Pseudacteon Coquillett 1907
Creators: name: Liu, Guang-Chun
name: Disney, R. Henry L.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Phoridae
Pseudacteon

description: Genus Pseudacteon Coquillett
Pseudacteon Coquillett, 1907: 208. Type species: P. crawfordi Coquillett, 1907.
Diagnosis. Small species. Frons trapezoid, with median furrow, with 2 proclinate and 2–4 reclinate supra-antennal setae, and 4–4–4 frontal setae. Flagellomere 1 oval or conical; arista apical, short. Palpus rod-shaped, sometimes expanded.Anepisternum bare. Scutellum with 2–4 setae. Legs not slender. Fore tibia without isolated setae, fore tarsus normal, tarsomeres in variable ratios. Mid tibia without isolated setae, with a dorsal setal palisade, which is usually not complete. Hind tibia with dorsal setal palisade and posterodorsal cilia. Wing costa short, vein R 2+3 wanting, with a small angulate thickening near apex. Abdomen short, tergites II and VI in male generally a little elongated. Male terminalia small; anal tube long. Female with a sclerotized ovipositor of varied structure.
Distribution. Cosmopolitan.
Key to the species in China
1. Female............................................................................................. 2
- Male.............................................................................................. 19
2. Mid tibia without setal palisade (Fig. 11D); oviscape broad and membranous at apex (Fig. 11F)..... P. formicarum (Verrall)
- Mid tibia with setal palisade of variable length.............................................................. 3
3. With 3 pairs of supra-antennal setae (Fig. 21A); abdominal sternite VI divided into two oval pieces, each bearing 3–4 setulae (Fig. 26F)........................................................................ P. hexasetalis Liu et Wang
- With 2 pairs of supra-antennal setae....................................................................... 4
4. Setal palisade extending 3/4 (0.71–0.75) length along mid tibia................................................ 5
- Setal palisade extending 1/2–2/3 (0.50–0.70) length along mid tibia............................................. 8
5. Yellow species; apical seta of palpus shorter than maximum width of palpus (Fig. 18A); abdominal sternite VI is a fine transverse strip, behind it there is two small sclerotized pieces, bearing 2 setae on it and 2–3 fine setulae outside pieces each side (Fig.25J)....................................................................... P. shennongjianus sp. nov.
- Brown species; apical seta of palpus equal to or longer than maximum width of the palpus........................... 6
6. Fore tarsomere 5 equal to tarsomere 1 (Fig. 16C); abdominal sternite VI is a transverse strip, behind it there are only 3–4 long setulae on each side, no sclerotized pieces (Fig. 25F)........................................ P. obtusatus Liu et Cai
- Fore tarsomere 5 longer than tarsomere 1 (Figs. 5C, 6C); the setulae on sternite VI very long and about 1/2 length of width of the sternite.......................................................................................... 7
7. Apical seta shorter than maximum width of palpus (Fig. 5A); abdominal sternite VI narrow in middle and broad both sides, with 4–5 long, inclinate setae (Fig. 24F)...................................................... P. inticlinatus sp. nov.
- Apical seta longer than maximum width of palpus (Fig. 6A); abdominal sternite VI is a transverse strip, with 2–3 very long setulae each side (Figs. 6F, 24H)......................................... P. setipalpatus Disney et Michailovskaya
8. Apical seta of palpus as long as adjacent setulae (Fig. 10A); setal palisade extending 1/2 (0.5–0.6) length along mid tibia (Fig. 10D); abdominal sternite VI is a transverse band, with 2 long and 2 short setulae (Fig. 25B)............................................................................................... P. rudisetosus Disney et Michailovskaya
- Apical seta of palpus clearly longer than adjacent setulae..................................................... 9
9. Apical seta of palpus shorter than maximum width of palpus (Fig. 19A)......................................... 10
- Apical seta of palpus longer than maximum width of palpus (Fig. 2A).......................................... 12
10. Abdominal sternite VI trapezoid, with 8–10 long setae at rear margin (Fig. 24D)............. P. trapeziformis Zhang et Liu
- Abdominal sternite VI narrow in middle part, with 3–4 long setae each side...................................... 11
11. Second section of wing vein costa short and with 3 dorsal setulae (Fig. 19B); abdominal sternite VI triangular each side, with 4 long setae (Fig. 26B)............................................................... P. yunnanensis sp. nov.
- Second section of wing vein costa long, with 6 dorsal setulae (Fig. 17A); abdominal sternite VI bifurcate, each of lower branch with 3 long setae (Fig. 25H)............................................................ P. linzhiensis sp. nov.
12. Abdominal sternite VI long and wide, with 4 pin-shaped setae (Fig. 1F)......................................... 13
- Abdominal sternite VI short, and thinner in middle part...................................................... 14
13. Fore tarsomere 5 longer than tarsomere 1 (Fig. 1C); all supra-antennal setae as strong as adjacent frontal setae (Fig. 1A); 4 pinshaped setae of sternite VI thicker and shorter (Figs. 1F, 24B)............................... P. quadrisetalis Liu et Cai
- Fore tarsomere 5 shorter than tarsomere 1 (Fig. 2C); upper supra-antennal setae shorter than adjacent frontal setae (Fig. 2A); 4 pin-shaped setae of sternite VI a little thinner and longer (Fig. 2F)............................ P. robustisetosus sp. nov.
14. Abdominal sternite VI divided into two pieces............................................................. 15
- Abdominal sternite VI is a transverse strip................................................................ 18
15. Abdominal sternite VI in two boot-shaped pieces (Fig. 26D); fore tarsomere 5 longer than tarsomere 1 (Fig. 20C).......................................................................................... P. calceoliformis sp. nov.
- Abdominal sternite VI not boot-shaped................................................................... 16
16. Frons with 12–16 setulae (Fig. 9A); second section of vein costa short, with 3 dorsal cilia (Fig. 9B); abdominal sternite VI divided into two oval pieces, each with 4–5 setulae (Fig. 24J); oviscape with membrane apex (Fig. 9F).................................................................................................... P. reticulatus sp. nov.
- Frons with more than 20 frontal setulae; oviscape without membrane apex....................................... 17
17. Abdominal sternite VI divided into two oval pieces, each with 3–4 setulae (Fig. 8F); oviscape with 15 irregular minute setulae (Fig. 8G)........................................................... P. botulpalpatus Disney et Michailovskaya
- Abdominal sternite VI divided into two irregular pieces, each with 2 long and 2–3 short setulae (Fig. 25D); oviscape with 12 irregular minute setulae (Fig. 14F).................................................... P. pullum Michailovskaya
18. Brown species; setal palisade 1/2 length of mid tibia (Fig. 22D); abdominal sternite VI short and wide, behind it there are 2 long setae and 0–1 minute setulae (Fig. 26H)................................................. P. tianmuensis sp. nov.
- Yellow species; setal palisade 2/3 length of mid tibia (Fig. 23D); abdominal sternite VI short and wide, with 2 long setae and 0–1 minute setulae (Fig. 26J)........................................................... P. parviflavus sp. nov.
19. Abdominal tergites with very long setulae, as long as those on anal tube (Fig. 13F); fore tarsomere 5 shorter than tarsomere 1 (Fig. 13C)............................................................... P. setosus Disney et Michailovskaya
- Abdominal tergites with very short setulae, shorter than those on anal tube....................................... 20
20. Setal palisade of mid tibia wanting (Fig. 12D)............................................. P. formicarum (Verrall)
- Setal palisade of mid tibia present....................................................................... 21
21. Setal palisade extends 1/2 length along mid tibia (Fig. 15D); second section of vein costa short, with 3 dorsal setulae(15B)................................................................................. P. pullum Michailovskaya
- Setal palisade more than 2/3 length along mid tibia (Fig. 4D); second section of vein costa long, with 4 dorsal setulae..... 22
22. Apical seta less than 2x length of maximum width of palpus (Fig. 4A); fore tarsomere 5 longer than tarsomere 1 (Fig.4C)................................................................................ P. trapeziformis Zhang et Liu
- Apical seta more than 2x length of maximum width of palpus (Fig. 7A); fore tarsomere 5 equal to tarsomere 1 (Fig. 7C)....................................................................... P. setipalpatus Disney et Michailovskaya
description: Published as part of Liu, Guang-Chun & Disney, R. Henry L., 2022, Revision of the ant-parasitizing genus Pseudacteon Coquillett (Diptera, Phoridae) from China, pp. 201-237 in Zootaxa 5138 (3) on pages 202-203, DOI: 10.11646/zootaxa.5138.3.1, http://zenodo.org/record/6559522