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ently not inconvenieuced by the dust that adhered to thern. Flea 

 beetles not killed, but evidently demoralized aud 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 aud 

 Coccinellid larvae appeared but little, if any, injured, and were seen 

 making their way to other hunting grounds on which the game should 

 not be so pungeutly spiced. Syrphus-fly larvae, 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 aud thorough as claimed in the circulars of the 

 manufacturers. Repeated applications would seem to be necessary to kill 

 the larvae, 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 larvae 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 larvae placed in 

 iar, under muslin cover. 



September 15. — Plants dusted seem almost entirely free from worms, 

 but several of the lar va3 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 larvae succumbed to its 

 effects in two or three hours, while the larger larvae 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 

 w r hich are now to be found of all sizes on cabbages, turnips, and nastur- 

 tiums. The immediate effect of the powder is to cause the larvae 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 larvae 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 

 Pyre thrum powder. 



This remedy was also used on Tarnished Plant-bug with the effect of 

 23479— No. 22 6 



