454 FRUIT INSECTS 



root and completes its growth the following spring. The 

 larvae become mature in late June and early July of the 

 second year after hatching from the egg. They are then 

 about one and three fourths inches in length and whitish 

 in color, with a brownish head. When about to pupate, the 

 larva leaves its burrow in the root, ascends almost to the sur- 

 face of the ground and there constructs a silken cocoon in the 

 outer layers of which are incorporated particles of earth and 

 excrement. The pupal period lasts four or five weeks. When 

 about to transform, the pupa works itself out of the cocoon so 

 that its anterior end is brought to the surface of the ground 

 and the moth is enabled to escape without injury to its wings. 

 The moths usually emerge in the morning hours, the sexes 

 mate the afternoon of the same day and the female begins to 

 lay eggs the following day. They lay most of their eggs in 

 about a week and die in ten days or two weeks. 



Living underground in the roots at some distance from the 

 base of the vine for the greater part of its existence, the grape- 

 root borer may do serious injury to the vines and cause con- 

 siderable loss without attracting the attention of the vineyardist. 

 The control of this insect is not easy. Digging out the borers, 

 as is done with its near relative, the peach-tree borer, is here 

 impracticable, because as a rule they are found far out in the 

 roots where it would be impossible to reach them without 

 moving a large quantity of earth. 



Much may be done, however, to lessen the numbers of moths 

 by frequent shallow cultivation of the vineyard from the middle 

 of June till the middle of July while the pupae are near the sur- 

 face. Not only will cultivation at that time either bury or 

 destroy many of the pupae, but it will tend to produce a vigorous 

 condition of the vines and render them more resistant to borer 

 attack. 



Reference 



W. Va. Agr. Exp. Sta. Bull. 110. 1907. 



