81 
ently not inconvenienced by the dust that adhered to them. Flea 
beetles not killed, but evidently demoralized and deserting rapidly, 
Its effects on Aphididw were quite satisfactory. All species to which 
it had been applied seemed to be killed or paralyzed and had with- 
drawn their beaks from the stems or leaves, and if they had not already 
fallen did so upon the slightest jar. At the same time Chrysopa and 
Coccinellid larve appeared but little, if any, injured, and were seen 
making their way to other hunting grounds on which the game should 
not be so pungently spiced. Syrphus-fly larve, however, did not 
escape, and all that received much of the dust were killed. 
At 7 in the evening more of the powder was distributed on infested 
potatoes and on all species of Aphis that could be reached. 
June 3.—The effects of the Dust on the Colorado potato-beetle are by 
no means so immediate and thorough as claimed in the circulars of the 
manufacturers. Repeated applications would seem to be necessary to kil] 
the larvze, while according to my experience the perfect beetle will live 
for days thoroughly dusted with the powder and inclosed in a box. At 
the same time it certainly does protect the plants to which it is applied, 
especially while fresh, by acting as a repellant. 
September 10.—Tested the Dust on larvee of the cabbage butterfly 
which are beginning to be found again in cabbage fields. Used the 
insecticide in the open air, also on a few full-grown larve placed-in 
jar, under muslin cover. 
September i5.—Plants dusted seem almost entirely free from worms, 
but several of the larvie confined completed their first transformation 
without apparently receiving any injury from the powder. 
September 21.—Repeated these tests with powder taken from the bot- 
tom of the can and found that young Pieris larvee succumbed to its 
effects in two or three hours, while the larger larvie often lived more 
than twenty-four hours, not eating, however, in the mean time, but 
lingering in a lethargic state until dead. 
October 19.—Renewed these experiments on the latest brood of worms 
which are now to be found of all sizes on cabbages, turnips, and nastur- 
tiums. The immediate effect of the powder is to cause the larvee to 
cease feeding and toss themselves about uneasily, making efforts to 
free themselves from the irritating substance. Two hours later all were 
in a lethargic state, many lying upon their sides in the folds of the leaves 
and on the ground. They would squirm when touched, but gave no 
other sign of life. Twenty-four hours later all the small larve were 
dead ; the others that had passed the second molt still lived, but were 
inactive with a sickly color. Forty-eight hours afterward all were 
dead. From these tests and experiments I conclude that this X. O. 
Dust may be classed with reliable remedies for this and probably other 
Lepidopterous cabbage pests, its value being.nearly equal to that of 
Pyrethrum powder. 
This remedy was also used on Tarnished Plant-bug with the effect of 
23479—No, 22——6 
