25 



began, caught no less than 24,000 weevils, but most of them, though 

 apparently dead, showed signs of life when disturbed. Some were in- 

 closed in a bottle for observation, but less than 8 per cent, recovered. 

 Two days later two more trees were sprayed with what remained of the 

 solution, under the same conditions except that in this case there was 

 no rain. The canvas under one of the trees was blackened with the 

 adults which fell. These, however, were more lively than those in the 

 former trial, and most of them gradually recovered. Only one fifth of 

 the original number remained on the canvas two days later, and many 

 of these were alive. It was concluded that this soap was worthless as an 

 insecticide against the apple flea-weevil, and no further experiments with 

 it were made. Possibly the heavy rain had something to do with the 

 high mortality in the first instance. 



Nicotine sulphate liquid. — A number of low-hanging branches were 

 sprayed with the "black leaf forty" brand of nicotine sulphate, prepared 

 as follows : 



Black leaf forty ^ ounce 



Laundry soap; 2 ounces 



Water ; 3 gallons 



A canvas was spread under the tree to catch the weevils as they 

 dropped. Some of them showed signs of life and were sprayed again 

 while lying on the canvas. Three hours later all were dead. 



Kerosene emulsion. — Branches infested with the weevil were sprayed 

 in the same manner with kerosene emulsion at strengths of 5 per cent., 

 7J/2 per cent., 10 per cent., and 15 per cent. The 5 per cent, emulsion did 

 not kill the beetles outright, and it was necessary to spray them as they 

 lay on the canvas to insure their death ; but the stronger emulsions ap- 

 parently killed all the adults hit by them. 



To test further the eflfectiveness of kerosene emulsion, 30 trees 

 were sprayed with a 5 per cent, and 20 trees with a 7^ per cent, emulsion. 

 Two canvases, each 15X30 feet, were spread under the trees while the 

 spraying was in progress, each with a 1X4 inch board along one end 

 as a convenience in moving it from tree to tree (see Figure 15). A 

 man or a boy was needed to handle each of the canvases. As soon as 

 the spraying of a tree was finished the canvas-men dragged the canvas 

 quickly to the next tree, and little delay was occasioned. 



The weevils fell on the canvas in large numbers, and here they were 

 sprayed again, practically all of them being thus killed. After the ninth 

 tree was sprayed counts were made of the dead weevils in two areas 

 of a square foot each, 250 weevils being found on one square foot and 

 300 on the other. It was estimated that there were not less than 80,000 

 weevils on the canvases, indicating an average .of nearly 9000 per tree 

 which were killed by the treatment. 



After the spraying was completed, counts were made to determine 

 the comparative numbers of weevils on sprayed and unsprayed trees 



