Eleventh Keport of the State Entomologist) 205 



In Fig. 2 of Plate X (after Walsh and Riley) the scales and egg-masses 

 are shown on osage-orange as Lecanium Maclurce, and on maple as Z. 

 acericola, but both are now referred to P. innumerabilis. 



This scale had become very abundant upon the maples in the streets 

 of Brooklyn in 1890, and was reported as having killed a large number 

 of the infested trees.* In 1884, it was excessively abundant and quite 

 destructive over the larger part of the State of Illinois. Further particu- 

 lars of it, and available remedies, may be found in the Sixth Report o)i 

 the Insects of New York, 1890, pp. 141-147. 



The Plum-tree Scale-insect. 



In Plate XI, the plum scale is shown — an apparently new and de- 

 structive plum pest, which has during the past year made its appearance 

 in different localities in the State of New York, particularly in its western 

 portion. Examples of it were received by me on May 14th and r5th 

 from Dr. Collier of the Geneva Agricultural Experiment Station, and 

 from C. M. Hooker and W. C. Barry, of Rochester. No record could 

 be found of its previous occurrence as infesting the plum. On submit- 

 ting it to Prof. T. D. A. Cockerell, of Las Cruces, New Mexico, who has 

 made special study of scale insects, it was determined by him, with a pos- 

 sible doubt, as Lecanium juglandis Bouche. This determination has not 

 been accepted by some entomologists, while as an explanation of differ- 

 ence of opinion in regard to it, it has been suggested that two closely re- 

 sembling species are associated on the infested trees. 



The species of Lecanium are large, conspicuous scales, as may be seen 

 covering the branch in the figure, approaching a half globe in form, and 

 in the season of reproduction, containing within their capacious bodies 

 a very large number of eggs — a thousand, or it may be two thousand or 

 more. From their rapidity of muhiplication they may prove very injuri- 

 ous to the trees that they infest, but, fortunately, their size, and their ten- 

 derness during a portion of their existence, exposes them to parasitic 

 attack and to destruction from certain weather conditions. They are 

 amenable to treatment with kerosene emulsion, and to the methods which 

 will be recommended for the destruction of the San Jose scale. 



Prof M. V, Slingerland, of the Cornell University Experiment Station, 

 has made a study of this insect in the plum orchards of Western New 

 York, the results of which are published in Bulletin 83 of the Station — ■ 

 describing it, narrating its destructiveness, naming the few plants upon 



*Eighth Report on the Insects of New VorJc, 1893, page 177. 



