THE CANADIAN ENTOMOLOGIST. 353 



ON THE GEOGRAPHICAL DISTRIBUTION OF SOME COM- 

 MON SCALE INSECTS. 



BY L. O. HOWARD, WASHINGTON, D. C. 



Owing to the extensive commerce in nursery stock and fruits, which 



has been carried on all over the world for many years, it has become a 



matter of very considerable difficulty to form any adequate idea of the 



original Coccid fauna of any given part of the globe. Restriction of the 



importation of diseased nursery stock, and fruit is new, and for years 



plants and fruit, carrying thousands of scale insects, have been landed 



almost daily at most large seaports. It is, however, not too late to 



ascertain many facts of importance, and since the apparent confusion is 



growing worse day by day, it becomes necessary to make an immediate 



endeavour not only to ascertain the original home of all species of 



economic importance, but to place on record all the facts which can be 



ascertained regarding their spread down to^ the present time. Many 



injurious species are still more or less restricted, and the necessity for 



quarantine laws is as great as it has ever been. If horticulturists will 



not demand, for their own personal good, a clean bill of health from 



dealers from whom they purchase plants, it behoves local and State 



governments to pass such regulations as will effectually prohibit the 



introduction of new insect enemies, particularly of this class of scale 



insects. 



To point this moral to which I have more particularly referred in No. 

 3 of Vol. VII. of Insect Life, we have only to glance at the history of 

 several prominent orchard scales, now more or less well-known to most 

 fruit growers. 



The Oyster-shell B-irk-loiise of the Apple {Mytilaspis pomorie/n, 

 Bouche). — This widespread species, now found practically all over the 

 world, so far as our information goes, was apparently originally a 

 European species, at least it was known to European entomologists in 

 the early part of the eighteenth century. At the present day it occurs 

 abundantly throughout the United States and Canada, with the exception 

 of the far south-west. It was imported into the New England colonies 

 at some time during the last century. The first American account of the 

 insect was written by Mr. Enoch Perley, of Bridgeport, Maine, in 1794. 

 By 1835 it had spread through New England; in 185411 was already 

 abundant throughout New York, Pennsylvania and Ohio, and parts of 



