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THE NEW YORK PLUM SCALE (Lecanium cerasifex) 



J. C. Chapais, St. Denis-en-bas 



SUMMARY :— Historical notice.— Classification.— Summary description- 

 Difference in the appearance of female and male scales. — Mating and 

 egg laying. — Hatching and first moves of the young scales. — Fall migra- 

 tion and hibernation. — How to combat the Plum Scale. 



Historical notice. — If I have thought of writing a paper on the New York 

 Plum Scale it is on account of the fact that IMr. Alfred Lebel, of St. Denis, Kamou- 

 raska Co., P.Q., appointed by the Quebec Department of Agriculture last year 

 (1911) to make a thorough inspection of the orchards of the members of the Kam- 

 ouraska County Horticultural Society, has discovered that insect in four of those 

 orchards, in three different parishes. Some of those who will read this paper will 

 find nothing new in what I say about the Lecanium cerasifex, for it is known 

 since many years in Europe and America, and, more specially, since 1894, in Can- 

 ada. But, as it is the first time, I think, that its presence has been observed in 

 Eastern Quebec, I think it is a good thing to draw upon it the attention of the 

 Quebec fruit growers, so as to prevent its spreading in their orchards. 



This pest seems to have been noticed in Vermont in 1866, in Missouri and 

 New York in 1893. It is probably the same scale as the European scale that was 

 named Lecanium corni by Bouche and is Icnown in Europe since 1844. What 

 may have been its first appearance in Canada is mentioned by Fletcher as having 

 occurred in Simcoe County, Ont., in 1894. It is said that it is the same insect as 

 Eulecanium prunastii, a cosmopolitan species, says the Century Cyclopedia, 

 which occurs in Europe, Japan and the United States. 



Classification. — Those who have made a special study of the Plum Scale 

 don't seem to be very sure of its real scientific name. But, after ha\ing read all 

 that has been said about it by Beach, Howard, Sanders, Jones, Bouche, Cockerell, 

 Fitch, Walsh, and Crane, who have respectively called it : Lecanium corni, L. 

 Inglandi, Bouche ; L. inglandisfex, L. cerasifex, Fitch ; L. rugosum, Cock- 

 erell ; L. Americanum, Crane ; European fruit Lecanium, Sanders ; L. pru- 

 mastii, Howard ; — in presence of that variety of names, I adopt the opinion of 

 our late federal entomologist, Fletcher, who \\Tites in his 1895 report, that he 



(1) From the Greek LEKANE, a dish, pot, pan — allusion to the shape of the scale. 



