FEEDING EXPERIMENTS WITH POISONS. 185 
London purple and water in the proportion of 1 pound to 120 gallons is much too 
strong a mixture for plum trees. One-half of this strength is as strong a mixture as 
should be used. 
In summing up the situation as to the use of arsenicals against the 
curculio, in 1887, Riley and Howard state: 
On the whole, the remedy is one which is a desirable addition to our list, although 
it will never become so great a success as the application of the poisons for the codling 
moth, and for two reasons: (1) The egg is deposited and the beetle gnaws preferably 
upon the smooth cheek of the fruit where the poison does not readily adhere and from 
which it is more easily washed off; (2) the larva eating directly from the flap does not 
come in contact with the poison as does the larva of the codling moth. 
The foregoing will give a fair idea of the rise of spraying with arsen- 
icals for the curculio. By about 1890 the practice unquestionably 
had become rather general, although jarring was still employed by 
many growers. The injury to the foliage of stone fruits by such 
arsenicals as Paris green and London purple, frequently noted by 
orchardists and the early experimenters, no doubt greatly retarded 
the adoption of these poisons. The development, however, in 1892, 
by the Massachusetts Gipsy Moth Commission, of arsenate of lead, an 
insecticide much less caustic to the foliage than either Paris green or 
London purple, gave a considerable impetus to spraying for the cur- 
culio, especially on peaches and plums. Spraying, however, had been 
in effect two decades or more before its real merits on a commercial 
basis had been determined. The careful experiments of Forbes, 
Weed, Alwood, and perhaps others, had shown unmistakably that the 
injuries could be materially reduced by frequent spraying, and the 
testimony of many fruit growers was decidedly in favor of it. There 
were others, however, who doubted its efficiency, and continued the 
practice of jarring. 
FEEDING EXPERIMENTS WITH POISONS. 
The point has several times been raised in the case of arsenate of 
lead whether this did not act mainly as a repellent; and in an exper- 
iment by W. W. Chase a report bearing on this question is given." 
A single small peach tree was covered with fine wire screen. The 
tree was literally soaked with lead arsenate, 3 pounds to 50 gallons 
of water, and after the poison had dried another application was 
given. The day following, May 11, 372 curculios which had been con- 
fined 48 hours without food were liberated in the cage. Subsequent 
close observation failed to discover a single beetle feeding on the tree, 
and in fact the beetles seemed to have the strongest aversion to it. 
At the end of 10 days all the beetles were dead, except a few which 
may have escaped. It would appear to the writers that in this case 
1 Bul. 32, Georgia State Board Entomology, p. 27. 
