206 ORCHARDS. 



bark louse {Aspidiotus Rarrisii, Walsh). The color of the 

 scale is dirty white, and its form is irregular, being usually 

 egg-shaped ; but however variable its outline, it is always 

 quite flat, and causes the infested tiees to wear the appear- 

 ance of figure 1, while the minute eggs which are found un- 

 der it in Winter time are invariably blood-red or lake-red. 

 This species has scarcely ever been known to increase suffi- 

 ciently to do material damage, for the reason doubtless that 

 there have, hitherto, always been natural enemies and para- 

 sites enough to keep it in due bounds. 



The second species, which is known as the oyster-shell 

 bark louse (Aspidiotus conchiformis, Gmelin), is by no means 

 harmless, however, for it is one of the most pernicious and 

 destructive insects which the apple-grower in the Northern 

 States has to contend with. This species presents the appear- 

 ance of figure 2, and may always be distinguished from the 

 former, by having a very uniform muscle-shaped scale of an 

 ash-gray color (the identical color of the bark), and by these 

 scales containing, in the Winter time, not red, but pure w^hite 

 eggs. 



"There is scarcely an apple orchard in North Illinois, in 

 Iowa, or in Wisconsin, that has not suffered more or less from 

 its attacks, and many a one has been slowly bled to death by 

 this tiny sap-sucker. It was introduced into the Eastern 



,«gv^r?cg^^^^gBsc^5:g^igas:>;cag^M rr-r> iL|inii-| States morc than twcn- 



JJ7, ^ iL_ rope, and had already 



^i^^i^si^^^^^*^^^^^^-^''^^-^^'^""^ reached as far west as 



Wisconsin in 1840 from the districts bordering on ' Lake 

 Michigan. It occurs at the present time in Minnesota and 

 Iowa, but whether or not it extends westward beyond the 

 Missouri river, there are no data to show. 



"Remedies. — Small trees can be easily managed, as the 

 terminal twigs can be reached and rubbed with strong soap 

 water or syringed with the same. But alkaline washes will 

 have little effect unless applied about the time the eggs are 

 hatching, and the young lice are cowling over the limbs, 

 which happens during the last of May or early in June. 



