12 
ment bound together with silk. Data as to how long it takes the larva 
to become full grown were secured. However, the number of experi- 
ments and the number of larvae were small and more work must be 
done before a good average can be given. The shortest time was 
fourteen days and the longest twenty-five, with twenty-one days as an 
average. When the larva is full grown it eats its way to the outside 
of the apple, but remains within, plugging the hole with frass. In 
a day or so this obstruction is pushed out, and the larva crawls out 
and immediately seeks a place in which to spin its cocoon and complete 
its transformation. 
The effect of this insect on the apples and pears is such that the} T 
ripen prematurely and fall from the tree, being worthless for com- 
mercial purposes. 
The larva makes its way from the apple to the place of spinning its 
cocoon in one of three ways. Most commonly it simply crawls from 
the apple to a twig, thence to branch, and thence to the trunk of a 
tree. Experiments conducted b} T Professor Aldrich upon trees with 5 
bands show that twice as many larvae spin their cocoons under the top 
band as under any intermediate band, and the next highest number 
was found under the bottom band. In case of windfalls, the larvae 
leave the apple and crawl to a suitable place along the ground. In a 
few cases the larvae drop from the tree to the ground by a silken 
thread. Many of these threads have been noted by the writer. 
The larva? spin their cocoons in a variety of places. Those noted are 
as follows: Under loose pieces of bark (PI. Ill, fig. 2) on rough trees; 
in the cracks in the crotches of trees; in cracks or holes in the tree 
trunks; under splinters on fence posts (PI. II, and fig. 1 of PI. Ill); 
in the rough bark of adjacent trees- (PI. Ill, fig. 2); in any kind of 
rubbish about the trees; under anything lying against or upon the 
trees; in cracks in the dry earth about the trees; and, in some few 
cases, in dried fallen apples. The place of first choice under normal 
conditions is under the loose bark, in the crotches, or in the holes or 
cracks in the tree. When the tree is smooth and the earth is dry we 
sometimes find a considerable number of cocoons in the cracks in the 
earth. 
In general the larva selects a dry, tight place, and it may gnaw out 
a hole in the bark and incorporate the pieces in the cocoon. Many 
times a silk tube 2 or 3 inches in length is found with a cocoon at one 
end. Evidently the larva did not find a place tight enough and con 
tinued spinning until such a place was made. In these cases a cap of 
silk is found. Cloth bands furnish a place for spinning cocoons most 
acceptable to the larvae. 
The larva spins its cocoon in about two days. The cocoon is com 
posed of a single thread of silk, a product of the silk glands common 
