A SYNOPTICAL KEY TO THE APHIDIDAE OF MINNESOTA 
By O. W. OESTLUND 
A synopsis of the Aphididae of Minnesota was published as 
Bulletin No. 4 of the Geological and Natural History Survey of 
Minnesota for 1887. This bulletin has long been out of print as well 
as out of date. The classification of Thomas, Riley, Monell, and 
Buckton, as then usually accepted, was followed. The classification of 
the family has undergone great changes since that time, and the author 
has long had in mind again to present this early effort of his in a 
more modern form. Limit of time and space will not allow a full 
account of the various groups and species as now known to occur 
in the state, but a key is given that will lead the user to the more 
modern name. The practical entomologist and the student have not 
the time or the literature at hand to enable them to follow the many 
changes that have taken place in the names of many of our genera 
and species leading up to a modern phylogenetic view of the family. 
The contibutors to this study of the Aphididae for the last thirty 
years have been many, for America as well as for Europe and other 
parts of the world. Their publications are scattered over a large 
number of scientific periodicals and other publications, which only 
the specialist may be fortunate enough to possess or to know of. 
They are found in various languages, as English, Latin, French, Ger- 
man, Italian, Dutch, Scandinavian, and Russian. To codify this exten- 
sive and varied knowledge, as far as our fauna is concerned, is one 
of the great needs for the present. In a previous contribution by the 
author, in which he endeavored to establish the tribes and higher groups 
of the family as held somewhat differently by Mordwilko, Van der 
Goot, and the author, the statement was made that the groups of tribes, 
there recognized and largely suggested by Mordwilko, are not super- 
tribes but would eventually work out as such. Mordwilko in some 
of his latest works, the Fauna of Russia and Aphids of the Grami- 
naceae, has so regarded them. To be sure he calls them tribes and 
not supertribes, but this is of minor importance, the important thing 
is that they represent natural phylogenetic groups which help us to 
form a conception of the probable order of development of the famity. 
We differ somewhat as to the number and order of these groups, 
but it is out of place to discuss this here. The differences as well as 
the similarities can best be expressed by a phylogenetic tree that 
accompanies this paper. Quite a number of new generic terms have 
