13 



Fig. 19. Winged and wingless Aphis — 

 greatly enlarged. 



Fig. 21. Woolly Aphis of the apple ; 

 winged form, greatly enlarged ; a 

 grouj) of young lice magnified ; a 

 twig showing injury to bark. 



Fig. 20. Woolly Aphis of the apple ; 

 much enlarged, except twig. 



Fig. 22. Apple-root Aphis ; a distortions on 

 a root ; b, wooly wingless form ; c, winged 

 Aphis — greatly enlarged. 



SCALE INSECTS. 



The most dangerous enemies of fruit-trees are undoubtedly the Scale 

 Insects, of which we have several destructive species in Canada. The 

 worst of these is certainly the notorious San Jose Scale (Aspidiotus per- 

 niciosus), Fig. 23, which is now firmly established in the Niagara fruit 

 district and in the Counties of Essex and Kent ; it will probably also be 

 found in some other localities. So much has been published respecting 

 this insect in the Reports of the Entomological Society of Ontario and in 

 the agricultural and horticultural periodicals, and the pest has become 

 so widely known, that it is unnecessary to enter into any details here. 

 While its extermination is hardly to be expected, it can be kept under 

 control and even got rid of in an orchard by persistent and careful spray- 

 ing with the lime-sulphur wash, provided that it is properly made and 



