138 



APPLIED ENTOMOLOGY 



Several hundred eggs are laid in this way and the "spot and crescent" 

 marks of the insect on small plums are familiar to plum growers. The 

 fruit often pours out gum at these places, probably in an attempt to 

 repair the injury. 



The eggs hatch in a week or less and the tiny whitish grub bores 

 through the flesh, and in stone fruits passes to the stone, around which it 

 feeds for about two weeks or until full-grown. It then leaves the fruit, 

 and as this in most cases has fallen before this time because of the injury, 

 the larva finds itself on escaping, on the ground. Into this it now burrows 

 an inch or two and pupates. About a month later the adult beetle 

 emerges, comes to the surface of the ground and attacks fruit for food, egg- 

 laying rarely if ever taking place at this season, and when cold weather 

 comes on it locates in some protected place for the winter. There is 

 accordingly, but one generation a season. 



FIG. 133. Apple showing injury by Plum Curculio in fall. (Modified from III. Agr. Exp. 



Sta. Bull. 98.) 



This insect, both by its feeding and egg-laying punctures, affects 

 the value of the fruit not entirely destroyed, not only in appearance but 

 by the opportunity these cuts afford for the entrance of the spores of 

 disease-producing fungi, and the destruction in the United States which 

 it causes has been estimated at over eight million dollars annually. 

 While the insect rarely succeeds in developing in the apple, the punctures 

 cause dropping of the fruit .or its malformation, and the production of 

 hard, woody places in the pulp. In the fall its feeding holes in apples 

 also cause much injury (Fig. 133). 



Control. No one method nor even all the methods of control taken 

 together will give entire freedom from this pest. A combination of 



