SB 

 818 

 C578 

 ENT 



Jo. 73. 



lited vStates Department of Agriculture, 



BUREAU OF ENTOMOLOGY, 



L. O. HOWARD. Entomologist and Chief of Bureau. 



THi: PLUM CURCl LiO. 



(('(jiiofrdcJicliis iH'iniiihur llerhst. i 



By Fred .Tohxsox .iiid A. A. (Jiuaii.t. 

 E)i(j(i(/r(l ill Jh'cid loiis-l-'i-iiif I nsrct J ii rcstii/iifionK. 



IXTKODUCTIOX. 



The small, crescent-shaped punctures so commonly found on jDlums 

 and other stone fruits in orchards east of tlie Ivocky Mountains are 

 made by a small snout-beetle of rough sculpture, known as the plum 

 curculio. These beetles issue from their winter quarters about the 

 time the trees are in 

 bloom, and feed on the 

 tender foliage, buds, and 

 blossoms. Later t h e v 

 attack the newly set 

 fruit, cutting small cir- 

 cular holes through the 

 skin in feeding, while 

 , the females, in the oper- 

 ation of egg 1 a y i n g , 

 make the crescentic cuts 

 so characteristic of this 

 species. The egg, de- 

 posited under the skin 

 of the fruit, soon hatches into a very small whitish larva or grub, 

 which makes its way into the flesh of the fruit. Here it feeds greedily 

 and grows rapidly, becoming, in the course of a fortnight, the fat, 

 dirty white " worm '' so well known among fruit growers. 



The plum curculio is a native of North America and for more than 

 one hundred and fifty years has been known as an enemy of stone 

 fruits. Our early horticultural literature abounds with references to 

 its depredations. In more recent times the great increase in plantings 

 of fruits, brought about to sui)i)ly the increa.sed demand, has per- 

 mitted it to become much more abundant than formerly, and the plum 

 curculio constitutes, at the present time, one of the most serious 

 insect enemies of orchard crojjs. 



This species is quite generally distributetl over the United States east- 

 ward of about the one hundredth meridian, its range extending from 

 southern Canada to Florida and Texas. Westward of the States 

 28804— No. 73—07 m 



Fig. 1. — The plum curculio {Omotrachelus nenuphar): a, lan'a; 

 b, adult; c, pupa. Much enlarged (hair line to right of b 

 indicates natural length of adult). (From Chittenden.) 



