CHERMESID^ IN RELATION TO BRITISH FORESTRY. 133 



1907-8, pp. 1-13, 1 19-148). These papers did much to spread 

 a more accurate knowledge of the group in this country. Since 

 that date a great advance in our knowledge of this family has 

 been made, but the results of these recent continental researches 

 are not generally available to foresters. My researches and 

 observations on the Chermesid?e have enabled me to test these 

 results, and the statements on the life-histories refer to my 

 observations for this country unless otherwise stated. 



The most recent classification raises the Chermes group to 

 family rank, and divides the genera of that family into two 

 tribes, as follows : — 



Family CHERMESID.E. 



Tribe Pineini. 

 Genus Ptfieus, Shimer. 



Tribe Chermesini. 



Genera Chermes, Borner ; Gilleitea, Borner; Aphrastasia, 

 Borner; Dreyfusia, Borner; Cnaphalodes, Macquart.; 

 and Cholodkovskya, Borner. 



For convenience in treatment, I group the genera according 

 to their hosts. The following genera have been found in 

 Britain : — 



Spruce-Larch Series. 



Genera Chermes. 



Cnaphalodes. 



Spruce-Pine Series. 

 Genus Pineus. 



Spruce-Silver Fir Series. 

 Genus Dreyfusia. 



II.— LIFE-HISTORIES. 

 1. Spruce-Larch Series. 



The species of two genera of the Family Chermesidae, namely, 

 Chermes, s. str., and Cnaphalodes, are found on spruce and 

 larch. In each genus there is one, or probably two, species 

 whose cycles are passed on both spruce and larch, while there 

 is one species which completes its life-history on spruce only. 



