Key to the known males of the family Fanniidae in Beijing, China
1 Arista long plumose; katepisternal setae 1+2 ( Piezura Rondani); frons much broader than the distance between two posterior ocelli at narrowest point; legs yellow, except tarsi and apical part of femora black; abdomen ground-color reddish-yellow.......................................................................... Piezura shanxiensis Xue, Wang & Wu
- Arista short plumose or nearly bare; katepisternal setae 1+1 ( Fannia Robineau-Desvoidy)............................ 2
2 Abdomen spatulate in shape, becoming narrow basad (Fig. 1A); mid femur with two stout thorn-like av in subbasal part (Fig. 1B)....................................................................... Fannia subpellucens (Zetterstedt)
- Abdomen not spatulate in shape; mid femur without any stout thorn-like av in subbasal part.......................... 3
3 Mid coxa with hook-like spines on lower margin (Fig. 1C, D, E)................................................ 4
- Mid coxa without any hook-like spine on lower margin, or only with stout and straight spine.......................... 6
4 Mid tibia with a tubercle on ventral surface (Fig. 1C); mid coxa with three hook-like spines (Fig. 1C)................................................................................................... Fannia scalaris (Fabricius)
- Mid tibia without tubercle on ventral surface; mid coxa with one hook-like spine (Fig. 1D, E)......................... 5
5 Lower margin of katepisternum without stout spine-like seta; fore tibia yellow at the basal 2/3 and with a long setae cluster on the posteroventral surface (Fig. 1F).................................................. Fannia manicata (Meigen)
- Lower margin of katepisternum with a stout spine-like seta (Fig. 1D); fore tibia entirely black and without long setae cluster on the posteroventral surface............................................................. Fannia fuscula (Fallén)
6 Mid first tarsomere with a basal tooth-like spine (Fig. 1G, H; Fig. 5E)............................................ 7
- Mid first tarsomere without basal tooth-like spine............................................................9
7 Fore tibia with a row of slender pv (Fig. 1I).......................................... Fannia spathiophora Malloch
- Fore tibia without pv row............................................................................... 8
8 Eyes bare; fore first tarsomere with slender and dense light brown setae on ventral surface (Fig. 1J); with two setae clusters between fore and mid coxae (Fig. 1K); cercus with long setae cluster (Fig. 1L)................... Fannia barbata (Stein)
- Eyes with fine brownish hairs; fore first tarsomere without slender and dense seta on ventral surface; without setae cluster between fore and mid coxae; cercus without setae cluster.................................... Fannia hirticeps (Stein)
9 Hind coxa on posterior surface with setae................................................................. 10
- Hind coxa on posterior surface bare...................................................................... 15
10 Abdominal tergites 3 and 4 each with three black spots.................................. Fannia leucosticta (Meigen)
- Abdominal syntergite 1+2 to tergite 4 with median stripes or triangular vittas even without any mark.................. 11
11 Mid tibia with two or more pd ..........................................................................12
- Mid tibia with one pd ................................................................................. 13
12 Hind tibia with three to six av and four to six ad; mid femur without notch in distal area; mid tibia without slender seta on ven- tral surface........................................................................... Fannia dupla Nishida
- Hind tibia with two av and one ad; mid femur with a notch in distal area; mid tibia with numerous slender setae on ventral sur- face (Fig. 6E)........................................................................ Fannia papei sp. nov.
13 Lateral part of abdominal tergites yellow, with thin pollinosity.......................... Fannia canicularis (Linnaeus)
- Abdomen black, with dense greyish-blue pollinosity......................................................... 14
14 Abdominal syntergite 1+2 to tergite 4 each with one inconspicuous median inverted triangular vitta, tergite 5 with one narrow median stripe; hind femur with two long av in distal 1/3 (Fig. 1N); hind tibia with one row of p (Fig. 1M), and with one row of ad, irregular in length (Fig. 1N).................................................... Fannia lepida (Wiedemann)
- Abdominal syntergite 1+2 to tergite 5 each with one median longitudinal stripes; hind femur with four long av on distal 1/3; hind tibia without p and with one ad ........................................................ Fannia prisca Stein
15 Hind femur with a setae cluster on posteroventral surface in distal 1/3 (Fig. 1O)......... Fannia metallipennis (Zetterstedt)
- Hind femur without setae cluster on posteroventral surface in distal 1/3.......................................... 16
16 Hind tarsomeres stout (Fig. 2E); pra 1; thorax and abdomen ground-color gloss black (Fig. 2A, B); mid femur without notch in distal area...................................................................... Fannia carbonaria (Meigen)
- Hind tarsomeres not stout; pra 2; thorax and abdomen with light gray pollinosity; mid femur with a notch in distal area........................................................................................ Fannia postica (Stein)