138 LASIOCAMPIDS. 
The breeding-cages were kept in different parts of the same 
building. In one case the caterpillars were fed with leaves 
moistened with the crushed substance of diseased caterpil- 
lars, and soon afterwards the disease showed itself by killing 
nearly all the caterpillars in that cage; the worms in the 
second cage were fed on leaves not so prepared and all 
matured and formed moths. Equally good results were ob- 
tained with a disease destroying the worms so injurious to 
cabbage, and both cases show that under certain conditions 
much good can be done by gathering diseased caterpillars 
and by bringing them in contact with healthy ones. 
After mating the females deposit their eggs (about 300: 
in number) in a belt or ring around the twigs of plum, 
cherry, shadberry, apple or a few other trees. This takes 
place early in July. These egg-masses are coated with a 
thick glue which serves as a protection against moisture 
and, perhaps, against the cold weather of autumn, winter 
and spring. Very likely this glue is a non-conductor of heat; 
at all events theeggs do not usually hatch until the following 
spring, even if kept in warm rooms. These rings of eggs are 
readily seen at a time when all the foliage has disappeared 
from the trees, and they should be removed at that time, 
which is easily done. Fig. 136 shows a ring of eggs; also 
two adult caterpillars and a cocoon. 
About the time that the buds begin to swell in the 
spring (about the middle of April in Minnesota) the eggs 
hatch, and the young caterpillars select some fork of a twig 
where they form a small nest for themselves. By selecting a 
fork they can utilize the twigs as tent-poles, around which 
they build a nest with several openings or doors. Here the 
colony rests, either inside or on the outside of the tent. As 
- long as the caterpillars are still soft and tender they are 
most frequently found inside their house, and only during 
the warmer portion of the day do they bask in the sun upon 
its outside. As the caterpillars grow they add to this tent 
untilit becomes a very bulky affair partly filled with excrement. 
