82 MISC. PUBLICATION 273, U. 8. DEPT. OF AGRICULTURE 
The small moths, that are gray or dappled with brown, black, 
orange, and white, and have a wing expanse of three-fourths of an 
inch, appear during August and September, mate, and lay their eggs 
on the under side of the needles. The eggs remain unhatched during 
the winter, but in the spring the small, pale caterpillars appear and 
start feeding on the new foliage of opening buds. They work in 
much the same way as the spruce budworm, boring into and feeding 
on the opening buds and webbing the new needles together to form 
a protective case within which they feed. As they develop they 
become bright green, and the head turns black. If disturbed they 
actively wiggle backwards and drop to the ground by silken threads. 
They reach full growth by the last of July, at which time they are 
a trifle more than a half-inch in length and may have brown heads. 
Usually they confine their work to the new growth, but if they are 
numerous the larger caterpillars will leave the nests and feed upon 
the older needles, bringing about complete defoliation. Pupation 
takes place within a web made among the dead needles and frass on 
the twigs. Prior to emergence, the pupa, which is dark reddish 
brown with a greenish tint, works partly out of the web so as to 
allow the moth freedom to emerge. There is but one generation a 
year. 
A small amount of feeding by the black-headed budworm takes 
place every year, but it is scarcely noticeable. When an attack is 
heavy toward the end of July, the forest takes on a reddish-brown 
appearance. This is due to the dying of the new foliage that is 
partly eaten but remains attached to the twigs by the webs of the 
caterpillars. Their presence can be confirmed by finding the small, 
wiggly, green caterpillars, or the brown pupae, among the webs at 
the tips of the branches. For some reason heavy defoliation by 
this insect does not prove so disastrous to the trees as similar work 
by other species, such as the hemlock looper. Even repeated heavy 
defoliations of western hemlock for 2 or more years have not caused 
any serious loss of timber. 
The larvae of the black-headed budworm are parasitized by 
numerous insects and are affected by a wilt disease. These agencies 
become dominant and bring outbreaks under control within 2 or 3 
years. 
' The sugar pine tortrix (Tortrix lambertianae Busck) (fig. 40) is 
at times very destructive to the new buds and pollen bodies of sugar 
pine, killing as much as 90 percent of the new growth on the trees. 
The caterpillars feed in colonies within a web on the terminal shoots 
and transform to adults in July. The adults are speckled tan to 
golden moths with a wing expanse of about seven-eighths of an inch. 
The lodgepole pine needle tier or pine tube moth, Lula (Argy- 
rotaenia) pinatubana Kearf., (16) (fig. 41) is found in the Rocky 
Mountain region, where it works on ledgepole pine. Usually it is 
not particularly destructive, but from 1921 to 1925, working in con- 
junction with the lodgepole sawfly (Neodiprion burkei Midd), 
it destroyed trees over a large area of immature lodgepole pine near 
West Yellowstone, in Montana. Since the cessation of the sawfly 
epidemie the needle tier is still present in many areas, but has ceased 
to be destructive. 
