184 Forty-seventh Report on the State Museum 



The early spring did not bring to notice, either through 

 personal observation or that of my correspondents, the usual 

 number of injurious insects. The earliest to claim attention, were 

 the aphides, or plant-lice — more or less abundant every year, 

 but in some seasons becoming very numerous and correspond- 

 ingly destructive. 



The opening of the apple-tree buds in early May was attended 

 with such an unusual abundance of the apple-tree aphis. Aphis 

 mali Fabr., as to excite apprehension of their effect upon the 

 coming fruit crop. Many letters were sent to me in relation to 

 them. The necessity of preventing their increase by spraying 

 was urged on my correspondents, unless a heavy and continued 

 rain should occur before they would be sheltered by the leaves — 

 say within ten days or a fortnight after their hatching, Mr. C. 

 C. Risley, Chairman of the Executive Committee of the Hop 

 Growers Association, of New York, writing under date 

 of May 9th, stated that hop growers were reporting 

 large numbers of plant-lice on the buds and blossoms of fruit 

 trees and on rose-bushes, recalling the conditions existing 

 in the spring of 1886, in which year the hop crop of the State of 

 New York was almost wholly destroyed by the hop-vine aphis. 

 This year the fruit trees seemed even more infested than they 

 were at that time. He especially wished to know what signifi- 

 cance, if any, this might have with respect to hop injuries the 

 present year. f 



Answer was made that the past winter had apparently been 

 very favorable for the protection and preservation of aphis eggs, 

 and unless the young, recently hatched or now hatching could 

 be speedily destroyed by a heavy rain fall, which, at this stage of 

 their existence, is so fatal to them, we would, in all probability, 

 find the present year characterized by an abundance of aphides 

 equal to that of 1886. It was therefore recommended that, if 

 natural causes did not intervene to prevent this multiplication, 

 the hop growers, on the first appearance of the insect in their 

 yards, should proceed to kill them by proper spraying before 

 they could produce new generations and extend over the entire 

 yards. Directions for spraying with kerosene emulsion — per- 

 haps the best insecticide for use against this insect — and how to 

 make the emulsion, accompanied the letter. 



