APHIDES OR PLANT-LICE 



73 



pearance as thus seen upon the bark is represented in Fig. 22, 

 a. They are of two sizes, the larger form being generally the 

 more abundant. If you look through a magnifying lens at 

 one of these larger scales you will see it looks like h of the 

 same figure; this is the female scale and on its under surface 

 are a great many small oval eggs (c). The smaller scales are 

 those of the males; when magnified they look like d. 



During the latter part of May the eggs beneath the larger 

 scales hatch into tiny whitish insects that wander over the 

 bark and finally settle down and insert their beaks to suck out 

 the sap. When they have thus become settled they remain in 

 position, gradually increasing in size as the weeks go by. By 

 the end of the season the scaly coverings have been secreted. 



At the time these insects are wandering over the bark they 

 may easily be killed by spraying ^nth kerosene emulsion. 



A closely related insect, 

 the Scurfy Bark-Louse 

 {Chionaspis fur fur a), has 

 been sent in once or twice on 

 the supposition that it was 

 the San Jose scale. This 

 Scurfy Scale is illustrated in 

 Fig. 23. A piece of bark 

 showing the scales, natural 

 size, is shown at a; the male 

 scale somewhat magnified at 

 5, and the female scale at c. 

 The life-history of this spe- 

 cies is quite similar to that of 



Fig. 23. The Scurfy scale"., bark the Oyster-shell Scale,^ and 

 showing scales in position, natural the remedial treatment is the 



size; 6, male scale, magnilied; c, fe- „^g 

 male scale, magnilied. Sd . 



Considerable complaint was made during the summer of the 

 ravages of Aphides or Plant-lice. These insects are always 

 more destructive in dry seasons than in wet ones: the dry 

 weather favors their development and it also prevents the 

 plants from quickly recovering from the injuries inflicted by 

 the insects. Early in the season much injury to apple trees 



