The !N^ew York Plum Scale. 



121 



recently appeared in destnictive numbers in Canada, It is also 

 more generally distributed over our state than was suspected when 

 we wrote Bulletin 83. We have received it from Aquetuck, Hector, 

 Schoharie (on Prunus simoni\ Eastwood and Penn Yan, K. Y. 



Its food- jplants. — The insect still remains par excellence a plum 

 pest, yet several quince and apple trees have been seriously injured 

 by it. A possible source of infestation for some of the orchards 

 near Geneva was found to be an ash grove which was very badly 

 injured in 1894 by a Lecanium which is apparently the same as the 

 •one working on the plum trees. The grove was also badly injured 

 this year, the leaves all dropping off during the summer. 



Probably the Lecaniums found in such large numbers on maple 

 and other forest tre*es in^different parts of the State are distinct 

 from the plum Lecanium. 



Its natural enemies. — The small, black, elevated, smooth, para- 

 sitized scales described in Bul- 

 letin 83, p. 693, were very nu- 

 merous last spring, and we bred 

 many of the minute four-wing- 

 ed flies. Mr. L. O. Howard has 

 determined them as Coccoplia- 

 gus lecanii Fitch, a Chalcid 

 which is common in many parts 

 of the country and attacks sev- 

 eral different kinds of Lecani- 

 ums. This little foe proved a 

 valuable allv of the fruit- 

 grower last spring, as we 

 found a considerable percent- 

 age of the scales parasitized. 



From several different 

 sources we have learned that 

 the twice-stabbed lady-bug 

 beetle was verv numerous in 

 the infested plum trees this year. Several groups of the spring 

 skins (Fig. 47) shed by^ their larvse when they pupate, have leen 

 sent in by plum growers. Protect these little lady-bugs, as they 

 are doing valiant service in the extermination of this pest. 



47. 



-Spiny larval skins of lady-bug beetles, 

 natural size. 



