THe HyMENOPTERA OF MINNESOTA We 
NOMENCLATURE OF WING PARTS IN THE DRAWING OF 
Diastrophus nebulosus 
OLD SYSTEM COMSTOCK-NEEDHAM SYSTEM 
Marginal cell SO ar ZiaGl IAP Ie, 
Areolet Rats 
CYNIPOIDEA 
(Gall flies ) 
The members of this superfamily are, for the most part, typical 
gall makers. The peculiar growths seen upon oak and various other 
trees are largely the work of Cynipids; the different galls in oaks, par- 
ticularly, are the work of members of this family. Some of these oak 
galls are designated as follows: Fibrous oak apple, spongy oak apple, 
larger empty oak apple, smaller empty oak apple, bullet gall, giant oak 
gall. On the blackberry also we have the pithy blackberry gall, and in 
the rose, the mossy rose gall. Lack of space forbids a detailed descrip- 
tion of these galls. 
The group may be subdivided into three divisions. (a) True gall 
flies, whose eggs are laid in plant tissue and whose early stages are 
passed within galls, Cynipidae. (b) Iniquilines or guest flies; these 
may be referred to as tenants or dwellers in another man’s property ; 
and (c) Parasites, living in the interior of the bodies of other living 
insects, chiefly aphids or the larva of Diptera. This latter division is 
represented by the family Figitidae. 
Guest gall flies resemble closely the true makers of the galls, and 
Kellogg states conjecturally that the guest species may be a degen- 
erate, loafing scion of the working stock. 
Over 200 years ago, Malphigi advanced the theory that these galls 
were caused by the injection of a fluid into the plant. Previous to this, 
it was supposed that the galls were a purely vegetable production and 
that the maggots found therein were due to spontaneous generation. 
Reamur came to the conclusion that Malphigi’s views were in part er- 
roneous and that the gall was not due to any fluid but to irritation 
of tissue when stung, and by the presence of the egg. 
Later studies of the ecology of these insects, while still leaving 
much to be learned, indicate that the mere presence of the eggs or 
the injection of fluid by the parent do not necessarily of themselves 
