246 Agricultural Experiment Station, Ithaca, N. Y. 



when the insect appeared in enonnous numbers early in the 



spring of 1891, fruit growers were at a loss what to do and how 

 to do it; and entomologists could only suggest methods wliich 



seemed practicable. In most cases the attempts to combat the 

 pest were begun too late; most of the damage had been done, ihe 

 fruit and new growth being severely blighted; the nymphs had 

 covered themselves with honey-dew, and the very active summer 

 adults had appeared. After several unsuccessful attempts with 

 various substances such as kerosene emulsion, solutions of whale- 

 oil soap, fir-tree oil, and carbolic acid, and I^ondon pui-jile and 

 Paris green, the afflicted fruit growers gave up in despair. 

 Nothing seemed to check the pest. They saw the leave:^ and 

 most of the fruit fall before midsummer; and some of their trees 

 were left in a dying condition, while others presented a blighted, 

 blackish, desolate appearance. ITruit growers reported two causes 

 which rendered their efforts ineffectual. These were peculiar 

 places in the habits of the insect. First, the nymphs 'Aer*^ 

 so completely enveloped in honey-dew that none of the insecti- 

 cides reached them. Second, the activity of the summer adults 

 rendered it impossible to reach them with a spray; as soon as 

 the first spray struck a tree, the adults arose instantly and ilew 

 to some distance, remaining awaj' till the spraying ceased. 



During 1892, the pest has done no perceptible dam'age in 

 orchards which it devastated last year. Fruit gTowers noticed 

 that the pest considerably decreased in uumbers later in the 

 season last year. This decrease and the scarcity of the insect 

 this year was probably due principally to the fact that the inswt 

 feeds almost exclusively upon the tenderest leaves and branches 

 of the trees. As hardly any new growth was formed and as most 

 the leaves fell off early in the season, the insc^ct was thus 

 deprived of its favorite food and consequenily its increase 

 checked. So great was the decrease that but very few of the 

 lubernating adults appeared. On this account we tried no 

 exjjeriments to destroy the adults in their winter hiding places. 

 It seems practicable, however, that a thorough washing of the 

 trunks and larger branches of the trees in winter with kerosene 

 emulsion (at least five per cent kerosene) or a strong soap solution, 

 would destroy many of the adults. 



