70 Journal New York Entomological Society. [Voi. xxx. 



The larva, when first hatched, is black or brownish with a black 

 head, hairy and 5 mm. in length. The full-grown larva measures over 

 two inches in length and is greenish in color. 



The Adult. Color brownish-gray, antennse yellow, biserrate a little 

 longer than the thorax. Thorax clothed with short soft hairs. Ab- 

 domen above dark brown, sides grayish, apex tufted extending beyond 

 the wings. Wings semi-transparent. Forewings with two indistinct 

 oblique wavy brownish bands, the exterior one paler, space between the 

 bands sparsely clothed with white scales, a small distinct black spot on 

 the discal nervure. Hind wings with an indistinct cloudy band, 

 broader at the interior margin, gradually tapering to the exterior. A 

 pale brownish spot on the disc. Base of wings clothed with pale 

 pinkish hairs, cilia at the extremity of the veins whitish. Underside 

 brownish-gray, tinged with pink, the discal spots more distinct than 

 on upper surface. Length of body 5 i-35 c^ i-2 inches, expanse 5 34 

 (^ 2.y inches. 



Life History and Habits: 



Egg deposition occurs over a period of two to three weeks in July ^ 

 and the young larvae begin to emerge the last week in August and con- 

 tinue emerging for about two weeks. The larvae leave the Q^g by 

 gnawing out one end of the shell. The larvae are voracious feeders 

 and rapidly defoliate the pines. Complete data on life history has not 

 yet been secured. The adults appear in late June and early July. The 

 fact that no adults were noticed in 1919 and no grown caterpillars 

 appeared in 1920 leads to the belief that the life cycle covers a period 

 «of two years. 



Economic Importance: 



During the summer of 1919 the larvae appeared in great numbers 

 :near Calimus Butte on the Klamath Indian Reservation and practically 

 istripped the needles from all but the largest yellow pine (Pinus 

 ■ponder osa) trees on ten sections lying in Twp. },2> S., R. 10 E., Twp. 

 36 S., R. 12 E., and Twp. 31 S., R. 9 E. During the summer of 1920 

 no caterpillars appeared, but thousands of the moths were present to 

 deposit their eggs upon' the trunks of the trees and even upon the 'debris 

 of the forest floor. After mating and depositing eggs the adults die, 



1 On Klamath Indian Reservation in Oregon. 



