55 



lodged, and u to make assurance doubly sure," it is stamped into the 

 earth. On most of the insect foes of the plant lice the dust produced 

 no disastrous effect, but the larvae of Syrphid.se would, in some cases, not 

 recover from the pungent coating. 



Arsenites of ammonia, — This new preparation, for which P. J. Andres, 

 25 Pearl street, New York, is the agent, was sent to me for experiment, 

 in accordance with directions from the entomologist of the Department 

 of Agriculture. It did not reach me until about the 1st of June, too 

 late for use on a number of insects. It is a clear solution of arsenic in 

 aqua ammonia, and apparently does not differ much from a preparation 

 of my own devising, as reported on two years ago, and with the effects 

 of which on vegetation I was not entirely satisfied. The directions ac- 

 companying each of the gallon bottles, in which it is put up, are to use 

 one tablespoonful of the liquid to a gallon of water. 



Junel. — Weather clear and hot. Prepared a quantity of the fluid as di- 

 rected and had it applied to the following plants : To potatoes, on which 

 were a few Doryphora larvae ; to rose bushes, on which still lingered a 

 few larvae of Selandria rosce, Characlea angulata, and Amphipyra pyrami- 

 doides; to cabbage, covered with full-grown and young larvae of Pieris 

 rapoz; to cucumbers and squash infested with Diabrotica. It was too 

 late in the season to test it thoroughly on apple for the Codling Moth, 

 and as there were scarcely any peaches or plums or curculios. its effect 

 on the latter insect can not be reported upon. Portions of the trees as 

 well as of cherry were sprayed to discover its effect upon the foliage. 



June 9. — Made the rounds of all plants sprayed and noted results as 

 follows : 



Potato plants slightly scorched, edges of the leaves curled, larvae of 

 Doryphora mostly on the ground dead, beetles sickly. 



Rose bushes uninjured, or very slightly burned where the leaves were 

 very tender; all larvae killed. 



Cabbage uninjured; all Pieris and other larvae killed. Cucumbers 

 much injured, squash less so; striped beetles killed or vanished. 



Peach and cherry foliage badly scorched, turned yellow. Plum and 

 apple only slightly injured. Other experiments later in the season 

 made with one tablespoonful of the poison to one and one-half gallons 

 of water were not injurious to any except the most delicate foliage, 

 while in most cases it sufficed to kill Sphinx quinquemaeulata and Relio- 

 this armigera on tomato, Darapsa myron, Cidaria diversilineata, Psycho- 

 morpha epimenis, and De mia maculalis on grape, with but slight damage 

 to the foliage. The fruit being "bagged" was not touched by it. 

 Empretia stimulea on plum and pear and Batana ministra on oak also 

 speedily died from eating leaves that had been dampened with it. 



I do not consider these experiments conclusive, as with the heat and 

 drought, vegetation was not by any means in a vigorous condition, and 

 therefore more liable to injury from poisonous applications. It is a 

 most convenient preparation and leaves no sediment to disfigure the 



