Kew Yoek Agkicultukal ExrERiMENT Station. 297 



Small size of the egg-masses this year. — The egg-masses are said 

 to contain from 300 to 400 eggs. Rilej states^^ that he found the 

 number in five masses ranging from 3 80-41 G. Compared with 

 these figures the egg masses this year are very small as indicated 

 by the examination of a large number taken in the vicinity of 

 Geneva and from various sections of the State. They average only 

 half this size, containing, as a rule, but about 200 eggs. Many 

 were much smaller than this. As each female moth probably de- 

 posits all of her eggs in one mass this indicates an unusual falling 

 off in the number of eggs deposited. 



Time of egg laying and period of incubation. — In the latitude 

 of JSTew York the eggs are laid during the last week in June and 

 first week in July. ' 



The young caterpillars are fully developed within the eggs 

 before the summer is over, but do not escape until the following 

 spring. On August 29, an examination of eggs showed fully 

 developed caterpillars. Unlike the apple-tree tent-caterpillars 

 which were found bent backward in the eggs examined, all of 

 the caterpillars in about 100 eggs opened by the writer were bent 

 forward nearly double so that the head and posterior part of 

 the body came nearly together. 



The larva or caterpillar. — ■ The earliest caterpillars probably 

 appear with the first warm days of spring. This season they 

 were found about Geneva during the last week in March. The 

 period of hatching, however, extends over a month or more, as 

 young caterpillars that had not yet passed their first molt were 

 found at Geneva as late as May 26, and colonies of newly hatched 

 caterpillars were found at various times between, while by May 22 

 large numbers of caterpillars had reached nearly full size. 



Growth. — Under normal conditions the caterpillars are full- 

 grown within about six weeks, but in case they hatch before the 

 leaf buds of their food plants have burst, their development is re- 

 tarded by lack of food. Cold or iuplonicnt weather soon after the 



HAmer. Ent. and Bot., 2: 2(11. 



