UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 826 
Contribution from the Bureau of Entomology 
L. O. HOWARD, Chief 
^#*^Wd» 
Washington, D. C. 
PROFESSIONAL PAPER. 
August 10, 1920 
GENERIC CLASSIFICATION OF THE HEMIPTEROUS 
FAMILY APHIDIDAE. 1 
By A. C. Baker, 
Entomologist, Deciduous Fruit Insect Investigations. 
CONTENTS. 
Superfamily Aphidoidea 2 
Phylogeny of the Aphididae 3 
Key to the subfamilies of the Aphididae 10 
Subfamily I, Aphidinae 10 
Tribe Lachnini 12 
Tribe Thelaxini 20 
Tribe Callipterini 21 
Tribe Greenidemi , 37 
Tribe Setaphidini 38 
Tribe Aphidiui 39 
Subfamily II, Mindarinae 61 
Page. 
Subfamily III , Eriosomatinae 62 
Tribe Eriosomatiui 65 
Tribe Pemphigini 68 
Tribe Melphini 73 
Tribe Prociphilini 75 
Tribe Fordini 77 
Subfamily IV, Hormaphidinae 81 
Tribe Hormaphidini. 83 
Tribe Oregmini 84 
Tribe Cerataphidini 86 
Genera not placed 88 
Probably no group of insects has received more attention at the 
hands of economic entomologists than aphids, or plant-lice. Their 
interesting and often complicated biologies have attracted the atten- 
tion of investigators, not only among entomologists, but among 
workers in the larger fields of zoology and general biology. While 
a large amount of work on the life histories and biologies of aphids 
has been done, corresponding progress in their classification has not 
been made. This is probably due to several causes, such as the lack 
of correlation of biologic and taxonomic facts, and the failure of 
aphidologists to consider sufficiently the results of the work of others. 
On account of the great economic importance of aphids and the 
necessity of their study in the development of control measures, the 
lack of knowledge concerning their systematic relationships results 
in much confusion. Some biologic workers, in fact, do not now at- 
tempt to give the name of the species being studied on account of the 
difficulty experienced in securing correct determinations. 
1 This paper is the first of a series treating the Aphididae. It will be followed by others dealing with 
the economic importance, biologies, and relationships of species in the different genera. 
141613°— 20— Bull. 826 1 
