February, '16] Goodwin : grape berry worm 97 



Control measures were at first devised with the idea of reducing 

 the size of the early broods of worms, there being supposedly three 

 broods, thus preventing the serious attack of the last brood in the 

 season. The large quantities of poison used was dangerous and much 

 doubt was expressed concerning the possible deleterious effects of 

 spray still adhering at picking time. The life-history of the berry 

 worm was incomplete, leaving the experimenter without definite ideas 

 of the exact time to spray and with what to spray in order to control 

 it. The striking result obtained by Professor Gossard at Kelley's in 

 1907 indicated that the date of spraying should be pushed as late as 

 was consistent with safety, but its hmit was undetermined. Life- 

 history studies have shown, however, that in the 1907 experiments 

 the third spraying of the season was made before the first brood larvae 

 were half grown and many larvse had not been hatched for more than 

 a week. The poisonous effect of this spraying would be of little value 

 by the 3d to 10th of August as experiments of later years have shown. 



In 1909 a small vineyard at Wooster at the Ohio Agricultural 

 Experiment Station was sprayed with dilute lime-sulfur 1 gallon in 

 50, with 3 pounds of arsenate of lead, and compared with arsenate of 

 lead 3 pounds, Bordeaux 3-6-50, and 1 pound of soap. The Hme 

 sulfur practically defoliated the section treated and also destroyed 

 the set of grapes. These were the only important results of 1909. 



The grape berry worm control work was discontinued for several 

 years on account of the difficulty in getting satisfactory cooperators, 

 and also the partial disappearance of the berry worm. 



In the fall of 1912 grape growers in the East Cleveland district ap- 

 pealed to the Ohio Agricultural Experiment Station for help, as the 

 berry worm had almost destroyed their crop. A similar appeal came 

 from the west of Cleveland District in 1913. 



In 1913 experimental work for the control of the grape berry worm 

 was begun in the vineyard of Dr. C. C. Arms at Euchd, O. The 

 spring was cold and the grapes were slow in starting. Experimental 

 work was based on previous experience and on the work of Johnson 

 and Hammar at North East, Pa., given in Bulletin 116, Part II, 

 Bureau of Entomologj^, U. S. D. A., and a program planned accord- 

 ingly. Life-history studies had been started the fall previous as con- 

 trol measures depended largelj^ on knowing the habits of P. viteana in 

 northern Ohio. 



The set of bunches before bloom was light, promising only a small 

 crop of grapes for 1913. Plots were selected and a spraying made 

 before the grapes bloomed. The plots selected were located on almost 

 level land and each plot consisted of about two-thirds of an acre of 

 grapes. The larger part of this section was Concords, but the plots 



