KEY TO AMERICAN INSECT GALLS II 



Fruit galls. This term is limited to species inhabiting the seeds 

 or fruits and in some cases producing marked deformities. 



Leaf galls. The term is a broad one applying to all deformations 

 definitely associated with leaves. 



Leaf spots. A descriptive term which has been adopted for some 

 leaf galls which are more evident because of the marked discolora- 

 tion than on account of size or elevation. 



Monothalanious. Literally, one chamber; a convenient term used 

 to designate galls inhabited by a larva or larvae in one cell or 



cavity. 



Oak apples. A general term applied to the familiar, large galls 

 on oak produced by the genus Amphibohps and referring in par- 

 ticular to the large oak apple and the empty oak apple. 



Pouch galls are simply pouchlike deformities usually caused by 

 a depression in the leaf surface eventuating in a pouchlike cavity, 

 such, for example, as that inhabited by a number of gall mites. 



Root galls is a term appHed to any swellings upon roots. 



Rosette galls are simply a specialized type of bud gall with the 

 central cell or cells surrounded by a rosette of partly developed 

 leaves. 



Stem or twig galls are deformations restricted to that portion 

 of the plant. 



Subcortical galls are swellings just under the bark and usually 

 occurring upon one side of a twig or stem. 



It is frequently very convenient to be certain of the group to 

 which the gall maker belongs and the following abbreviations are 

 used in the key. 



Acarid. An abbreviation for Acarina and in this work refers 

 particularly to the gall mites or Eriophyidae. The galls produced 

 by this group vary from a simple erineum to a more or less modified 

 pouch gall and are most easily recognized in many cases by the 

 abnormally developed plant hairs and the orifice usually guarded 

 by a fuzzy growth. The presence of extremely minute, four-legged 

 mites is characteristic of these deformities. 



Aphid. An abbreviation for Aphididae or plant lice and in this 

 work applied to the gall-producing forms. Aphid galls are most 

 easily recognized by the more or less distinct orifice and the char- 

 acteristic inhabitants. 



Coleop. An abbreviation for Coleoptera or beetles, the gall- 

 making larvae of which are legless or nearly so and characterized 

 by the possession of a head and well-developed jaws. 



Itonid. An abbreviation for Itonididae or gall midges, a group 



