grown in June, before the cur- 
> Brown, A. W. A. Annual report of the forest insect survey 1939. Canad. 
Dept. Agr. Ann. Rpt. Forest Ins. Survey 1939, 37 pp. 1939. [Processed. ] 
