BUREAU OF ENTOMOLOGY. 513 



will be obtained on its life history. Especial attention, however, is 

 being given to determining remedies for its control in \ineyards, and 

 to protect other crops that are subject to attack. The results of last 

 season's work were very encouraging, and the demand for informa- 

 tion on the subject by vineyardists rendered it desirable to furnish a 

 preliminary report, which was issued as Bulletin 97, Part III. 



The grape leafhopper, always present in vineyards, periodically 

 becomes abnormally abundant and destructive. This insect is now 

 much in evidence in vineyards in western New York and the Erie 

 Valley, and its injuries have been so severe as to require attention. 

 The work carried out during 1910 indicated that much benefit would 

 result by the timely use of strong nicotine sprays, and further ex- 

 periments are in progress with this and other washes during the 

 season of 1911. A preliminary report embodying the results of 1910 

 has been published as Bulletin 97. Part I. 



The grape berry moth, alluded to in former reports, is of irregular 

 occurrence in vineyards, though often very destructive. It has thus 

 been difficult to obtain suitably infested vineyards for proper experi- 

 mentation, though much information has been obtained on the life 

 history of the pest. In order to obtain final data on the use of cer- 

 tain sprays against this insect a badly infested vineyard in the neigh- 

 borhood of Sandusky, Ohio, is being used the present season for ex- 

 perimental work. In addition to the use of arsenicals, test is being 

 made of the possible value of nicotine sprays, which have recently 

 come into much use against nearly related insects in France. 



GRAPE PHYLLOXEBA INVESTIGATIONS. 



A detailed life-history investigation of the grape phylloxera, a 

 serious grape pest, was begun in the spring of 1911, with headquarters 

 at Walnut Creek, Cal. The study will include its complete life cycle 

 and methods and rate of reproduction, and especial attention will be 

 given to its means of dispersal under California conditions. Infor- 

 mation is also being collected on the history, present distribution, 

 destructiveness, and spread of the insect in that State. In coopera- 

 tion with the Bureau of Plant Industry, experiments are in progress 

 to determine the degree of resistance to the insect of roots of different 

 varieties of grapes. The plants are given colonies of the insect by 

 grafting into the roots pieces of infested roots, and the degree of 

 resistance will be learned by noting the behavior and multiplication 

 of the insects themselves, in addition to the condition of the vines, 

 with which phase of the subject the Bureau of Plant Industry is 

 concerned. 



PARASITIC AND PREDACEOUS INSECTS. 



As indicated in the report for 1910, it was planned to establish 

 a laboratory for the detailed study and rearing of parasitic and 

 predatory insect enemies of various deciduous-fruit insects. This 

 laboratory has been established and work has been begun. Especial 

 attention is being given to the study of the life liistories of certain 

 hymenopterous parasites of the codling moth and plum curculio and 

 also to the studv of life histories of certain coccinellid beetles preda- 

 tory on plant-lice and scale insects. It is hoped that these studies 



23165°— AGR 1911 33 



