THE CHERRY LEAF-BEETLE. 21 



effective in the first experiment. No lime was added to the un- 

 sweetened mixture and the molasses was used at the same rate as 

 formerly, viz, IJ gallons to 50 gallons of water. 



Dead beetles were found under all the trees sprayed, but they were 

 far more numerous under the trees sprayed with the sweetened mix- 

 ture than under those sprayed with the unsweetened mixture. Also 

 there was less feeding on the trees sprayed with the sweetened 

 arsenate, although there was comparatively little on either, while 

 the unsprayed check was loaded with beetles. 



EFFECT Oy LIME IN COMBINATION WITH ARSENATE OF LEAD. 



To test the effect of lime as a repellent when used in sprays in com- 

 bination with arsenate of lead, beetles were caged on parts of a tree 

 in the insectary yard sprayed with lime water at the rate of 1 pound 

 to 50 gallons and 5 pounds to 50 gallons. In both cages the beetles 

 fed as freely on the leaves thus sprayed as on those that had not been 

 sprayed. 



Contact Sprays. 



soap-carbolic acid solution. 



A solution of fish-oil soap, 10 pounds to 50 gallons of water, to 

 which three-fourths of a pint of carbolic acid was added, was tried 

 as a contact spray on June 11. Immediately upon the application 

 of this solution the majority of the beetles fell from the tree, appar- 

 ently dead. Several hundred of these were gathered from the ground, 

 placed in vials, and taken to the insectary. By the evening of the 

 next day practically aU of the beetles were active again and appar- 

 ently uninjured by the spray. The solution is not permanently 

 repellent, for the trees thus sprayed were badly attacked again tvt^o 

 days after the application of the spray. This spray was not injurious 

 to foliage. 



NICOTINE SULPHATE. 



A solution of 40 per cent nicotine sulphate at the rate of 1 part to 

 600 parts of water, to which was added fish-oil soap at the rate 

 of 2 pounds to 50 gallons of liquid, was used as a contact spray on 

 June 11. The effect was apparently similar to that of the soap-car- 

 bolic acid solution; some of the beetles escaped by flight but the 

 majority fell from the tree when hit by the spray and soon appeared 

 dead. Several hundred of them were gathered and taken to the 

 insectary to test the permanence of this state. They were kept 

 mider observation for five days without showing any signs of life. 



In order to compare the effectiveness of nicotine sulphate without 

 soap, a large tree in the insectary yard was sprayed with nicotine 



