INSECTS INJURIOUS TO PEACH, PLUM AND CHERRY 581 



FIG. 512. Peach twig-borer in winter 

 quarters: a, twig, showing in crotch 

 minute masses of chewed bark above 

 larval chamber; b, same, much en- 

 larged; c, larval cell enlarged; and 

 d, larva very greatly enlarged. (After 

 Marlatt, U. S. Dept. Agr.) 



the West, those of the second and third attacking the fruit, the 

 later varieties being the worst injured. According to Professor C. 

 V. Piper, the larva enters the peach at the stem end, usually bor- 

 ing into the pit, the seed of which 

 it seems to prefer, usually caus- 

 ing the stone to split as the fruit 

 ripens; or simply the flesh may 

 be tunnelled, depending on 

 whether or not the stone is hard 

 when the fruit is attacked. In 

 California, according to Clarke, 

 the larva usually enters the fruit 

 along the suture at the stem 

 end, and excavates a chamber 

 beneath the skin, which black- 

 ens and shrivels somewhat, af- 

 fording entrance to organisms 

 of decay. In the ripe fruit the 

 larvae frequently make their way to and around the stone, which, if 

 split, may be entered and the seed feed upon. . . . Early in the 



fall, about September 1, in 

 California, the very young 

 larvae from eggs of the last 

 generation of moths construct 

 their hibernation cells in the 

 soft tissue of the crotches of 

 limbs, where they remain un- 

 til the following spring, thus 

 spending some six months in 

 this condition." Quaintance. 

 Control. By spraying dur- 

 ing the winter, or preferably 

 after the buds have swollen 

 in the spring with kerosene 

 or distillate-oil emulsion, the 

 oil is absorbed by the cast- 

 ings at the mouth of the burrows of the hibernating larvae, and 

 thus penetrates the burrows and kills the larvae. Lime-sulfur wash 



FIG 513. The peach twig-borer: a, new 

 shoot of peach withering from attacks 

 of larvae; 6, larva enlarged; c, pupa, 

 enlarged. (After Marlatt, U. S. Dept. 



