REPORT OF THE STATE ENTOMOLOGIST IO/I3 79 



APPENDIX 



A STUDY OF GALL MIDGES II 

 ITONIDIDINAE 

 This subfamily comprises by far the larger number of species 

 belonging to the Itonididae and includes practically all the gall- 

 making forms. Species belonging in this group may be recognized 

 by the metatarsus being always shorter than the following segment 

 and by the presence of but three or four long veins in the wings, 

 in connection with the peculiar circumfili, auditory in function and 

 evidently important, of the antennae. These latter structures appear 

 to be present throughout the subfamily, though they do not occur 

 in either the Heteropezinae or the Lestremiinae. Species of the 

 two last named groups appear to depend mostly upon various 

 olfactory organs. 



There is great diversity in this subfamily, though its representa- 

 tives possess much in common. Extreme types of development 

 may be seen in Didactylomyia of the Epidosariae, Clinorhyncha 

 of the Lasiopterariae, Cincticornia of the Asphondyliariae, and in 

 a number of the genera of the Itonididinariae. A large proportion 

 of the species in this subfamily, aside from the Epidosariae, display 

 a marked preference for living plant tissues and may be found 

 inhabiting all portions of a plant, leaf and flower buds being 

 favorite points of attack. Many species produce characteristic 

 galls, while in some instances, at least, several forms may occur in 

 the same gall. 



Key to tribes 

 a A crossvein uniting the third vein and subcosta and usually parallel with 



costa Tribe Epidosariae 



aa No distinct crossvein uniting the third vein with subcosta 



b Antennal segments cylindric, the flagellate never binodose in the male 

 c Claws toothed 



d Costa rarely thickly clothed with scales, the third vein well 

 separated from costa; antennal segments usually stalked 



in the male Tribe Dasyneuriariae 



dd Costa thickly clothed with scales, the third vein usually very 

 close to costa; antennal segments cylindric, sessile, not 



produced Tribe Lasiopteriariae 



cc Claws simple 



d Antennal segments cylindric or subcylindric, not elongated, 



usually stalked in the male Tribe Oligotrophiariae 



dd Antennal segments cylindric, elongate, sessile, the ovipositor 



usually aciculate Tribe Asphondyliariae 



bb Flagellate antennal segments usually binodose in the male, circumfili 

 usually greatly produced Tribe Itonididinariae 



