370 State Horticultural Society. 



ARSENATE OF LEAD FOR THE CURCULIO. 



Codlin moths and curculio are such universal pests in the 'Or- 

 chard, reducing the quantity and quality of the fruit from 20 to 80 

 per cent, every season, that we are tempted to quote liberally from 

 a bulletin on the subject, just issued by the Agricultural Experi- 

 ment Station of Illinois, S. A. Forbes, Entomologist. This bulletin, 

 entitled "Spraying Apples for the Plum Curculio," deals also with 

 a remedy for the codlin moth worm, and is very complete in detail- 

 ing experiments with the curculio. 



The remedy used in the experiments is arsenate of lead, pre- 

 pared by dissolving 12 1/2 ounces of the acetate of lead and 5 ounces 

 of arsenate of soda, and pouring them into a barrel containing 50 

 gallons of water. The varieties of apples in the experiments were 

 Ben Davis, Wine Sap and Benoni, and from 4 to 8 sprayings were 

 given, with the following results : 



Four times spraying of Ben Davis apples with arsenate of lead 

 at intervals of ten days, beginning May 6, increased bulk of crop 

 by 54 per cent., number of apples by 26 per cent., and average size 

 of fruit by 21 per cent. Diminished curculio injuries to the apple 

 by 69 per cent., which is the measure of the protection due to treat- 

 ment. 



Six times spraying of Benoni apples with arsenate of lead, be- 

 ginning May 6, increased bulk of crop by 40 per cent., and number 

 of apples by 47 per cent. 



Six times spraying of Ben Davis apples, beginning May 6, in- 

 creased bulk of crop by 34 per cent., number of apples by 11 per 

 cent.', and size of fruit by 24 per cent. Sixty-eight per cent, of ap- 

 ples which would have been injured were protected from curculio 

 by the treatment. Total value of crop increased, 150 per cent. 



Cost of each treatment, including materials, labor, subsistence 

 and use of team, was 4 to 5 cents per tree, or 17 cents for four 

 treatments found most effective. 



Analysis of peelings from apples sprayed the preceding day 

 with four times the usual strength of arsenate of lead, showed .256 

 of a grain of arsenate to a pound of the peelings, or approximately 

 four pounds of the peelings to a grain of arsenic. 



In his summary of results Prof. Forbes says that four spray- 

 ings of apple trees of late varieties, exposed to very heavy attack of 

 the plum-curculio, the first spraying applied in early May just as 



