K'ew YoitK Agkicultukal Experiment Station. 303 



closely resemble those of the apple tree tent-caterpillar described 

 oil pages 286-287 of Bulletin 152 of this Station, bnt are some- 

 what more loosely woven and have less of the yellowish powder. 

 In the vicinity of Geneva the spinning of the cocoons began last 

 season about the last week in May and continued until the middle 

 of July. 



Although it has been considered one of the characteristics of 

 this species to utilize a leaf in making the cocoon there w^ere many 

 exceptions last season, for they were found in great numbers upon 

 the fences and out-buildings and even upon the ground, where no 

 leaves were to be had to aid in their construction. This may 

 have been in part due to a scarcity of foliage in the woodlands 

 where the trees had been entirely stripped. In sections where the 

 caterpillars were less common, most of the cocoons were formed in 

 the leaves, the leaf or leaves being brought around the cocoon as 

 shown at Plate XXI, fig. 3. This picture shows a cocoon partly 

 enclosed by two elm leaves held in place by the numerous threads 

 of silk attftched to them. Some of the forest tent-caterpillars kept 

 in the breeding cages showed a tendency to forsake this habit; for 

 out of about 150 over half spun their cocoons upon the sides of the 

 cages, the remainder utilizing the leaves that were there in abun- 

 dance. ]\[ost of these caterpillars spun their cocoons during the 

 night, but a few kept in a darkened room began during the latter 

 part of the afternoon. These were observed to require between 

 five and six houi's to complete the work. After completing the 

 cocoon the imprisoned catcrjiillar molts once and then passes t;) 

 the pupa stage. 



The pupa. — Both male and female pupse are reddish-brown in 

 color. The former measures about five-eighths of an inch in length 

 and the latter three-fourths. 



Moths: time of appearance; habits. — -Last spring in the vicinity 

 of Geneva the moths were occasionally seen by June 20. A 

 large number of the cocoons gathered from various parts of tlie 

 State where the caterpillars were very abundant furnish interest- 



