Paris-green experiment No. 1, April 19, 1889. 



May 4 tliis experiment was repeated with a fresher lot of beetles, with 

 more marked results, cnrculios commenciug to die two days after treat- 

 ment in all the poisoned lots but one, all of one lot being dead in nine 

 days, and in ten days all of every poisoned lot but a single beetle. lu 

 the check lot, meanwhile, only one had died. 



Parisgreen experiment Xo. 2, Mag 4, 1889. 



In both the above experiments, as also in the following, peach leaves 

 Avere used as food, and these were sprayed but once. 



All strengths of the poison mixture here killed the beetles feeding 

 on it, the difference being seen in the rapidity with which they took 

 ettect. In four days from poisoning tlie ratios killed were 42 per cent, 

 in lot two, 33 per cent, in lot tbree, 27 per cent, in lot four, and 18 per 

 cent, in lot five. 



Finally, May 17, a still more extensive experiment was begun with 

 Loudon purple, three hundred and forty-seven curculios being divided 

 into live lots as before, their treatment difiering from that of the fore- 

 going only in the substitution of London purple for Paris green. The 

 results were rendered, however, somewhat less satisfactory by the late- 

 ness of the season, which probably accounts for the number of deaths in 

 the check. Other parallel observations led to the conclusion that spent 



