A Plum Scale. 685 



or four years, until it has now reached a point where it threatens 

 the destruction of some of the finest orchards in these counties. 



We have found but a single reference to a L,ecaniura attacking 

 plum trees in the east prior to 1894. In 1866, a correspondent in 

 Vermont sent a plum branch containing many of the scales to Mr. 

 Walsh, then editor of the " Practical Entomologist " (p. 89 and 

 100), for identification. Mr. Walsh's notes on the eggs agree so 

 closely with our observations on the Plum Scale this season as to 

 indicate that the Vermont scale was the same insect. Recently, 

 Miss Murtfeldt (Bull. 32, Div. of Ent. of the U. S. Dept. of Agr., 

 p. 41-44) has recorded the appearance in destructive numbers in 

 1893 of ^ Lecanium on plum and peach in Missouri. This Mis- 

 souri Plum Scale seems to difier slightly in some of its character- 

 istics and in its life history from our New York vScale, but may 

 not the difference of 5 degrees in latitude between the two locali- 

 ties account for these differences between the insects ? Mr. 

 Fletcher recently found a Lecanium, probably identical with our 

 New York species, on plum at Queenstown, Canada.* Thus, 

 while we believe that this new plum pest occurs in many orchards 

 outside our state, no definite conclusions can be drawn from the 

 meagre and indefinite evidence thus far reported. 



We have also received the insect from Utica and from Pratts- 

 burg (Steuben Co.) N. Y., but it has not 3'et become serious in 

 these localities. The only localities, so far as we know, where the 

 pest is now present in alarming numbers is in several of the large 

 orchards near Geneva, Rochester, and L,ockport. Nearly all of 

 the owners of these orchards are thoroughly alive to the necessity 

 of checking this pest at once, and the work of extermination has 

 already begun in some of the orchards. 



How long the insect has been present in these localities, is not 

 known. It was seen in considerable numbers in Geneva orchards 



*Mr. Cockerell will describe this scale as L. rugosum in the coming Feb- 

 rurary number of the " Canadian Entomologist." He says it agrees closely 

 with the New York Scale in microscopic characters, but differs slightly in 

 form. The form of these scales depends so much upon the time when they 

 are collected and killed, whether they are crowded together on the branch 

 or not, and other factors that the mere form of the dead females or their 

 shells does not furnish a sure criterion by which to determine the names of 

 many of the Lecaniums. 



