552 Report of the Entomologists of the 



Brief summary. — From the above we may briefly summarize the 

 life-history of this insect as follows: 



The case-bearers, not yet half grown when winter overtakes 

 them, hibernate on the twigs of the infested trees in silken cases 

 curved at the upper ends, securely fastened to the bark in a nearly 

 upright position, and usually near, but sometimes upon, the buds. 



About the time that the leaf-buds begin to swell they become 



active again. They attack the growing buds, gnawing through 



the outer covering to feed on the tender tissues beneath. Later 



in the season they feed on the young leaves, boring into them and, 



for a short time, making mines similar tQ those made by true leaf 



miners. They may also eat away the entire soft part of the 



leaves, frequently making holes clear through them. In doing 



this the caterpillars do not leave their cases, but project their 



bodies apparently as far as they can without losing hold of these 



protective coverings. They also attack the opening flower buds, 



boring into them as when attacking tlie leaf buds; the full blown 



« 

 flower; the mature leaves, eating nearly the entire leaf with the 



exception of the midrib and larger veins; and the fruit, into 



which they mine to a short distance beneath the skin, causing 



the fruit to become deformed. 



When ready to pupate the caterpillars migrate to the twigs 

 and attach their cases firmly to the bark. Pupation takes place 

 about the middle of May. Before this transformation is made, 

 however, the caterpillars turn around in their cases so that their 

 heads are toward the upper or curved end. 



The moths come forth early in June. The eggs are deposited 

 on the under sides of the leaves. They hatch in about ten days 

 or two weeks. The young caterpillars make small holes into the 

 leaves to enable them to feed on the tender pulp. Their cases 

 are made out of excrement and silk. During September tli(\v 

 migrate to the smaller branches and twigs to remain until spring. 

 Thus there is but one annual generation. 



Food plants. — The principal food plant of this insect is the 

 apple. It is known, however, to attack the pear and it is said to 

 attack the quince also. 



