8 BULLETIN" 1066, TJ. S. DEPARTMENT OF AGRICULTURE. 



DISTRIBUTION. 



This species was described and named nearly a century ago by 

 Thomas Say. 7 Since Say's description was published entomologists 

 have from time to time collected specimens of the beetle, but no 

 data on the feeding habits of the species have found their way into 

 print. There are records of beetles being collected at Allegheny, Pa., 

 Topeka, Kans., Mendenhall, Miss., and Haulover, Fla. During the 

 present investigation the writer has collected the species at Harris- 

 burg and York, Pa.; Hagerstown, Cumberland, and New Windsor, 

 Md. ; Morgantown and French Creek, W. Va. ; Fincastle, Gala, Lick 

 Run, Marion, McDowell, Oak Eidge, Pulaski, and Radford, Va. ; and 

 Black Mountain and Hickory, N. C. 



FOOD PLANTS. 



No food plants of this curculio seem to be known other than the 

 black walnut (Juglans nigra) and butternut (J. cinerea) . Of these 

 two, the black walnut is much preferred, only one beetle of the species 

 having been obtained in extensive rearings from butternut. Hamil- 

 ton records taking the beetles by beating red oak sprouts, and the 

 present writer has collected them from' hickory trees growing close 

 to black walnut. The occurrence of the beetles on both the red oak 

 and hickory was probably accidental. 



NATURE AND EXTENT OF INJURY. 



Except for its different food plant, this species corresponds very 

 closely in all its activities as well as in appearance with the butternut 

 curculio. The adults feed on the tender shoots and leaf petioles and 

 make oviposition scars and feeding punctures in young black walnuts 

 similar to those made in butternuts by the other species. The larva? 

 develop in young black walnuts and cause the nuts to drop, usually 

 before they are half grown. The larvae are occasionally, but rarely, 

 found burrowing in the tender shoots of black walnut. 



In seasons when black walnut trees are bearing a light crop 

 of nuts a large percentage of the crop may become infested and 

 drop, but in years of heavy fruitage the curculios do no more than to 

 effect an unimportant thinning of the nuts. The following notes of 

 field observations indicate degrees of infestation such as were fre- 

 quently noted. On June 15, 1920, 17 newly set black walnuts were 

 picked from the lower branches of a tree growing in a parklike 

 woods near Cumberland, Md. Of these 17 nuts, 16 contained cur- 

 culio egg punctures and the other a feeding puncture. On the 16th 

 of the same month 50 per cent of the nuts on trees growing along 

 the highway at New Windsor, Md., were found infested. At French 



7 Sat, Thomas. Entomology of noeth America. (Leconte ed.) v. 1, p. 295. 1859. 



