352 PROCEEDINGa Ob THE NATIONAL MUSEUM vol. im 



the five species keying out at couplet 10 (viridula group). These are 

 large dark species that may have a metallic sheen to the mesonotum 

 and abdomen. Of the five, four are Neotropical, which seems to ac- 

 count for the higher proportion in North America. There are two 

 species in the Palaearctic region. A. salicifolii Collin is not found 

 north of Israel and A. guercus Sasakawa occurs in Japan. 



Key to the described species of Agromyza 



1. Mesonotum with two or three well-developed postsutural dorsocentrals plu, 



none to several small postsuturals; a presutural dorcocentral, when presents 



small and posterior to the presutural seta 2 



Mesonotum with four strong well-developed dorsocentrals, one presutural 

 and three postsutural, the presutural at least slightly anterior to the 

 presutural seta 19 



2. Vein Mn-2 at or nearest the wing tip; midtibia medially without postero- 



lateral setae 3 



Vein R4+5 nearest the wing tip; midtibia medially with one or two postero- 

 lateral setae 6 



3. Mesonotum dull, grayish pollinose; at least three well-developed postsutural 



dorsocentrals 4 



Mesonotum shining black; two well-developed postsutural dorsocen- 

 trals varifrons 



4. Femora, tibiae, and tarsi yellow; vein Mn-2 ending only slightly nearer the 



wing tip than R4+6 (figs. 4, 17) 5 



Femora, tibiae, and tarsi dark brown to black, except for foretibia being 

 yellow distally; vein Mi+2 ending at wing tip rubi 



5. Body with all setae yellowish; dorsal upper-orbital arising from black ex- 



tending from vertex (fig. 14) pallidiseta 



Body with all setae black; dorsal upper-orbital arising from yellow (fig. 5). 



aristata 



6. Mesonotum and scutellum subsliining to dull black, somewhat grayish 



pollinose, with or without a greenish sheen; larvae mine dicotyledons . . 7 

 Mesonotum and scutellum shining black; larvae mine grasses 14 



7. Thorax and abdomen yellow or light brown; femora mostly yellow ... 8 

 Thorax and abdomen very dark brown or black, with or without a greenish 



sheen; femora predominately dark brown 9 



8. Third antennal segment and maxillary palpus yellow diversa 



Third antennal segment and maxillary palpus brown canadensis 



9. Tibiae and tarsi dark brown or black 10 



Tibiae and tarsi yellowish reptans 



10. Mesonotum, scutellum, and abdomen with a greenish sheen 11 



Mesonotum, scutellum, and abdomen without a greenish sheen, subshining 



or dull brown or black 12 



11. Upper-orbital setae subequal in length (fig. 20) viridula 



Upper-orbital setae unequal in length, the ventral about 1.5 times as long 



as the dorsal (fig. 10) inaequalis 



12. Calypter with margin and fringe white 13 



Calypter with margin and fringe yellow centrosemae 



13. Anepisternum entirely dark brown or black frosti 



Anepisternum with a narrow yellow dorsal margin currani 



