GRAPE ROOT-WORM TN VESTKIATTOXS TX 1<»07. 67 



eggs or ovei': mcd'tiim. when containing about 30 eggs: and sukiIK 

 Avhen containing about 10 eggs. Examinations wore made in three 

 l^arts of tlie vine^'ard. An unsprayed check phit of 1 acre was left 

 on one side of (he \ ineyard and the (^g,^ chisters found on 25 con- 

 secutive vines, at a (hite after the maximum number of eggs had been 

 deposited, were recorded in the manner just describech A simihir ex- 

 amination was made on 25 consecuti\-e vines in the sprayed portion, 

 six rows over from the check phit. and a fui'ther examination on 25 

 s})rayed vines on the opposite side of the vineyard, the main object 

 of this last examination being to determine the uniformity of egg 

 dejiosition throughout tlu^ vineyard. 



RECOMMENDATIONS BASED ON OBSERVATIONS AND RESULTS OF 



SEASON'S WORK. 



The woik of the past season, at Xortli K;»st. Pa.. indi<'ates that 

 tliorough and timely spraying of infested vines with arsenate of lead 

 will, by preventing the deposition of a sufficiently high percentage of 

 eggs, reduc(> the number of grape root-worms to such an extent that 

 they will not seriously aifect the growth of the vines. In order to 

 make the spray effective, however, the first application nnist be made 

 either immediately before, or as soon as the first beetle is seen in 

 the vineyard. 



Since the emergence of the beetles fioui the soil is governed largely 

 by weathei- conditions, especially those of temperature, no definite 

 date for making the first application can be given. For instance, the 

 records of Feb and Slingerland show that in normal seasons the 

 beetles connnence to apijeai- during the last week or ten days in June, 

 whereas, in 1007. none was found in vineyards by the writer until 

 July 15, although he had spent a huge poi'tion of every day in the 

 vinej'ards for a week or two preceding that date. • Hence, it is very 

 necessary to watch the develojjment of the larva^ and pupa> in the soil. 



The emergence of the beetles in our breeding cages during the past 

 season coincides very closely with the appearance of the beetles in 

 vineyards. The first two beetles appeared in the cages on the morn- 

 ing of July 14; by the 15th a large number had emerged, and the same 

 day the beetles were very numerous on foliage in vine^'ards on gravel 

 soil. Nearly 50 per cent of the beetles which matured from 750 larva>, 

 placed in the soil in our breeding cages, emerged (m the third and 

 fourth days after the first beetle appeared. This simultaneous emer- 

 gence of so large a percentage of beetles shows the necessity of having 

 the first spray application upon the vines by the time the fii'st beetles 

 appear, or. at least, to have the s])raying equipment in readiness so 

 that the application may be made with the least possible delay. 



The time of emergence of the beetles can be determined quite closely 

 by examining the condition of the pupa' in the soil every few days 



