THE COLORADO POTATO BEETLE. 1 79 



(H). 2 lbs. Paris green ; 3 lbs. lime. No cleaner than G. 



(I). 3 lbs. Paris green; 3 lbs. lime. Quite free from bugs. 

 Only a few on occasional plants. 



(K). x / 2 lb. Paris green; Bordeaux mixture. Very few bugs. 



(L,). 1 lb. Paris green. Bordeaux mixture. Much the same 

 as K. 



(M). 2 lbs. Paris green; Bordeaux mixture. Not quite as 

 clean as L and K. 



(N). 3 lbs. Paris green; Bordeaux mixture. Not as clean 

 as M, L, or K. 



(E). (This plot lies next to F in the field), i lb. arsenate 

 of lead; 3 lbs. lime. Quite clean. 



(D). 2 lbs. arsenate of lead; 3 lbs. lime. Rather better than 

 E. 



(C). 3 lbs. arsenate of lead; 3 lbs. lime. Not as clean as D 

 or E. 



(B). 1 lb. arsenate of lead; Bordeaux mixture. Better than 

 C. About the same as E. 



(A). 2 lbs. arsenate of lead; Bordeaux mixture. Very 

 clean ; about the same as D. 



(O). (In the field, this plot lies next to N). 3 lbs. arsenate 

 of lead ; Bordeaux mixture. Very clean ; much cleaner than K, 

 L, M or N. 



From the above it is seen that Paris green with Bordeaux mix- 

 ture was more effective than Paris green without the Bordeaux. 

 It was expected that the result would be otherwise, as in other 

 cases the bugs seemed to dislike and avoid the copper salts as far 

 as possible. It is probable that Wednesday's shower washed off 

 the Paris green when applied with white wash (lime) but did not 

 affect it as much when it was applied with Bordeaux mixture. 



The arsenate of lead seemed to kill equally as well whether 

 applied with lime or with the Bordeaux mixture. This can 

 probably be explained by the fact that arsenate of lead when once 

 dried is with difficulty washed from the foliage. The arsenate 

 of lead killed better than did the Paris green. This may be 

 explained by the washing off by the shower of the Paris green 

 both with and without Bordeaux mixture. 



One-half pound of Paris green or 1 pound of arsenate of lead 

 applied with the Bordeaux mixture was effective in cleaning the 



