27 



then increased steadily and Las been spreading gradually over the peach 

 orchards of the Middle, Southern, and Eastern States and appears to 

 be at present most abundant and most widely distributed in the State 

 of Maryland. Whether its original home was the East or West is dif- 

 ficult to ascertain, though its greater abundance in the tier of States 

 bordering the Atlantic seems to indicate that its original home was in 

 the region south of New York and north of the Potomac River and that 

 from this region it had been distributed with cuttings and young trees, 

 and to a lesser degree through the agency of birds and insects, over all 

 the infested regions. 



Until recently this scale has been considered a specific enemy of the 

 peach, but while studying it in connection with the large amount of 

 material of various species of Lecanium infesting our fruit trees as well 

 as those of our forest trees and shrubs, which had accumulated during 

 the last twenty years in the collection of the Department of Agricul- 

 ture, I was struck by the great similiarity of certain small scales, dif- 

 fering from each other and from the peach scale but slightly in size and 

 general appearance, and found, after preparations and examinations of 

 scales from various plants and localities, that all of 

 them belong to the same species and that the slight 

 and superficial differences appear to be due to the 

 difference in the food plaut on which they were living 

 and to a greater or less extent also to the age of the 

 specimens when found. 



Food-plants: Most frequently, besides on the peach, 

 they were found on various kinds of plum. They were Fig 9 .- LeC anium 

 found on cultivated plums atKirkwood,Mo. ; Chambers- nigrof as datum: 

 burg, Pa, ; Newark, Del. ; Harmons, Md., and Knoxville, £^5$*T 

 Tenn.; on a native plum at Ruina, 1111; on damson 

 plum at Baltimore, Md.; Primus simonii at Waynesboro, Pa, ; and on 

 wild goose plum at Augusta, Ga. They were also equally common on 

 Acer saccliarimim at Boston, Springfield, Holyoke, and Deerfield, Mass.; 

 at Poughkeepsie and Ithaca, K Y.; Paterson, N. J.; Richmond, Ohio, 

 and western Ontario, Canada. At Reading, Mass., on Acer pseudo- 

 platamis, and at Pine City, Ga,, on Acer rubrum-drummondi; at St. 

 Louis, Mo., on apple, and at Washington, D. C, on Crataegus; on syc- 

 amore at Kirk wood, Mo.; on Bumelia and Lindera benzoin at Wash- 

 ington, D. C; on olive at Crescent City, Fla.; and on Yaccinium at 

 Manatee, Fla. 



Considering the various trees and shrubs on which this species has 

 been found, the indications seem to point strongly to our native plums 

 as original food plants. 



Living specimens, when being crushed, emit a disagreeable odor. 



As late as 1895 this species has been considered as being identical 

 with the European Lecanium persicce Mocleer, but in order to settle this 

 important point definitely, specimens of it were transmitted through 



