76 THE CANADIAN ENTOMOLOGIST 



lights. In the meantime, however, we must rely upon such 

 remedies as tests have proved worthy of recommendation.* 



A PARTIAL KEY TO SPECIES OF THE 

 GENUS AGROMYZA (DIPTERA). 



' BY J. R. MALLOCH, URBANA, ILL. 



It is my intention to publish keys to species groups of the 

 genus Agromyza as aids to the identification of the numerous forms 

 which have been described or recorded from North America. Up 

 to the present time I have seen nearly ninety species of the genus 

 from the United States. In order to make it possible for a serial 

 magazine to present keys to this large number of forms I have 

 divided the genus into arbitrary groups, the characters used in 

 these divisions being enumerated in each instalment on the key. 



The present key includes all species which have the scuteUmn 

 conspicuously yelloiv either entirely or in part, contrasting strikingly 

 with the disc of the thorax. The halteres in all the species are pale 



1. Antennae with at least the entire third joint black (cf. 



variata) '..2 



Antennae entirely yellow or at most with the third joint 

 partly infuscated 5 



2. Frons black, only frontal lunule yellow. Food-plant un- 



known. Mexico; New Mexico xanthophora Schiner. 



Orbits black, interfrontalia reddish yellow; very small species 



(.75 mm.); body with exception of scutellum black; legs 



black, only knees yellow. Food-plant unknown. Wash.; 



Ill interfrontalis Melander . 



Frons yellow, ocellar region and sometimes orbits partly 

 black; body with more than scutellum yellow 3 



3. Palpi and legs black. Food-plant unknown. 



Texas quadrisetosa Malloch . 



Palpi and greater portion of legs yellow 4 



4. Wings clear. Food-plant unknown. Wash.; Alaska; B.C.; 



Ill {longispinosa Malloch) pacifica Melander. 



*For further reference on this subject see Stingerland's "Trap-lanterns or 

 Moth-catchers." Bull. No. 202, Ithaca, N.Y., 1902. 

 March, 1918 



