90 THE GKAPE EOOT-WOKM. 



than they do several days later, during the period of egg deposition, 

 and since the object of this application is to prevent egg deposition, 

 it is very desirable that the poison application be made early, so 

 that the first meal of the beetle will consist of poisoned foliage. 



The beetles may be expected to appear on the foliage during the 

 last week or ten days in June or the first few days in July, depending 

 on the earliness of the season. After June 20 vineyardists should 

 keep a sharp watch for their appearance and have their spray equip- 

 ment in readiness to make the first spray application. 



The development of the pupa in the soil will also indicate approxi- 

 mately the appearance of the beetles, for they may be expected to 

 appear within a week or ten days after the pupse can be found in the 

 soil in considerable numbers. Since a large majority of the beetles 

 emerge from the soil from ten to fifteen days after the appearance 

 of the first beetles, it is necessary to make a second spray applica- 

 tion within a week or ten days after the appearance of the first 

 beetles. In this way it will be possible to keep the foliage well 

 covered with poison spra.y during the emergence of a maximum 

 number of the beetles. 



Observations and experiments indicate that, if these two appli- 

 cations are made promptly and thoroughly, this pest can be reduced 

 to such small numbers that it will not materially affect the vigor of 

 the vines. 



The spray formula recommended is as follows : 



Arsenate of lead pounds. . 3 



Water gallons. . 50 



Copper sulphate (blue vitriol) pounds. . 5 



Lime (fresh lump lime) do 5 



The first ingredient of the formula, arsenate of lead, is the arsenical 

 poison and the active killing agent or insecticide. The two last 

 ingredients, copper sulphate and lime, with the water, form Bordeaux 

 mixture, which is a fungicide used to control black rot, mildew, and 

 other fungous diseases of the grape. Fortunately this insecticide 

 and this fungicide can be mixed without changing the quality of 

 either, and for this reason their use in combination is recommended. 



DESTRUCTION OF THE PUP^. 



In the vineyards throughout the Lake Erie grape belt pupation of 

 the grape root-worm may be expected to commence about June 10, 

 reaching the maximum about June 15 to 18. These dates can not 

 be fixed, however, on account of variation in weather conditions. 

 The exact time of pupation of the insect can best b& determined by 

 the person operating the infested vineyard by carefully removing the 

 soil around the base of infested vines to a depth of from 2 to 4 inches. 



