Key to the Micropezidae

of the US

This key appears in the classic and out of print Manual of Nearctic Diptera Volume 2 (thanks for the copy from Judy Semroc). Images were scanned from the Manual as well. The key is unmodified here as I have no access to any updated material since the 1987 monograph. There were 27 known species north of Mexico at that time. There are now 33 species listed in Nearctica (notated on the genera below). Including 16 species in the genus Micropeza. Nearctica lists a genus Neria and I don't know where this falls in the classification.

1  Hind tibia with a row of dorsal bristles. Crossvein bm-cu present or absent. Katepisternal bristles present and often numerous.

                                                                           2

1’ Hind tibia without a row of dorsal bristles. Crossvein bm-cu present, separating cells bm and dm. One to four katepisternal bristles present

                                                                                        CALOBATINAE 4

2  Crossvein bm-cu absent and cells bm and dm confluent; posterodistal angle of cell cup not acute. Fronto-orbital bristles absent. One to four katepisternal bristles present

                                                                          MICROPEZINAE   Micropeza Meigen   3

10 species in Manual

2’ Crossvein bm-cu present and cells bm and dm separate; posterodistal angle of cell cup acute. Fronto-orbital bristles present. Katepisternal bristles numerous in vertical series

                                                                           TAENIAPTERINAE 6

3  One notopleural bristle present. Cell r4+5 open or closed in margin

                                 Micropeza (Micropeza Meigen)

10 species; northern Great Plains southward into Neotropical region

3’ Two notopleural bristles present. Cell r4+5 usually closed and often petiolate

                                                 Micropeza (Neriocephalus Enderlein)

6 species; northern Great Plains southward into Neotropical region

4  Palpus more than twice as long as wide, reaching facial margin. Subcostal section of C long. Male with metathoracic process situated between bases of hind coxae

                                                                                                                    Cnodacophora Czerny

3 species in Manual; northward from Colorado and Illinois (1 species presently listed in Nearctica)

4’ Palpus little longer than broad, not reaching facial margin. Subcostal section of C virtually obliterated by Sc and R1 lying adjacent at tips. Male without metathoracic process

                                                  Compsobata Czerny 5

5  Sternite 6 of male without a process projecting between bases of processes of sternite 5. Female with segment 7 laterally compressed, rounded basally. Body color reddish; thorax wholly pruinose dorsally

                                                                                                                               Compsobata (Compsobata Czerny)

2 species; widespread, mostly northward

(Only six species of Compsobata listed in Nearctica site)

5’ Sternite 6 of male with at least a small process projecting between bases of processes of sternite 5. Segment 7 of female with an earlike lobe basally and cylindrical or flattened dorsoventrally,. Body color black; thorax partly glossy dorsally

                                                                                                      Compsobata (Trilophyrobata Hennig)

13 species; widespread, mostly northward

6  Anterior margin of clypeus with a few short erect setae. Arista bare. Postocellar bristles lacking

                                                                                 Hoplocheiloma Cresson

1 species in Manual; 1 species in Nearctica - different listings

species in the Manual listed only for FL

6’ Clypeus bare. Other characters variable

                                                                                                 7

7  Median part of face broad, flattened, and setose

                                                                                                                             Calobatina Enderlein

1 species geometroma Robineau-Desvoidy 1830 in Manual;

3 species in Nearctica including geometroma

7’ Median part of face narrow and bare

                                                                                          8

8  Cell cup long; CuA2 as long as or longer than free part of A1 and + CuA2

                                                  Taeniaptera Macquart

2 species in Manual; 2 species in Nearctica

T. lasciva Fabricius 1798

T. trivittata Macquart 1835

north to California, Michigan and New York (other species neotropical)

8’ Cell cup short; CuA2 shorter than free part of A1 + CuA2

                                               9

9  Arista plumose (shortly so in Nearctic species). Pruinose frontal vitta broad at each end strongly narrowed anteriorly

                                                                                 Grallipeza Rondani

1 species, G. nebulosa (Loew) 1866 in both sources,

Gulf states

9’ Arista bare (plumose in some extralimital species). Pruinose frontal vitta strongly narrowed anteriorly

                           Rainieria Rondani

1 species R. antennaepes Say 1823 in both sources

Alberta and Nova Scotia south to TX and FL