308 



FRUIT INSECTS 



of the pit. In one orchard 80 per cent of the fruit was injured 



in this way. 



The adult sawfiies appear on the trees in early spring, and 



the female inserts her smooth, whitish, slightly kidney-shaped 



egg in one of the sepals or in the upper part of the calyx cup just 



before the blossoms open. The 

 eggs hatch in about five days, 

 or just after the petals have 

 fallen. After feeding for a short 

 time on the tissues surrounding 

 the egg cavity, the young larva 

 burrows to the center of the 

 fruit and eats out the kernel ; 

 the cherry soon withers and the 

 larva leaves it, only to enter a 

 second or third cherry in which 

 it feeds on the kernel or, after 

 t he stone is hardened, on the 

 pulp surrounding it. The larva 

 becomes full-grown in about 24 

 days, descends to the ground, 

 where at a depth of from 3 to 

 7 inches it constructs a tough 

 parchment-like cocoon, within 

 which it remains in the larval 

 condition, pupating some time 

 There is only one brood an- 



FiG. 264. — Nost of the cherry- 

 tree tortrix with empty pupa skins 

 protruding. 



after the winter rains set in. 

 nually. 



Control. 



No satisfactory means of control have been devised. 

 Thorough cultivation of the soil would doubtless destroy many 

 of the cocoons. Early in the morning the adults are usually 

 sluggish and can be killed with distillate-oil emulsion and to- 

 bacco extract as used against the pear thrips. Attempts to 



