576 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



The Plum Curculio * 



Throughout the States east of the Rocky Mountains, the Plum 

 Curculio is one of the worst pests of the common stone and pome 

 fruits. Its larva is the common white " worm " found in peaches, 

 plums, and cherries, while apples and pears are scarred and gnarled 

 by the feeding and egg punctures made by the adults. It is a 

 native insect which breeds on wild plums, wild crab-apples and 

 hawthorns. The adult is a thick-set snout-beetle about one- 

 quarter inch long, brownish in color, marked with gray and 

 black, and with four black ridged tubercles on the wing-covers. 



FIG. 431. The plum curculio (Conotrachelus nenuphar Herbst.): a, larva; b, 

 beetle; c, pupa all much enlarged. (After Chittenden, U. S. Dept. Agr.) 



The larva is a footless, cylindrical, whitish grub, about one-third 

 inch long, with a small brown head, and usually lies in a curved 

 position as in Fig. 431. 



Life History. The beetles hibernate under grass, leaves, and 

 other trash on the ground in or near the orchard, or in neighboring 

 woodlands, and commence to emerge just before the fruit trees 

 bloom in the spring. They feed somewhat on the buds, unfolding 



* Conotrachelus nenuphar Herbst. Family Curculionidce. See C. S. 

 Crandall, Bulletin 98, 111. Agr. Exp. Sta.; S. A. Forbes, Bulletin, 108, ibid.; 

 J. M. Stedman. Bulletin 64, Mo. Agr. Exp. Sta.; E. P. Taylor, Bulletin 21, 

 Mo. State Fruit Exp. Sta.; A. L. Quaintance, Yearbook U. S. Dept. Agr., 

 1905, p. 325; Circular 120, Bureau of Entomology, U. S. Dept. Agr. 



