Allograpta

Mengual, Ximo, Ruiz, Carlos, Rojo, Santos, Ståhls, Gunilla & Thompson, Christian, 2009, A conspectus of the flower fly genus Allograpta (Diptera: Syrphidae) with description of a new subgenus and species, Zootaxa 2214, pp. 1-28 : 12

Key to the subgenera and species groups of Allograpta

1. Metasternum pilose; plumula present and well developed ........................................................................................... 6

- Metasternum bare; plumula absent or very short.......................................................................................................... 2

2. Wing extensively bare basally; antennal pits confluent................................................................................................ 4

- Wing completely microtrichose; antennal pits separate. Alula narrow, narrower than cell BM .................................. 3

3. Face with abrupt tubercle; abdomen parallel-sided (fig. 3) ............................................................................ Costarica

- Face with indistinct or no tubercle (fig. 9–10); abdomen petiolate (fig. 5) .............................................. Rhinoprosopa

4. Alula narrow, as wide as costal cell; male broadly dichoptic; wing without distinct apical macula .............................. ............................................................................................................................................ Allograpta , ventralis group

- Alula broad, broader than costal cell, as broad or broader than cell BM; male holoptic; wing with distinct apical brown macula ................................................................................................................................................................ 5

5. Face produced anteriorly; oral apex distinctly more prominent than antennal bases; oral opening 3.5 times longer than broad (fig. 6); large flies, 13 mm or greater ................................................................................................ Antillus

- Face straight, not produced anteriorly; oral apex distinctly less prominent than antennal bases; oral opening only about 2 times as long as broad; small flies, 6 mm or less ................................................ Allograpta , alamacula group

6. Face produced forward; oral apex distinctly more prominent than antennal bases; oral opening 3 or more times lon- ger than broad; facial tubercle high, distinctly differentiated (fig. 7) .................................................................... Fazia

- Face straight, not produced forward; oral apex distinctly less prominent than antennal bases; oral opening only about 2 times as long as broad; facial tubercle usually low (except armillata ), not differentiated dorsally (figs. 1, 8) ........ 7

7. Abdomen oval, with 4 pairs of large round maculae (fig. 4); large flies, 13 mm ..................................... Claraplumula

- Abdomen elongate, tapering, usually with fasciae and/or vittae (fig. 1); smaller flies, usually 10 mm or less ............. .............................................................................................................................................. Allograpta , obliqua group