6'^ Eighteenth Report State Entomologist of Minnesota — 1920 



Koch was the first to recognize tribes and arranged the thirty 

 genera then known into twelve tribes, but unfortvniately left no 

 descriptions of them and they remain as nomcna nuda. In a 

 previous contribution we attempted to interpret them as far as 

 possible and give Koch the credit we can, by the recognition of 

 his thoughts in our bibliographies, at least. Passerini (1863) first 

 recognized subfamilies and submerged the tribal thoughts of 

 Koch. Buckton (1876) made use of the subfamily terms of Pass- 

 erini in a tribal sense. Thomas (1878) used the tribal endings 

 and recognized the two tribes Aphidini and Siphonophorini. 

 Mordwilko (1908) first recognized groups of tribes and gave the 

 term Aphidina to the group under consideration. Mordwilko was 

 not always clear in the use and distinction between tribe and 

 group and sometimes uses the group term in the sense of tribe. 

 Van der Goot (1913) recognized twelve tribes but makes use of 

 Mordwilko's group endings and gives the group under considera- 

 tion as Siphonophorina. Oestlund (1919) gave the group divi- 

 sions higher than tribe in the sense of Mordwilko, of which 

 Aphidina is one. Baker (1920) goes back to the tribal division, 

 not recognizing the group, and reduces the number of tribes in 

 the family to fifteen. 



That we have a score or more tribes in the family appears 

 now to be well understood and recognized. Arrangement of the 

 tribes into groups follows naturally from the attempt to trace 

 their inter-relationship. Such groups are not necessarily super- 

 tribes tho eventually they may work out as such. In the present 

 stage of knowledge they had better be considered as supple- 

 mentary categories whose full status is not yet clear. Mordwilko 

 seems to have used them in this sense. They appear rather to 

 represent epochs or periods in the evolution of the family, as 

 may be seen from the following arrangement of the tribes of the 

 subfamily Aphidinae : 



IV. Aphidina •■ Aphidini M_vzini-Macrosiphini 



III. Callipterina * Calaphidini 



* * Callipterini 



* Drepanosipliini 



II. Chaitophorina ... Pterocominini * 



* Chaitophorini * 



* Vacunini * 



I. Lachnina Lachnini Ptcrochloriiii 



