7 
ARSENICAL POISONS FOR THE CODLING MOTH. 
(Carpocapsa pomonella, L.) 
Order Lepidoptera. Family Tortricidje, 
I published last year (1885), in the Report of the State Department 
• Agriculture* and in the Transactions of the State Horticultural 
3ciety,t a report on some preliminary experiments made with 
-A) arsenical poisons and with lime, for the codling moth and the 
irculios, the general result of these experiments going to show 
at about two thirds of the apples subject to loss through the 
•dling moth, and one half of those liable to be destroyed °by the 
irculios, might be saved by spraying eight times with Paris 
een. Last year was, however, an exceptional year, the apple 
op being very unusually light, following a good crop of the year 
‘fore. Moreover, eight times’ spraying was clearly an excessive use 
the poison, the arsenical compounds being presumably ineffective 
;ainst the second brood of the codling moth, and certainly dan- 
‘ious to health, if not to life, if used on the apple after mid- 
mmer. Our work of last season was consequently inconclusive 
th lespect to some important points; and I made this summer 
886) similar experiments on a larger scale, intended to com- 
ete. and test the evidence of the year before, to try arsenic in 
lution in comparison with London purple and Paris green, and 
pecially to test carefully and thoroughly the effect of a moderate 
miber of sprayings with poisonous insecticides applied only so 
rly in the season that there could be no possible question of 
nger to the consumer of the fruit. I used this year Paris green 
d a solution of arsenic in comparison on eight selected trees, 
vo of these were sprayed with a solution of white arsenic and 
: with Paris green in water—two of the six sprayed once, May 
; two twice, May 11 and 24; and two three times—the last, June 
Companion trees were selected as checks upon each of those 
ns treated, the check trees being, of course, left unpoisoned. 
The Paris green mixture was the same as last year, three 
irths of an ounce by weight, of a strength to contain 15.4 per 
.it. of metallic arsenic, being simply stirred up in two and a 
*Appendix, pp. 26—45. 
+Vo). xix, pp. 103— 124. 
