Cattatliait Untomoloijbt 



Vol. XXXVIII. LONDON, SEPTEMBER, 1906. 



No. 



PRACTICAL AND POPULAR ENTOMOLOGY.— No. 16. 



Thf. Oyster-shell Bark-louse. 



by tennyson d. jarvis, ontario agricultural college, guelph. 



The purpose of this article is to place before the fruit-growers and all 

 interested in practical entomology, the main facts regarding the life- 

 history, habits and appearance of the Oyster-shell Bark-louse Scale, and 

 of the scales which are often mistaken for it. The damage done by this 

 scale of late years has attracted so much attention, and so many enquiries 

 have been received concerning the best methods for its eradication, that it 

 is hoped earnest efforts will be made at once by all concerned to get it 

 under control. 



The Oyster-shell Bark-louse ( Mytilaspis pomorum) is widely 

 scattered throughout the orchards of Ontario, and the damage done by it 

 is very considerable over the Province and rapidly on the increase. 



Although of European origin, it has been known in America for more 

 than a century, and has gradually spread throughout the larger portion of 

 North America. 



Fu;. 30.— The Oyster-shell Bark-louse. 



This scale is a very serious pest in orchards which are neglected and 

 badly treated, but experience has shown that with careful treatment it can 

 be readily kept in check. It has been found to occur on the following 



