INSECT ENEMIES OF WESTERN FORESTS 



83 



The adult needle tier is a small brownish-gray moth with darker 

 patches and bands on the forewings and a wing expanse of about 

 one-half inch. Eggs are laid during the latter part of June and 

 early in July in groups of 2 to 30, with an average of about 10 per 

 cluster, on the concave side of loclgepole pine needles. These eggs 

 hatch in 7 to 10 days, and the young larvae crawl over the foliage 

 until needles satisfactory for their attack are found — usually those 

 of the current year's growth. Each larva then enters a needle by 



Figure 40. 



-The sugar pine tortrix (Cacoecia lamhertiatiae) and its damage to sugar 

 pine terminals. 



biting a circular hole near the tip and spends from 2 to 3 weeks in 

 feeding on the interior tissues. The inside of the mined needle 

 is lined with a papery, wdiite, closely woven web to form a tube. At 

 an early period in the growth of the larva or when it becomes too 

 large for the mined needle, several other needles are drawn to it and 

 bound together so as to form a new and larger tube (fig. 41, B). 

 This tube is also lined with a papery white web and has an opening 

 at each end, that allows the insect to leave quickly when disturbed. 

 Often a caterpillar will abandon one tube and form a new one. Feed- 

 ing takes place within the tube, and as the caterpillar becomes larger 

 the tube is extended farther down the needles, often to the base. 



