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in previous seasons in small numbers, but it has not been taken even in 

 the adult form, in this locality till this summer, so that it seems more 

 likely that it has been introduced in some way quite recently. 



TESTS OF ARSENITE OF AMMONIA. 



During the month of May I received instructions from Mr. Howard 

 to make tests of an insecticide put on the market by Fr. Jac. Andres, 

 of 25 Pearl street, New York, under the name of arsenite of ammonia, 

 as agent for the Caspar Schneider Chemical Works. In due time the 

 samples came from the New York firm and I proceeded to make such 

 tests as were possible to determine both the effects upon various kinds 

 of plants and its effectiveness in killing insects. 



On the morning of May 30, 1890, between 9 and 10 o'clock of a hot, 

 sunny day, I sprayed the following plants with a view to giving a 

 thorough test of the effect on foliage : 



Squash vines infested with Diabrotica vittata. 



Cucumber vines infested with Diabrotica vittata. 



Potato vines infested with Epitrioc cucumeris. 



Plum, Cherry, Box-elder, Willow, Elseagnus, Elm, Mountain Ash, 

 Birch, Apple, Baspberry, beans, grass, and clover. 



The results were watched closely for a number of days but the record 

 of June 2 gives the results for the entire set. On that day a careful 

 examination was made of all the plants that had been treated and it 

 was found that in no case could there be found any injury to the foliage, 

 except possibly a slight injury to the elm and the beans, but the injury 

 was so slight, if any, in these cases that it could hardly be charged with 

 certainty a.gainst the arsenite. The solution in this case was as given 

 in the directions, a tablespoonfui to an ordinary pailful of water, and 

 the conclusion was that with this strength it could be applied without 

 danger to any of the above-named plants. 



On the squash vines and cucumber vines the beetles seemed much 

 less abundant, but I was unable to find any dead insects around the 

 vines. The hills treated, however, remained quite free from further 

 trouble from these insects, while others in the vicinity were seriously 

 affected. The failure to find dead beetles under the treated plants 

 might easily result from the insects flying away after eating the poison 

 to places of shelter and dying there. The same was true of the flea- 

 beetle affecting potatoes. The beetles seemed much less abundant, but 

 no dead ones could be found under the treated vines. 



While it was so late in the season that it was not expected that this 

 test would give any definite results as to the effect on the codling moth, 

 it is worthy of mention that the branches of the apple tree sprayed 

 with the arsenite were loaded with apples, while the other portions of 

 the tree were much less fully loaded. 



The apples also of this portion were quite free from worms, though 

 in the late fall they were of course exposed to the action of the second 



