46 Report of the Director. 



that was sprayed last year was again sprayed with this same poison 

 this season. Two applications were thoroughly made by a student 

 assistant, Mr. R. S. Woglum, with the result that it was difficult to 

 find any eggs laid by the beetles on the vines that were spraj'ed. 

 In connection with this work on the grape root-worm, I discovered 

 that its enemies are now taking an active part in the warfare against 

 it. In examining one vine at random in an infested vineyard, I 

 found 11 egg-clusters of this pest. In at least three of these egg- 

 clusters every egg contained a minute parasitic fly instead of the 

 embryo grape root-worm. This little enemy proved to be one of the 

 parasites which did gallant work in Ohio vineyards several years ago. 

 It is known as Fidiohia flavipes. As it lives in the eggs there is no 

 danger of checking its goodly work with any of the treatments for 

 controlling the pest by man. While I believe tliis parasite will be 

 an important factor in reducing the numbers of grape root-worms 

 below the danger limit in the Chautauqua grape region, I would not 

 advise any vineyardists to wait for its appearance or to let up a 

 particle in their warfare of cultivation and spraying for the pest. 

 Nature's insecticides are usually very effective in the long run, but 

 oftentimes too slow for man who is dependent on annual crops. 



Co-operative experiments. — This division purchased 650 pounds of 

 arsenate of lead for co-operative experiments with fruit-growers 

 during the season. About 400 pounds were used in spraying for the 

 grape root-worm in Chautauqua county, the results of which have 

 been given above. 



Six prominent fruit-growers co-operated in spraying with this 

 poison for the plum curculio. Some obtained quite marked results, 

 while others could see little difference between sprayed and un- 

 sprayed trees. Several plum-growers, however, are convinced that 

 they can control this pest by judicious applications of a poison spray 

 just after the petals have fallen and again a week or ten days later. 

 It requires very thorough and timely work. 



Two orchardists used this poison under my directions for the quince 

 curculio. The results were not so marked as last year, and in one 

 case they were vitiated by the jarring of the sprayed trees with a 

 " curculio-catcher." 



Last year's experiments against the rose-chafer were continued 

 this season. Two rose-growers and one vineyardist used the arsenate 

 of lead spray, and my assistant, Mr. Woglum, also sprayed some roses. 

 The insect appeared in large numbers over a wide territory in the 

 region along the southern shore of Lake Ontario, and in isolated 

 places in other parts of the state. In my spraying experiment the 



