22 BULLETIX 352, U. S. DEPAETMEXT OF AGRICULTURE. 



sulphate (40 per cent) on June 27. Of the beetles that fell from the 

 tree, 318 were collected on a sheet and placed in a ventilated cage in 

 the insectary. Five days later practically aU of them, over 98 per 

 cent, stiU showed no signs of life. 



Weaker dilutions of 40 per cent nicotine sulphate were tested on 

 September 9 on beetles of the new brood. Pin-cherry trees were 

 sprayed, because at this time the beetles were feeding on no other. 

 The following strengths were used: One part of nicotine sulphate to 

 800, 1,000, and 1,200 parts of water, respectively. Soap was added 

 as in the first experiment at the rate of 2 pounds to 50 gallons of 

 liquid. None of these strengths was effective, and none of them 

 showed the immediate effects that followed spraymg with a solution 

 at the strength of 1 to 600. Man}' of the beetles hit with the sprays 

 of the strengths of 1 to 800 and 1 to 1 ,000 became very sluggish and 

 in 10 or 15 minutes appeared dead. Very few of those hit by the 1 

 to 1,200 solution appeared injured at aU. About 150 beetles were 

 collected from trees sprayed with each solution and placed in jars in 

 the insectary. On the evening of September 10, 60 per cent of the 

 beetles sprayed with the 1 to 800 solution, 68 per cent of those sprayed 

 with the 1 to 1,000 solution, and 96 per cent of those sprayed with the 

 1 to 1,200 solution were active and feeding. 



Results from Spraying by Growers. 



Immediately following the advent of the cherry leaf-beetle in the 

 Lake Erie grape belt there was unusual spraying activity to check it. 

 Arsenate of lead was used in most instances, but applications of lime- 

 sulphur, Bordeaux mixture, nicotine sulphate, soap, and lime, used 

 in various combinations and at various strengths, were also made. 

 The results were various. 



Orchards in which arsenate of lead had been used at the rate of 5 

 pounds to 50 gallons of water, with and without lime, were observed 

 by the "\^Titers. In these orchards the trees were generally quite well 

 protected, although few dead beetles were found on the ground under 

 the trees. Where weaker solutions of poison were used the results 

 were far from satisfactory in the orchards observed. The use of 

 sweetened arsenate of lead was observed in only one orchard outside 

 of the experimental plats, and in this instance it was entirely unsuc- 

 cessful. The spray was applied inmaediately before a heavy rain, 

 which washed it all off. 



A number of combination sprays in wliich 40 per cent nicotine 

 sulphate was used were successful. The nicotine sulphate was 

 sometimes used at rates as strong as 1 to 400. The following is a 

 typical effective mixture: Arsenate of lead, 3 pounds; 40 per cent 

 nicotine sulphate, 1 pound; laundry soap, 2 bars; water, 50 gallons. 



