REPOBT OF COMMITTEE ON PUBLICATION 237 



TWO DESTRUCTIVE GRAPE INSECTS OF THE 

 APPALACHIAN REGION. 



By FRED E. BROOKS, 



Entomological Assistant, Deciduous Fruit Insect Investigations, 

 United States Department of Agriculture. 



Several years ago, while the writer was connected with the entomological 

 department of the West Virginia Agricultural Experiment Station, he was 

 called upon to investigate severe injuries which were being done to grapes 

 in various parts of the State by the grape curculio, Craponius inaequalis 

 Say and the grapevine root-borer, Memythrus polistiformis Harris. The 

 accounts of these two which follow are based very largely on information 

 obtained at that time. Both species are prevalent in the Appalachian section 

 although neither is confined exclusively in its distribution to that region of 

 the United States. 



THE GRAPE CURCULIO. 

 Introduction. 



The Grape Curculio, Craponius inaequalis Say, is a small snout-beetle, 

 belonging to the family Curculionidae, whose larvae develop exclusively 

 within the fruit of the grape. The beetle uses its snout to puncture the skin 

 of partially-grown grapes for the purpose of depositing its egg within a small 

 cavity excavated from the pulp through the opening in the skin. The larva 

 hatching from the egg feeds on the pulp and seeds causing the fruit to drop 

 prematurely. 



In many parts of the Appalachian region, and also in some other sections 

 of the Mississippi Valley, the grape curculio is the most destructive of the 

 insects attacking the fruit of the grape. It is not unusual, in some localities 

 at least, for unprotected vines to lose 100 per cent of their crop from this 

 cause. In the region referred to, native grapes of several species abound 

 and there is no doubt that the wild fruit was the original food and breeding 

 place of the insect. The wild grapes are still attacked extensively and are 

 a source from which beetles are produced every year that fly to nearby 

 cutivated vines for the purpose of depositing eggs. Commercial grape grow- 

 ing is not an extensive enterprise at many points within the region under 

 special consideration but practically every home is supplied with vines to 

 furnish fruit for family use and there are numerous small vineyards the 

 products of which supply the local markets. Many of these growers find it 

 necessary every year to protect their crop in some way against partial or 

 entire destruction by this pest. 



Distribution. 



Most of the observations on the grape curculio made by the writer have 

 been in West Virginia, but the species has been recorded as occurring, also, 

 in destructive numbers in certain parts of Kentucky, Ohio, Illinois, Missouri 

 and Arkansas. For some reason, which has not been fully explained, the 



