The Currant Fruit Fly. 233 



dead fruit fly was found. The leaves showed no evidence of 

 burning. 



An experiment was performed in the field to compare the 

 attraction of the adult for the poisoned bait applied to the lower 

 tranches of a red currant bush with honey-dew of plant lice 

 present on the foliage. On June 22, the lower Ijranches of the 

 currant bush were baited, and then 100 male currant fruit flies 

 were liberated in a cage enclosing the bush. A week later, a few 

 ttypetids were found alive in the cage and at the end of two weeks 

 a single specimen was still alive. 



In 1914, the poisoned bait spray was tested in a commercial 

 currant and gooseberry garden consisting of 100 bushes. This 

 garden was not isolated, for currant and gooseberry bushes were 

 present not only in three adjacent dooryards but also in other 

 yards in the vicinity. To isolate this commercial garden as much 

 as possible, it was decided to spray all of the currant and goose- 

 berry bushes found in this locality. A total of 142 bushes con- 

 sisting of 18 currant and 124 gooseberry bushes were sprayed; 

 these were distributed in 8 different gardens. This entire area 

 had a natural isolation on three sides, — by the Stillwater and 

 Penobscot Rivers and by a bay of the Penobscot. 



Inquiry was made as to the infestation of the currants and 

 gooseberries during previous years. Some of the owners stated 

 that in some years practically all of the fruit had dropped to the 

 ground, but in other years the infestation was not so severe and 

 only about one-half of the crop was lost. The most reliable 

 data were obtained from the commercial grower, who kept a 

 record of the yield of the currant and gooseberry bushes during 

 the previous five years (Table 30). No attempt had been 

 made by any of the gardeners to control the fruit fly and all of 

 the infested drops had been allowed to remain on the ground in 

 prior years. 



In order to avoid any complication of results, it was decided 

 that none of the gardeners were to use their remedial measures 

 against the imported currant worm (Pteronus ribesii Scop.). 

 On May 26, we sprayed the foliage of the 142 currant and goose- 

 berry bushes by using 30 gallons of water mixed with 30 ounces 

 of arsenate of lead (paste). 



Throughout the season the same formula of the poisoned 

 bait was sprayed on the foliage of 100 bushes in the commercial 



