 F-486626 
Figure 182.—Large pines heavily defoliated 
by the loblolly pine sawfly, Neodiprion 
taedae linearis. 
In the Lake States, winter is spent as prepupae in cocoons in the litter or top- 
soil, and pupation and adult emergence occur in early to late spring. Eggs are 
laid in the current year’s needles, one to three eggs per needle, during June or 
July. The larvae are gregarious and feed primarily on old foliage, usually on ex- 
posed trees during July and August, until they become mature and drop to the 
ground. There is one generation per year (80). 
Numerous outbreaks have occurred at about 8-year intervals in jack pine stands 
in Ontario and Quebec, with foci in poorer jack pine sites on outwash plains (S03). 
Heavy tree mortality occurred in overmature stands and practically all surviving 
trees over many hectares remained stag-headed for several years. A sawfly popula- 
tion simulation model for such stands has been developed (804). Some of the most 
severe infestations in the Lake States have occurred in jack pine plantations and 
windbreaks. Aerial application of a nuclear polyhedrosis virus spray has provided 
satisfactory control for at least | year in tests conducted in Quebec (/095). 
The red pine sawfly, N. nanulus nanulus Schedl, occurs in the Northeastern 
States west to Minnesota and in adjacent Canada. Its favored hosts are red and jack 
pines, but it also feeds on eastern white, Japanese red, and Swiss mountain pines. 
Full-grown larvae are dull grayish-green to black on top, greenish white beneath, 
and about 18 mm long. The head is black and two olive-green stripes run down the 
back to a darker area near the rear end. There are two longitudinal dark stripes on 
each side, with the upper one a little darker than the lower one. 
389 
