litter or topsoil. Pupation occurs in October or November and the adults emerge 
soon thereafter. Eggs are laid in slits cut into the needles, usually 2 to 10 per needle. 
Each female lays from 90 to 120 eggs, often all in the needles of one twig (/25/). 
This sawfly is found chiefly on medium-size or large trees in forest stands. 
Several outbreaks have been recorded. One, which lasted four seasons, spread over 
an area of about |.2 million hectares in Arkansas before it subsided. Trees suffering 
spring defoliation exceeding 75 percent per tree have shown an average net growth 
loss of 51 percent | year following defoliation and 29 percent the second year (fig. 
182). Important natural control factors are a polyhedrosis virus disease, cold, rainy 
weather in the spring, and two larval parasites, a bombyliid, Villa sinuosa sinuosa 
(Wiedemann), and the ichneumonid, Exenterus nigrifrons Rohwer (256, 1251). 
Neodiprion warreni Ross is found in the Southeastern States from Arkansas into 
north Florida. Known hosts include spruce and shortleaf pines. Mature feeding 
larvae have a shiny black head and broad black subdorsal, lateral, and sublateral 
longitudinal stripes. Spaces between stripes are reduced to narrow, pale lines. 
Mature, feeding larvae have been collected during October in Arkansas and Flor- 
ida. 
The Swaine jack pine sawfly, NV. swainei Middleton, one of the most important 
of the pine-infesting sawflies in eastern Canada, is known to have been present in 
the Lake States since the early 1950’s. It is now widely distributed in the Upper 
Peninsula of Michigan, and in north-central Minnesota and Wisconsin. Jack pine is 
its favored host, but red, Scotch, and eastern white pines growing in close prox- 
imity to heavily infested jack pines are also subject to defoliation by migrating 
larvae (/333). Full-grown larvae differ in color in different portions of the infested 
region. Those found in the Lake States have bright-orange heads and yellow bodies 
and there usually are two longitudinal, pale stripes on each side. Bright-yellow 
specimens without stripes are found occasionally. 
F-486627 
Figure 181.—Larvae of the loblolly pine sawfly, 
Neodiprion taedae linearis. 
388 
