258 FOREST ENTOMOLOGY. 



Tribe Chermesinse (kennes, a red dye). — The genera of this tribe are 

 varied in their habits, inasmuch as they are coccus-like, bark-feeders, 

 gall-makers, or wool-spinners, and sometimes subterranean. Genera — 

 Chermes. Phylloxera. 



Tribe Rhizobinse. — The genera of this tribe are root-feeders, and 

 hitherto have not been much investigated in the forest. There is a 

 species very common on the dead leaves of Scots pine which may be 

 found throughout the whole of the year, but hitherto I have not dis- 

 covered any name for it. 



In giving an account of the more common and destructive genera and 

 species of arboreal Apliididce, it may be suggested to the student that 

 much valuable information on the habits and structure of these insects 

 might be gained by studying many species of the genus Sijjlwnophora, 

 which are found on many varieties of plants. Thus, for example, Siphon- 

 opiJiora rosce is abundant on roses ; S. ruhi on raspberry ; S. avellance on 

 hazel ; and various other species of this genus are found on our com- 

 mon plants. 



Tribe APHIDIN^. 

 Ge7ms Myzus. 



The chief generic characters are antennae about equal to the length 

 of the body. Cornicles long, tail prominent. Wing venation much 



the same as in a typical 

 aphis. 



n 



% 



Myzus cerasi (Fab.) 



This species is very com- 

 mon on wild cherry or gean 

 of the forest, as well as on 

 the cherry of gardens and 

 orchards. The damage done 

 by the insect is very easily 

 recognised. The injured 

 shoots form a sort of rough 



ns. 250.— Tcrtninal shoot of wild cherry hijurcdb7j rOSette of IcaveS (fi" 250), 



Myzus cerasi. \ o /' 



and the absorbing action of 

 the insects, coupled with the exudation of honey-dew, add a sort of 

 sooty appearance to the damaged shoot. 



