BUBEAU OP ENTOMOLOGY. 511 



history investigations alluded to in my last report as in progress in 

 northwestern Pennsylvania have been completed and the results 

 reported upon in Bulletin 80, Part VT. Additional studies of this 

 character will be undertaken another season, if practicable, in the 

 Southwest, perhaps in Arizona or New Mexico, and in the Southeast, 

 possibly in northern Georgia. It is also hoped to make arrangements 

 for similar work in some of the important fruit districts in the arid 

 valleys of the West, where conditions are such that the pest is espe- 

 cially troublesome. 



The experiments in progress during 1910 to test the relative merits 

 of the one-spi*ay versus the usual schedule of applications in the 

 control of the codling moth did not, on account of the comparatively 

 little injury in the orchards treated, furnish marked results, so 

 that this work was continued, beginning with the spring of 1911. 

 The experiments are in progress in Kansas, Delaware, West Vir- 

 ginia, and Michigan, and it is hoped that the results of this season's 

 work will permit of final conclusions on the subject. 



In conjunction with the one-spray work, demonstrations in spray- 

 ing are in progress in the localities mentioned, designed especially 

 for the benefit of orchardists. Careful records are being kept of the 

 costs and benefits of the work, so that results may be stated in terms 

 of dollars and cents. The field work also includes the use of several 

 different arsenicals that further information may be obtained regard- 

 ing their comparative value. 



The growing importance of the apple-growing industry through- 

 out the Appalachian Mountain region, especially in the Virginias, 

 North Carolina, and Marylnnd, has rendered desirable more accurate 

 information relative to the variations in the life and habits of the 

 codling moth due to location, especially as bearing on the times when 

 spraying applications should be made to secure the maximum benefit. 

 A thoroughgoing study of the insect throughout this region was 

 therefore undertaken, beginning with the spring of 1911, and the 

 work assigned to two men, with headquarters in West Virginia. 

 Careful records are being obtained in orchards in both valley and 

 mountain regions, and in the latter case from some localities repre- 

 senting considerable altitudes. 



The life-history studies of the codling moth in the Ignacio Valley 

 in California, and the spraying experiments in progress on pears, 

 mentioned in the last report, were completed, and the work reported 

 upon in Bulletin 97, Part II. The results obtained show that it is 

 entirely practicable largely to prevent loss of pears from this insect 

 by timely spraying, and recommendations of the bureau have already 

 been largely adopted by pear growers. 



THE PLUM CURCTTLIO. 



The spraying demonstration and experimental work for the plum 

 curculio in the South in progress during 1910, in cooperation with 

 the Bureau of Plant Industry, was successfully completed and the 

 results given in Farmers' Bulletin 440, issued in March, 1911. The 

 results obtained were quite as favorable as those secured during the 

 previous year, and show conclusively the entire practicability of 

 controlling the plum curculio and certain important peach diseases 

 bj' the use of a combined spray of arsenate of lead and self-boiled 



