Insect and Disease Control 227 



Preventive measures, which consist of so managing the 

 orchard that wounded and diseased areas through which 

 the larvae gain entrance will be avoided, may be expected 

 to be of value. 



California peach-tree borer {Sanninoidea opalescens) 

 This insect is also called the Pacific peach-tree borer. 



Appearance. 



In appearance this species is very similar to the more 

 common peach-tree borer previously discussed. The larvae 

 of the two species also look very much alike. 



Distribution. 



While this insect has been observed at various places in 

 Colorado, Nevada, Oregon, and California, it appears to be 

 noticeable as a serious peach pest, according to Moulton,^ 

 principally in the Santa Clara Valley in California and in 

 the parts of Alameda and San Mateo counties which lie 

 close around the southern arm of San Francisco Bay, where 

 it does considerable damage. 



Life history and habits. 



The life history of the California peach-tree borer is similar 

 to that of its near eastern relative. The adults are flying 

 from June to September, but they are the most numerous 

 during July and August. The period of egg-laying is coin- 

 cident with the period of activity of the moths. The eggs 

 hatch in about two weeks. A larva may enter very near 



1 Bur. of Ent. Bull. 97, Part IV, "The California Peach Borer," 

 p. 60. 



