FORTY-FOURTH ANNUAL REPORT. 137 



ARSENATE OB^ LEAD. 



Arsenate of Lead is sold in the market in two forms — the i)aste and 

 powder. This poAvder is approximately twice as strong as the paste and 

 sells for slightly more than twice as mnch as the paste, so that for a 

 unit of strength, one costs about the same as the other. Generally they 

 have proven to be equally efficient when used at corresponding strengths. 

 Manufacturing companies try to show a remarkable difference between 

 the acid and neutral pastes and should any brand be strictly neutral it 

 should be more staple and safe to use but analj^ses of different brands 

 do not often indicate any decided difference. 



ARSENITB OF ZINC. 



Arsenite of Zinc is a new arsenical Avhich has recently come upon the 

 market and is offered as a substitute for arsenate of lead and Paris 

 green. It is a fluffy white powder and contains the equivalent of forty 

 per cent arsenious oxide and it is said to have a very virulent and rapid 

 action. Tt has received extensive trial in tlie Pacific Coast states and 

 there has been found to be safe to use in connection with Bordeaux mix- 

 ture on the foilage of apples, grapes and potatoes. It should never be 

 used with water alone or in combination with lime-sulphur. California 

 authorities also caution against its use with either molasses or glucose, 



THE USE OF SWEETENED POISONS. 



There are three insects, namely the rose-leaf chafer, commonly known 

 as the "Rose Bug;" the apple maggot and the cherry fruit fly which 

 liave proven to be uncontrollable by the use of any of our ordinary 

 I>oisons. 



The reason for this, in the case of the rose leaf chafer, is that the 

 adults which do the damage have very discriminating appetities and they 

 avoid swallowing as much of the poison as they can and consequently 

 die so slowly that the damage is not prevented. In the case of the apple 

 maggots and cherry fruit flies, the adult insects ordinarily feed very 

 little and have the unique habit of depositing their eggs beneath the 

 skin of the fruit, hence when the larvse hatch they are beyond the reach 

 of arsenicals. 



In efforts to control the "rose chafers" someone conceived the idea 

 of sweetening the poison by the addition of cheap molasses or glucose 

 Avith the hope of inducing them to eat more of it. The results have been 

 so satisfactory that the use of a sweetened poison is a common practice 

 among vineyards wherever the rose chafer is troublesome. 



These favorable results pointed to a possible treatment for apple 

 maggot and cherry fruit fly. Extensive trials made by the New York 

 Cornell Experiment Station in 1913 for Apple Maggot and the past 

 season for the Cherry Fruit Fly demonstrated beyond question that 

 sweetened posions were a successful remedy for them. An extensive trial 

 of sweetened arsenate of lead in the orchard of Benton Gebhart at Hart, 

 this last summer, controlled the cherry fruit fly entirely successfully. 

 On unsprayed trees the fruit Avas very bad, at least half the fruits 

 being affected. On sprayed trees or in the near vicinity of sprayed 

 trees, scarcel}^ a wormy cherry could be found. 



