4 Department Circular 288, U. S. Dept. of Agriculture. 



The color in these later instars is extremely ^-a^iable, being pale yellow, gray, red- 

 dish brown, or mouse color, and some few present mixtm-es of colors. These' colors 

 change with the molts and do not seem to be correlated with age or food plants. 



THE COCOON. 



The cocoons are spun on the trunk or small branches and occasionally on the 

 leaves of the host trees. The first silken structure (Fig. 6) is elongate oval, and 

 within this is formed the more dense and tough urn-shaped cocoon with its char- 

 acteristic hump in the middle over the thoracic region and beautifully con- 

 structed beveled-edge operculum (Fig. 7). Practically all of the long hairs are shed 



Fig. 3. — Eggs of the puss caterpillar oa leaf, covered with hairs frora body of moth. 



by the larva as it spins and are interwoven with the silk, thus giving the cocoon 

 nearly the same range of color as shown among the caterpillars. The ventral side 

 of the pupa is shown in Figure 8, 



LIFE HISTORY AND SEASONAL HISTORY.^ 



The insect spends the whiter in the Larva sta^^e witliin the cocoon. 

 Pupation takes place in the early spring and the adults emerge in 

 April, May, and June. The moths in emerging from the cocoon 

 often leave the exuviae projecting from the operculum (Fig. 9). 



« In the life-history work carried out in 1914 the writer was materially assisted by W. E. Dove. 



