18 STATE POMOLOQICAL SOCIETY. 



glutinous covering which the young feed upon till they gain suffi- 

 cient strength to make a move, when they crawl down the branch, 

 spinning a fine silken thread from the spinneret in the mouth. 

 Having arrived at a fork of a limb they stop, and erect a kind of 

 tent for their future residence, by crawling around the spot and 

 spinning their threads in every direction. 



As the caterpillars grow larger the original tent becomes too 

 small for them all, and large numbers of them, as they return from 

 their foraging expeditions, rest side by side upon the outside of 

 the tent and completely cover it over, while others coming in 

 wander about and over the sleeping ones, looking for some place 

 of repose, still spinning their silken threads, till at last a complete 

 scaffolding is formed above those first in, and in this way another 

 story is added to the tent. 



In all cases where I have raised tent caterpillars in confinement, 

 they have taken two meals a day, provided the weather was clear 

 and warm, one about the niiddle of the forenoon the other about 

 the middle of the afternoon. Some, however, have stated that 

 they take a third meal sometime in the night, but I think this 

 rather doubtful. From the observations of others, and from my 

 own experiments, I am led to conclude that each caterpillar will 

 consume on an average about two apple leaves a day, and as each 

 nest contains about three hundred caterpillars, there would be six 

 hundred leaves destroyed each day by the inhabitants of a single 

 tent, a drain which no tree can sustain for any considerable length 

 of time without great injury ; and when there are several tents 

 upon the same tree the injury is so much the more increased. 

 After the caterpillars have attained their full growth, they lose 

 their social habits, and wander off to find suitable places in which 

 to spin up their cocoons, which are oblong-oval in form, and of a 

 light yellowish white color, and attached horizontally to the under 

 side of fence rails, or other protected places. They remain in 

 these cocoons about three weeks, after which the perfect insects 

 come out, the sexes pair, and the females lay their eggs upon the 

 twigs of the trees, when the work of that generation is done, and 

 the moths very soon die. 



There are three measures which I can confidently recommend 

 whereby these insects may be held in check, and the trees saved 

 from ruin : 1. Burn all the cocoons which may be found, except 

 such as contain other insects as parasites. Preserve these care- 

 fully, and allow the parasites to mature and escape that they may 



