10 



lime in the proportion of 1-1- lb. of each to 150 gal. of water, and 

 sleeved in ten caterpillars. One died on the 6th ; four on the 8th ; 

 two on the 9th ; one on the 10th ; one on the 14th : and the last on the 

 18th. Leaves not injured. 



June 0. Sprayed a branch of an apple tree with Paris green and 

 lime in the proportion of 1 lb. of each to 150 gal. of water, and 

 sleeved in ten caterpillars. One died on the 7th ; one on the 8th ; 

 one on the 10th ; one on the 12l,h ; one on the 17th ; one on the 18th ; 

 and the rest on the 19th. Foliage not injured. 



CONCLUSIONS. 



A comparison of these experiments with those made on the tent 

 caterpillar with Paris green alone, in 1891, and published in bulletin 

 No. 19 of this Station, seems to indicate that Paris green and lime 

 together act more slowly than Paris green alone. It is undoubtedly 

 true that the lime unites with the soluble arsenic, forming a com- 

 pound which is insoluble in water, and this is why it is less injurious 

 to the foliage, but does it not render it less poisonous to insects? I 

 do )iot wish to express a positive opinion in this matter without 

 further investigation. 



JAMESTOWN WEP]D {Datura stramonium) AS AN 

 INSECTICIDE. 



This plant has been recommended as an insecticide, and my atten- 

 tion was especially called to it last summer by Mr. A. I. Hayward 

 who stated that he had apparent success in destroying cut worms 

 with it. He informed me that he steeped it in water and sprinkled 

 it around the plants. 



One ounce of the dried leaves obtained from the druggist was 

 steeped in a pint of water for four hours and this liquid was sprayed 

 on potato leaves on which larvae of tlie Colorado potato beetle were 

 feeding, but it did not affect them. It was also tried on rose beetles 



