178 THE CANADIAN ENTOMOLOGIST 



KEY TO THE NORTH AMERICAN SPECIES OF 



AGROMYZA RELATED TO SIMPLEX 



LOEW (DIPTERA). 



BY J. R. MALLOCH, URBANA, ILL. 



The species in this group are distinguished from their allies 

 by the following combination of characters: Body entirely black, 

 with sometimes a metallic bluish or greenish tinge, halteres black, 

 costa ending at or slightly beyond apex of third vein. 



Only five species are known to me, one of which is unde- 

 scribed. 



Key to Species. 



1. Mesonotum with 3 pairs of dorso-centrals 2 



Mesonotum with 2 pairs of dorso-centrals 3 



2. Orbits distinctly shining; 5 pairs of orbitals present; anterior 



pair of dorso-centrals weak. Larvae in twigs of willow. 



N. v.; Ill salicis Malloch. 



Orbits opaque; 7 pairs of orbitals present; all 3 pairs of dorso- 

 centrals strong. Food-plant unknown tamia Melander. 



3. Abdomen witji a distinct bluish tinge; cheek almost linear, not 



over one-eighth as high as eye. Food-plant unknown. 



Md winnemancB Malloch . 



Abdomen glossy black, or at least without bluish tinge; cheek 

 about one-fourth as high as eye 4 



4. Outer cross- vein about half its own length from inner; wings 



barely more than twice as long as broad; frontal and 

 facial orbits glossy. Larva; mining in stems of aspara- 

 gus. N. J.; N. Y.; Va.; 111.; Europe simplex Loew. 



Outer cross- vein at its own length from inner; wings about 2.5 

 times as long as broad; frontal orbits very slightly shin- 

 ing, facials opaque. Food-plant unknown. 

 Ill similata Malloch. 



Male. — Black; head opaque, orbits and triangle slightly shin- 

 ing, thorax and abdomen distinctly shining. Wings clear, veins 

 black. Squamse fuscous, fringes black. Halteres black. 



Frons over one-third the width of head ; ocellar triangle poorly 

 defined, extending almost to anterior margin of frons; posterior 



May, 1918 



