29 G Report of the Entomologists of the 



DESCRIPTIONS AND LIFE HISTORY. 



llie egg. — The eggs are laid close together forming bands 

 ■which encircle the twigs. These bands or masses are abruptly 

 cut off on the edges and in this the egg-masses of this species 

 differ from those of the apple-tree tent-caterpillar. which are more 

 distinctly oval in outline. The frothy covering also differs 

 in color, being a dull gray instead of brown. As referred to 

 on a subsequent page there is a noticeable variation in their size 

 this year. Plate XXI, fig. 1, is from a photograph of two egg- 

 masses which differ greatly in size. The upper one has the more 

 typical shape. 



The eggs are placed on end side by side with somewhat more 

 regularity than those of the apple-tree tent-caterpillar. According 

 to Riley^'^ the female while depositing her eggs " stations herself, 

 for this purpose, in a transverse position across the twig." The 

 egg-laying habits of three females kept by the writer in the labora- 

 tory were carefully noted. The actions of these females indicate 

 that there may be exceptions to the habits observed by Dr. Riley; 

 for none of them placed themselves in a transverse position across 

 the twig, but stood lengthwise of it or nearly so, and moved 

 sidewise while depositing the eggs. When one row was finished 

 the next was immediately commenced. The eggs were placed 

 very close together. With each egg an abundance of frothy 

 glue was discharged, completely covering it and hardening almost 

 immediately. The females died within a few hours after complet- 

 ing oviposition. 



When first laid the eggs are nearly white but soon became a 

 dull gray. They measure on the average 1.2 mm. in length and 

 .Y5 mm. in diameter at the upper end, tapering slightly to the 

 lower end. They squarely cut off at the upper end but rounded 

 at the lower. The upper end is also distinctly margined with 

 white, the central area being darker and somewhat depressed. At 

 first this depression is very slight but gradually more pronounced 

 as the embryo caterpillar becomes fully formed. 



isAmer, Ent. and Bot., 2: 2G1. 



