THE LARCH CASE-BEARER 49 



says that when the larvae have consumed all the needles on one branchlet 

 they lower themselves down to others by means of a silken thread. He 

 also noted that they devoured the flowers of the larch. 



Apparently the larva lives in this enlarged case during the remaining 

 time of its growth and pupates within it. 



The larva 



The larva is dark reddish brown and, when full-grown, about one fifth 

 of an inch in length (4^ to 5 mm.). The head is black, and the thoracic 

 shield is black but divided along the middle. The last segment of the 

 abdomen bears a black plate on the dorsal side. The anterior pairs of 

 prolegs are small and each one is furnished with a circle of minute hooks; 

 while each of the posterior prolegs bears a half circle of strong hooks point- 

 ing forward, by which the larva clings most tenaciously to its case. The 

 end of the caudal segment of the abdomen is beset with strong chitinized 

 setae pointing straight caudad. 



The favorite locations for the larvae to attach themselves when ready 

 to pupate seem to be at the bases of the short side branches and in the 

 center of the leaf whorls. In Fig. 13 is shown a cluster of four pupae 

 at the base of a short side branch. The pupal stage lasts fourteen to 

 twenty days. The pupa is small and brownish black, with no char- 

 acteristic markings. 



The moth 



The moths were appearing by May 24 in 1911 and were abundant from 

 that time on. The moth is small, silvery grayish brown in color, with 

 no conspicuous markings. Both pairs of wings are narrow, especially 

 the hind wings, and fringed with long, slender scales (Fig. 6). The wings 

 expand about one third of an inch. The moths are active during the 

 daytime and when at rest they alight on the stems or leaves, with the 

 wings closely folded along the body and the antennae projecting straight 

 forward. 



Within a few days the moths pair, and in a week to ten days from 

 emergence begin laying their eggs. 



The egg 



The eggs are small, but plainly visible to the unaided eye, and in shape 

 they resemble an inverted teacup. Each egg is conspicuously marked 

 with twelve to fourteen ridges radiating down the sides from the apex. 

 The eggs are conspicuous objects on the green leaves of the larch, being 

 cinnamon-rufous in color and standing out clearly in contrast to the green. 

 They seem to be laid indiscriminately on the upper and under sides of 



