16 BULLETIN NO. 4, DIVISION OF ENTOMOLOGY. 
Copperas.—This poison is recommended as a certain cure by Senator 
Emsen, and he shows his faith in it by using it himself and reeommend- 
ing it to all others; but all experiments so far tried have failed to de- 
monstrate its value as an insecticide—this insect of course in view. Dr. 
Brakeley has given it a thorough trial, and deems it valueless, and oth- 
ers give similar testimony. Decisive of ‘the matter is the testimony of 
Mr. Emsen’s secretary and manager. This gentleman informed me that 
he had transplanted some vines in a large jar, had placed therein a num- 
ber of larvie and so thoroughly soaked the whole with a solution of cop- 
peras that the leaves turned black; ina few days the larvie had devoured 
everything, and were still perfectly healthy and ravenous. 
Tobacco.—This is the favorite Cape Cod remedy, and the testimony 
gathered there is all in its favor. The tobacco is steeped in boiling 
water in the proportion of 15 pounds to a gallon, and sprinkled on the 
vines, a gallon to arod. The testimony of all who have so used it is 
to the effect that it kills the larvie wherever it reaches them, but they tind 
it somewhat difficult to reach them. There isa gentleman in Dennis, 
on the Cape, who makes somewhat of a business of preparing the decoe- 
tion, and he claims that it is infallible. I was unfortunate in reaching 
Dennis at camp-meeting time, and did vot succeed in finding this gen- 
tleman. Refuse tobacco of all sorts is used. 
Paris green.—This poison has been used in a few instances that I 
know of, and probably in a quiet way to a considerable extent on the 
Cape. In New Jersey its use has been confined to a few, but wherever 
it has been used it has been a decided success. I have seen bogs on 
which it was used, parts only having been treated with it, and the dif- 
ference in the appearance of the vines was striking: where it had been 
used the vines were green and flourishing, while elsewhere they were 
dry, unsightly, spun up and defoliated. It has been used stirred in 
water, a large tablespoonful to a pail of water, sprinkled on with a 
broom, and mixed with plaster, or rye flour. The latter is the prefer- 
able way. On Cape Cod the solution is preferred, in New Jersey the 
dry mixture is more favored. One grower mixed 3 pounds Paris green 
with 200 pounds cheap rye flour and scattered it broadcast while the dew 
was on the vines; it formed a slight paste and adhered everywhere ; 
soon after not a larva was found on the part so treated. The advantage 
of this poison over all others is that it does not lose by exposure to the 
air as do all those previously mentioned: its disadvantage is that, ap- 
plied when the berries have become fully formed, it sticks to them so 
closely that the gentleman referred to found the berries picked off the 
poisoned sections all more or less coated with the poisoned paste, which 
had dried on so closely that a heavy rain had not washed it off. Yet this 
poison may be safely applied early in the season to combat the first 
brood, before the berries have formed. 
Pyrethrum, or Persian Insect Powder.—With this I have made a num- 
ber of experiments: first as to its killing power. A few grains were 
