ICO STATE roMOLOGlCAL SOCIETY. 



almost surely fatal to any tender sort. Fall and winter pruning is 

 alsv> injurious to tender sorts, as the bark around the wound will be 

 killed lor some distance, and there is little hope that it will ever 

 afterwards heal. But any of the varieties that never become black- 

 hearted may he pruned ''whenever your knife is shar[)." remember- 

 ing this, that .]une pruning is a shock more or less severe, according 

 to the amount of wood removed. "Prune in summer for fruit" i^ an 

 old and correct rule, for the very reason that the shock of summer 

 pruning (like anything that weakens the tree) tends to cause the 

 formation of fruit buds. The effect is much like that of root prun- 

 ing, and both must be practised with moderation and judgment. 



ARSENICAL POISOXS FOR THK CODLING MOTH. 



[From Bulletin No. 1, of the Entoinologigt of the State of Illinois, Prof. S. A. Forbes, 



Ph. D., 1887.] 



The Paris green mixture was of the same strength as last vear, 

 — three-fourths of an ounce by weight, of a strength to contain 15.4 

 per cent of n)etallic arsenic, being simply stirred up in two and a half 

 gallons of water. The arsenic solution was made by boiling one 

 ounce of arsenic in one quart of water, and adding this solution to 

 twenty gallons of cold water. The method of procedure was pre- 

 cisely as last year, the trees being thoroughly sprayed with a hand 

 force-pump, and with the Deflector Spray and Solid Jet-Hose Nozzle, 

 manufactured by the Lowell Paucet Company, Lowell, Mass. The 

 fluids were thrown in a fine mist-like spray, applied until the leaves 

 began to drip. 



As a summary statement of the final issues of the Paris green ex- 

 periments for the years 1885 and 188G, we may say in a word, that, 

 in 18'S5, eighty-seven per cent of the fruit exposed to damage by the 

 codling moth was preserved to ripening by the poisons applied, and 

 that fifty-eight per cent of the picked fiuit had been thus preserved ; 

 or, that taking picked and fallen fruit together, sixty-nine per cent, 

 which would otherwise have been sacrificed, had been saved by our 

 remedial measure. 



Purthermore, during 1886, seventy-three per cent was saved from 

 falling by a single spraying, seventy-seven per cent by two, and 

 about seventN'-two per cent by three. The difference unfavorable to 

 the last was doubtless due to the accidental differences in trees and 

 treatment. 



