32 MISC. PUBLICATION 273, U. S. DEPT. OF AGKICULTURE 



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, 

 Aviggly, 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) Cacoecia 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, (Eidia) Argyro- 

 taenia pinatuhana Kearf., {16) (fig. 41) is found in the Kocky Moun- 

 tain region, where it works on lodgepole pine. Usually it is not par- 

 ticularly destructive, but from 1921 to 1925., working in conjunction 

 with the lodgepole sawfly {NeodipHon hurkei Midd.), it destroyed 

 trees over a large area of immature lodgepole pine near West Yellow- 

 stone, in Montana. Since the cessation of the sawfly epidemic the 

 needle tier is still present in many areas, but has ceased to be 

 destructive. 



