APPLE-TRUNK BARK-LOUSE ITS WESTERN LIMIT. 33 



have strong confidence that the remedy to which I now resort 

 will keep them freed from the bark-louse But through all this 

 district of country the trees are overrun and dying from these 

 insects, a tree not living but about three years after it becomes 

 badly infested, and on almost every farm several dead trees may 

 be seen, and many more which are so far gone that they can 

 never recover." 



This insect does not appear to have penetrated west, as yet, 

 beyond the districts bordering upon Lake Michigan. I found the 

 orchards upon the Mississippi river free from it, and on a most 

 particular inspection of the trees of Esquire Baldwin, of Farm 

 Ridge, less than a hundred miles west of Chicago, they were found 

 to be wholly uninfested. But that it will gradually extend itself 

 onwards over the entire west, there can be no doubt. And it is 

 to be feared that for some years after its first arrival in each place, 

 it will run much the same career it is now doing on the borders 

 of Lake Michigan, it being common for a noxious insect when 

 newly introduced, to multiply and thrive to a much greater ex- 

 tent than it does subsequently, after it has become fully natu- 

 ralized. 



At the west it is generally supposed that this insect is a new 

 species, peculiar to that section of the country, as no distinct de- 

 scription and account of it is given in works accessible to the 

 mass of readers. And, entertaining this view, my friend Robert 

 W. Kennicott, of West Northfield, Illinois, in a communication 

 read in June last, before the Cleveland Academy of Natural 

 Sciences, and published, with a figure of the young larva, in the 

 newspaper report of their proceedings, names it the Coccus Pyrus 

 Mi. lusj under which name I observe it is since spoken of in some 

 of the western agricultural periodicals. But this insect is cer- 

 tainly identical with the one which we have here at the east, which 

 has all along been regarded as the same which has long been 

 known upon the apple and some other trees and shrubs in Europe. 

 It was first described by Reaumur, in 1738, who found it upon an 

 elm in France; and it appears to have been named Coccus arbc- 

 rum linearis, (which literally means the Linear Bark-louse of 



[Assem. No. 215.] 3 



