31 
BISULFIDE OF CARBON AS AN INSECTICIDE. 
Reprinted from Insect Life , l ot. 7, No. 2, page 108. U. S. Dept, oj 
Agriculture. 
At the late meeting of the Association of the Economic Ento- 
mologists, in August, 1894, at Brooklyn, N. Y., Prof. J. B. Smith, of 
New Jersey, read a paper on this subject. He referred to itslimited 
use for many years. He had become interested in Prof. Carman’s 
experiments in destroying aphides infesting melon vines, and be- 
gan experiments for himself. On pot-grown plants, he found that it 
killed the lice, but if used in large quantities, killed the plants also. 
The appearance of lice on cantaloupe and melon vines furnished him 
the opportunity he desired for experiment. He says : 
I procured a dozen wooden bowls thirteen inches in diameter 
and six inches deep, inside measurement, and a series of small, grad- 
uated tumblers, in which “1 teaspoonful’’ and “1 dram” corre- 
sponded. To get at the rate of evaporation I poured one dram into 
a graduate and left it exposed, but placed in a shaded spot. It re- 
quired fifteen minutes to disappear completely. Eleven badly in- 
fested hills were then covered’by bowls, the vines being crowded 
under when necessary, and 1 dram in a graduate was placed under 
each. At the end of twenty minutes 1 lifted one bowl, found that 
less than half the material had evaporated; that all the Coccinellidae 
were dead, the small lice dying, and the Diabrotica, ants, and large 
viviparous aphides were yet all alive. Ten minutes later there was 
little change. At the end of tliree-fourths of an hour, though scarce- 
ly more than half the liquid was gone, all save a few of the mature, . 
wingless, viviparous females were dead. In one hour there was yet 
liquid in all the graduates ; but all the aphides were dead, or ap- 
peared so. To test the matter, all the hills treated were marked to 
be examined later. Another series of infested hills was selected ; 
but the experiment was varied by using 2 drams of Bisulfide in 
.some cases, using a shallow saucer in others, pouring the liquid on 
the ground in two cases, and covering other hills with large, square 
boxes, some of them anything but tight. All coverings were left on 
for one hour undisturbed. Examined first a square box covering a 
shallow saucer with 2 drams of Bisulfide; found this all evaporated 
nnd every aphis killed. The bowls covering the saucers in which 1 
dram was used showed like results. Two square boxes which 
"'ere not tight, covering graduates with 2 drams of liquid, had all 
insects unaffected and the material scarcely half gone. The two 
bowls under which the Bisulfide was poured on the ground were 
then lifted and all the aphides were found dead. All the other hills 
covered by bow-ls showed all the lice dead and not all the Bisulfide 
evaporated. The hills first treated were again examined and there 
