188 
osed similarly to the open air. As this powder had been left 
n for three or four days, it had doubtless greatly diminished in 
iiency, and its action was less prompt than the smaller propor- 
t suspended in water. In an hour many were still alive, but 
I e were at all active. In four hours nine of the specimens could 
k when placed upon their legs, and the remaining twenty-nine 
ij Id all move their legs, but were otherwise helpless. In twenty- 
; r hours all were dead but two, which could move their legs very 
I vly and feebly, and by the morning following all were dead. 
Tom the above experiments it is clear that in pyretlirum we have 
: extraordinarily effective insecticide for this species, and that it 
i be safely applied either in powder diluted with flour, or sus- 
ded in water,—in the latter case being sprayed or sprinkled upon 
plants. 
he Kerosene Emulsion .—While this substance would be equally 
dicable either to the strawberry field, the vegetable garden, or 
orchard, it was found worth while, also, to experiment with a 
lewhat cheaper insecticide, viz., the kerosene emulsion. This 
ild, perhaps, be inapplicable to the strawberry field, except early 
die season, as the kerosene would be apt to injure the flavor of 
fruit; but in the garden and orchard it might be applied as 
lily as pyretlirum. 
'or the first experiment, an emulsion of equal parts of kerosene 
I milk was mixed w r ith twenty parts of water, the dilution emi¬ 
nently containing only two and one-half per cent, of kerosene, 
pray of this was thoroughly applied to thirty-five adult plant 
;s collected under leaves on the ‘22d of November, and in two 
rs nearly all seemed dead, but in two hours more three were 
imencing to revive. After another two hours, these three were 
ning about, and two more were slowly reviving. In twelve hours 
r of the specimens had fully revived, one showed some signs of 
], and the remainder were all motionless and apparently dead. 
ks the specimens used in the preceding experiment were enclosed 
a large bottle after being treated with the emulsion, a second 
:i ilar experiment was tried upon forty-two individuals exposed to 
open air. These were stupid with cold w T hen brought in from 
field* but all revived in a warm room, and became extremely 
; ive. A fine spray of the dilution was applied until all were 
j roughly wetted. These w r ere then placed on blotting paper in the 
tom of a breeding cage. In three hours, fifteen were seemingly 
id, not moving at all when touched, but the remainder of them 
e variously active, some of them crawling about. In another 
i:ir and a half only four were dead, seven of the others being 
3rd, and all the others scattered about the breeding cage, ap- 
ently unharmed. In twenty hours six of the bugs were dead, 
| 3e showed some signs of injury, but the remainder seemed en- 
ly unharmed. 
kn experiment was next tried upon twenty-five specimens with a 
i, lure of kerosene emulsion of twice the strength of that given 
ve, containing, consequently, five per cent, of kerosene. These 
e placed under a large bell jar, so that they were exposed to the 
i 
I 
