BUREAU OF ENTOMOLOGY. 527 



pears. Owing to a lower mean temperature in this valley than in 

 many other fruit-growing regions, the period for the life cycle of the 

 codling moth was greatly lengthened, requiring from sixty to seventy 

 days, as compared with forty-nine to fifty-six, the time required in 

 the East. Spraying experiments for the codling moth in the Ignacio 

 Valley on pears were completed and gave very satisfactory results. 

 Plats of trees receiving two and three applications of arsenate of lead 

 in Bordeaux mixture gave, respectively, 87.G8 per cent and 97.10 per 

 cent of sound fruit, whereas on the unsprayed fruit trees only 40.85 

 per cent of the fruit was free from injury. There was a net gain in 

 favor of spraying of $1.49 per tree. A detailed report on the life 

 history of the insect in the valley and the results of the experiments 

 on pears has been submitted for publication. 



Demonstration spraying for the codling moth is being continued 

 during the season of 1910, as heretofore, in cooperation with the 

 Bureau of Plant Industry, mostly in connection with other investiga- 

 tions at the several field laboratories. This work is in progress on 

 pears in several localities in California and on apples in Michigan 

 and Virginia and in nine counties in eastern Kansas in cooperation 

 with the Kansas State Agricultural College. A detailed life-history 

 study of the insect is also being made in the Santa Clara Valley. 

 The demonstration spraying under way in Virginia, Arkansas, Penn- 

 sylvania, and Michigan during 1909 was successfully- completed and 

 gave uniformly good results. This work has been most heartily ap- 

 preciated by orchardists in the respective neighborhoods and seems 

 worthy of further extension. 



THE GRAPE EOOT-WOKM. 



The investigations of the grape root-worm, which have been in 

 progress since 1907, were continued over the growing season of 1909 

 as outlined in the report for that year. This investigation has been 

 very thorough both in tlie field and in the laboratory, and entirely 

 practical and economical measures have been fully demonstrated. 

 The work was therefore practically concluded in the fall of 1909 and 

 a full report has been submitted for publication. 



MISCELLANKOUS GRAPE INSECTS. 



In the course of the work on the grape root-worm much information 

 was accumulated on other grape insects. It was found tliat some of 

 these were of considerable importance, and upon the closing of the 

 grape root-worm studies specific attention has been directed to the so- 

 called rose bug and the grape leafhopper in the Erie grape belt. 

 Studies are also being made on a new insect enemy of the grape, 

 namely the grape bud gnat, which is assuming more and more im- 

 portance as an enemy of this crop. 



• 



ARSENIC ACCUMULATION IN SOILS IN SPRAYED WOODLANnS. ORCHARDS, AND 



VINEYARDS. 



The agitation concerning the danger of injury to orchard, sliade, 

 and other trees by excessive spraying with arsenicals, especially with 

 arsenate of lead, led to an examination of soils in sprayed orchards, 

 woodlands, etc., to determine if there were possibly an accumulation 



