68 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 
during the latter part of June; or, still better, by collecting a hun- 
dred or so full-grown larve about the last of May and placing them 
in a shallow box, the bottom of which consists of a pane of glass, the 
box containing about 8 inches of moist soil. Some of the larve will 
go through the soil to the glass surface, where their transformations 
may be watched and the time of emergence definitely determined. 
In making the spray applications care should be taken to cover all 
parts of the foliage. For thorough work, 100 gallons of liquid spray 
per acre is necessary and a pressure of not less than 100 pounds should 
be maintained. Two such thorough applications—one as the beetles 
emerge, and another not more than a week later—judging from the 
results obtained in our work of the past season, will prove sufficient 
to reduce the infestation of this insect to a point where it will not 
seriously affect the vitality of the vines. 
The formula used in our experiments during the past season is the 
Bordeaux mixture formula, recommended by the Bureau of Plant 
Industry for combating the black rot of the grape, to which was 
added 3 pounds of arsenate of lead, the latter ingredient being the 
insecticide. 
Spray formula recommended. 
Copper sulphate (bluestone or blue vitriol) _-_________ pounds__ 5 
Nresh stone tne soo see eras EE AES eth Maliad: at hg TJ GO 282 Yay 
Arsenate Of dipadla 2 Sees, eee ee wp De dQ2t 22 8s 
WALD 262 255s ee ge gallons__ 50 
