THE BUTTERFLIES AND MOTHS 



117 



PEACH-TWIG BORER: WINTER BURROW 

 CUT OPEN 



The life history of this pest in California has been very 

 carefully worked out by the investigators of the State Ex- 

 periment Station. In brief it is as follows : Throughout 

 the fall and winter the small caterpillars are hidden within 

 curious cells that they make in the bark of the trees, es- 

 pecially in the forks of 

 the branches. These lit- 

 tle burrows are furnished 

 with a silken lining, and 

 are covered with a sort 

 of thatch made by fasten- 

 ing tiny bits of bark to- 

 gether with silk. Within 

 these hibernating cells, 

 the insects are protected 

 from most dangers. Early 

 in spring, the larvae become active and get ready to emerge 

 from their winter quarters by tearing away a part of the 

 protective covering. Finally they emerge and attack the 

 young buds, burrowing their way into the pith of the short 

 branches. They thus become twig borers, and often do 

 great damage. 



After a few weeks of this existence, they hide within the 

 bits of curled bark upon the trunk and larger branches, 

 where they change to pupae, generally very slightly shel- 

 tered by a few silken hairs. These pupae shortly change 

 again into adult moths, that lay their eggs on the bark of 

 the young twigs. These eggs soon hatch into tiny larvae, 

 which also become twig borers during the first weeks of 

 their life, usually upon a tree loaded with fruit. This brood 

 of worms lives as twig borers for only about three weeks. 



They then leave the twigs and burrow into the green 

 peaches, entering at the stem end and feeding freely upon 



