Amblypsilopus Bigot, 1888

Grichanov, Igor Ya., 2022, Six new species of Amblypsilopus Bigot (Diptera: Dolichopodidae: Sciapodinae) and a key to species of the Afrotropical mainland, European Journal of Taxonomy 789 (1), pp. 49-80 : 51-55

Genus Amblypsilopus Bigot, 1888

Type species

Psilopus psittacinus Loew, 1861 [as “ psitacinus Fabricius”] (original designation).

Diagnosis (based on Afrotropical species)

Arista-like stylus usually dorsal or dorsoapical on subrectangular postpedicel; wing usually hyaline, but sometimes with apical maculations; vein M 1 with elbow-shaped bend, with its basal part forming right or acute angle with vein M 1+2; vein M 2 present at least as a fold in membrane (absent in A. lenga (Curran, 1929) , but with M 1 forming strong V-shaped curvature); crossvein dm-m straight or slightly convex; legs elongate, with a few, usually weak major setae; anterior preapical seta absent on femora; male fore tarsus always modified or ornamented, often with thin elongated tarsomeres, bearing long setae or remarkable setulae; scutellum with 1 pair of strong setae, lateral pair of setae usually short, setula-like, or absent; male cercus without hook-shaped or articulated basoventral lobe (sometimes furcated from base). See also Bickel (1994, 2019) for a diagnosis of the genus.

Notes

Grichanov & Brooks (2017) provided a key to all Afrotropical genera of the subfamily Sciapodinae and mentioned that the genus Amblypsilopus is poorly defined and probably polyphyletic. Males usually have modified and ornamented podomeres (male secondary sexual characters or MSSC). Females of closely related species are generally indistinguishable morphologically (e.g., Irwin 1974; Bickel 1994; Grichanov 2021a).Therefore, the following old species described poorly from females must be considered doubtful (nomina dubia): Amblypsilopus flavicollis ( Becker, 1923) from Cameroon, A. rectangularis ( Parent, 1937) from DR Congo, A. sudanensis (Parent, 1939) from Sudan and A. tropicalis ( Parent, 1933) from DR Congo. The female of Sciapus subfascipennis Curran, 1926 from Uganda was placed in the genus Amblypsilopus by Bickel (1994), but was described with a strongly sinuate wing vein dm-m ( Curran 1926: fig. 2) and must be transferred to Chrysosoma Guérin-Méneville, 1831 (comb. nov.). The latter genus is highly diverse in Central Africa ( Grichanov 2018) with many species differing only in male characters. At present, Chrysosoma subfascipennis cannot be associated with males of other known species, being probably unrecognizable. In contrast, Chrysosoma ungulatum Parent, 1941 from Príncipe was described with an almost straight, slightly convex vein dm-m ( Parent 1941: fig. 19) and must be transferred to Amblypsilopus (comb. nov.). Males of this species have enlarged сlaws ( Parent 1941: fig. 18), similar to those in A. bipectinatus ( Parent, 1934) and A. cuthbertsoni ( Parent, 1937) . Chrysosoma centrale Becker, 1923 from Tanzania also has straight wing vein dm-m, modified fore tarsus ( Becker 1923), being very close in habitus to A. steelei Grichanov, 1996 , and is also transferred to Amblypsilopus (comb. nov.). Chrysosoma asperum Parent, 1933 , described by Parent (1934) from South Africa has the same characters, is almost identical to the South African Amblypsilopus bevisi ( Curran, 1927) and is also transferred here to Amblypsilopus (comb. nov.) and newly synonymized with A. bevisi (syn. nov.).

Key to species of Amblypsilopus Bigot, 1888 from Afrotropical mainland (males)

1. R 2+3 and R 4+5 fused at wing apex ( Amblypsilopus fasciatus species group, in part) ......................... 2

– R 2+3 and R 4+5 not fused at wing apex ................................................................................................. 6

2. Postocellar hairs numerous (at least more than a single pair); antennal postpedicel dark brown; cercus elongate with flattened area at tip .......................................................................................... 3

– Postocellar hairs comprised of one pair; antennal postpedicel yellowish; cercus small with tapered tip ...................................................................................................................................................... 4

3. Wing heavily infuscate; vein M 1 not recurved basally; apical sclerotized spot of wing tip not reaching posterior margin of wing ( Irwin 1974: fig. 15; Grichanov 2011: fig. 223); body: 7.2 mm ( South Africa) .......................................................................................... A. stuckenbergorum ( Irwin, 1974)

– Wing lightly infuscate; M 1 strongly recurved basally; apical sclerotized spot of wing tip reaching posterior margin of wing ( Irwin 1974: fig. 14); body: 7.8 mm ( South Africa) .................................. ................................................................................................................... A. retrovena ( Irwin, 1974)

4. Wing with reduced apical sclerotized spot and dense patch of thickened macrotrichia ( Irwin 1974: fig. 11); wing with two rows of hook-like setae below M 1; cercus small with elongate base ( Irwin 1974: fig. 8); body: 8.8 mm ( South Africa) ............................................ A. fasciatus ( Curran, 1924)

– Wing with well-developed apical sclerotized spot and no dense patch of thickened macrotrichia; wing without rows of hook-like setae; cercus small with short, rounded base ................................ 5

5. Arista-like stylus cylindrical at tip; upcurved portion of wing vein M 1 beyond fork M 1+2 with definite, thickened spot; dm-m with two slightly thickened areas, these thickenings not forming distinct spots ( Irwin 1974: fig. 13); body: 6.9 mm ( South Africa) ................................... A. bonniae ( Irwin, 1974)

– Arista-like stylus horizontally spatulate at tip; upcurved portion of M 1 beyond fork M 1+2 slightly swollen, with darkened area; dm-m with two definite, swollen spots ( Irwin 1974: fig. 12); body: 7.8 mm ( South Africa) ....................................................................... A. macularivena ( Irwin, 1974)

6. M 2 absent; M 1 with strong V-shaped curvature ( Parent 1937: fig. 7 as in Sciapus barbipalpis ); 4–4.5 mm ( Liberia, Sierra Leone) ................................................................ A. lenga (Curran, 1929)

– Venation normal ................................................................................................................................ 7

7. Antennal scape with 2–3 strong dorsal bristles ( Fig. 1B–C ) ( Amblypsilopus abruptus species group, in part) ............................................................................................................................................... 8

– Antennal scape glabrous ( Figs 4C , 5C ) ........................................................................................... 9

8. Fore basitarsus with posteroventral row of erect hooked hairs, as long as tarsomere width ( Fig. 1 С); hind tarsomeres 1–3 distinctly thickened ( Fig. 1D ) ( Ivory coast); body: 4.2 mm .............................. ........................................................................................................................ A. spiniscapus sp. nov.

– Fore tarsomeres 1–2 with ventral rows of microscopic white hairs along entire length ( Fig. 2D ); hind tarsus simple ( Gabon); body: 4.4 mm ............................................................. A. gabonensis sp. nov.

9. Scutellum with 15–20 long dorsal and marginal cilia in addition to pair of strong setae; antennal pedicel with very long dorsal and ventral setae ( Figs 5C , 6C ) ( Tanzania) ( Amblypsilopus mufindiensis species group) ................................................................................................................................. 10

– Scutellum with only pair of strong setae; antennal pedicel with short dorsal and ventral setae, about as long as postpedicel ( Figs 3C , 4C ) ...............................................................................................11

10. Mid tarsomeres 3–5 with only black elongate setulae ( Fig. 5E ); surstylus bilobate ( Fig. 5H ); body: 6 mm ............................................................................................................ A. mufindiensis sp. nov.

– Mid tarsomeres 3–5 with white and black elongate setulae ( Fig. 6F ); surstylus trilobate ( Fig. 6I ); body: 6.5–7 mm .................................................................................................... A. martini sp. nov.

11. Legs practically unmodified, with only fore basitarsus with ventral row of about 5 fine setae, slightly longer than diameter of segment; cercus as long as epandrium, bifurcated at apex, with unequal lobes, densely covered with long setae ( Grichanov 2021b: figs 7–8) ( Gabon) .................................. ................................................................................................................. A. ruchini Grichanov, 2021

– Fore tarsus always modified, often with fore tarsomeres 4–5 flattened, white or bearing long setae, with remarkable setae on some other podomeres; cercus various .................................................. 12

12. Fore coxa yellow; halters usually yellow; lower calypter usually with light setae ........................ 13

– Fore coxa black in at least basal forth; halters usually black-brown; lower calypter usually with black setae ( Amblypsilopus abruptus species group, in part) ......................................................... 29

13. Face broadest at middle, wider than frons (e.g., Fig. 3B ), 1.1–1.4 times as wide as high ( South Africa) ( Amblypsilopus fasciatus species group, in part) ............................................................... 14

– Face not wider than frons, gradually narrowed downward ............................................................ 15

14. Fore tibia and tarsus with erect pectination ( Fig. 3D ); mid femur with short ventral hairs; cercus with sparse long black setae along entire length, without flattened area at tip ( Fig. 3F ); body: 5 mm ...... ....................................................................................................................... A. bevisi ( Curran, 1927)

– Fore tibia and tarsus without erect pectination; mid femur with at least 3 strong ventral bristles, as long as height of femur ( Fig. 4E ); cercus with comb of regular dorsal setae except for distal fifth, with flattened area at tip covered ventrally with microscopic white hairs ( Fig. 4G ); body: 6 mm .... ................................................................................................................................. A. milleri sp. nov.

15. All coxae wholly yellow ................................................................................................................. 16

– At least mid coxa with blackish-brown spot ................................................................................... 18

16. Cercus as large as epandrium, obovoid, with small middorsal tooth bearing 2 long setae ( Grichanov 2021b: figs 5–6) ( Gabon) ................................................................... A. korotyaevi Grichanov, 2021

– Cercus narrow, short or long ........................................................................................................... 17

17. Thorax metallic green, metepimeron yellow; cercus narrow, short, densely covered with ventral hairs on distal half; body: 3.6 mm ( Grichanov 1998: fig. 22) ( DR Congo) ....................................... .............................................................................................................. A. barkalovi Grichanov, 1998

– Thorax mostly yellow; cercus filiform, nearly 3 times as long as hypopygium, with short hairs (Grichanov 2011: fig. 226); body: 7–7.5 mm ( South Africa) .......... A. rosaceus (Wiedemann, 1824)

18. Antenna mostly yellow ................................................................................................................... 19

– Antenna black ................................................................................................................................. 21

19. Fore basitarsus not enlarged; tarsomere 5 of fore tarsus enlarged, with comb of yellow setae, longer than tarsomere diameter; cercus trilobate from base ( Grichanov 1996: fig. 3); body: 9.7 mm ( DR Congo, Ethiopia, Kenya, Tanzania, Uganda) .............. A. basilewskyi ( Vanschuytbroeck, 1960)

– Fore basitarsus enlarged, with ventral pile; other tarsomeres simple; cercus bilobate or simple ... 20

20. Fore basitarsus about half as long as 4 next tarsomeres combined; cercus bilobate at apex ( Grichanov 1996: fig. 1); body: 6.2 mm ( Kenya) ........................................................ A. steelei Grichanov, 1996

– Fore basitarsus as long as 4 next tarsomeres combined; cercus not lobate, hook-shaped; body: 4.5 mm ( Tanzania) ................................................................... A. centralis Becker, 1923 comb. nov.

21. Fore tarsus with modified claws ..................................................................................................... 22

– Fore tarsus with simple claws ......................................................................................................... 24

22. Mid tibia and basitarsus with anterior and ventral ciliation of thickened setulae, as long as tibia diameter; cercus simple, with 6 subapical setae, as long as cercus ( Parent 1934: fig. 18); body: 6 mm ( Kenya) ............................................................................................... A. bipectinatus ( Parent, 1934)

– Mid tibia with simple setulae; cercus various ................................................................................. 23

23. Cercus elongate-triangular, narrow at apex, with 2 long middorsal cilia, as long as cercus ( Parent 1937: fig. 11); body: 5 mm ( Burundi, Tanzania, Zimbabwe) ............ A. cuthbertsoni ( Parent, 1937)

– Cercus subtriangular, widest at apex, with wide apical excavation ( Parent 1941: fig. 17); body 4.5 mm ( Príncipe).............................................................. A. ungulatum ( Parent, 1941) comb. nov.

24. Fore femur with ventral brush of long dense curved yellow-brown hairs; tarsomere 5 of mid tarsus white; cercus bifurcated at apex ( Grichanov 1996: fig. 5); body: 4.4 mm ( Tanzania) ....................... ............................................................................................................. A. gorodkovi Grichanov, 1996

– Fore femur without such brush; cercus various .............................................................................. 25

25. Wing with small dark apical spot ( Parent 1929: fig. 121); cercus as long as epandrium, bandlike, truncated at apex ( Parent 1929: fig. 120); body: 3 mm ( DR Congo, Senegal) ................................... ....................................................................................................................... A. nanus ( Parent, 1929)

– Wing hyaline; cercus various .......................................................................................................... 26

26. Lower calypter with white cilia; fore and mid tarsi with erect ciliation ( Fig. 7D–E ); mid tibia simple; surstylus much smaller than epandrium ......................................................................................... 27

– Lower calypter with black cilia; fore and mid tarsi without erect ciliation; mid tibia flattened dorsally and ventrally, devoid of setulae on flat sides; surstylus elongate ................................................... 28

27. Postpedicel oval, with dorsoapical arista-like stylus; mid tibia without erect ciliation; cercus simple, with small distodorsal apophysis ( Grichanov 1996: fig. 4); body: 4.3–4.6 mm ( Angola, Gabon) ..... .......................................................................................................... A. nartshukae Grichanov, 1996

– Postpedicel conoid, with apical arista-like stylus ( Fig. 7C ); mid tibia with erect ciliation; cercus with large middorsal tooth ( Fig. 7H ); body: 4.3 mm ( Tanzania) ....................... A. udzungwensis sp. nov.

28. Fore tibia flattened posterodorsally and anteroventrally, devoid of setulae on flat sides; mid tarsus with 1 st –4 th segments flattened anteriorly and posteriorly; cercus with short thick ventral process at middle ( Grichanov 1999: fig. 15); body: 4 mm ( DR Congo) ....................... A. weii Grichanov, 1999

– Fore tibia and mid tarsus simple; cercus with short narrow bifurcated ventral process at proximal third ( Grichanov 1999: fig. 14); body: 7.25 mm ( Cameroon, Ivory Coast) ...... A. knorri Grichanov, 1999

29. At least fore femur with long brown-black ventral bristles ............................................................ 30

– Fore femur with white ciliation below, sometimes with a few dorsal or preapical black hairs, or bare ................................................................................................................................................. 31

30. Fore femur with two fine black ventral setae on basal fourth, other femora bare ( Grichanov et al. 2011: fig. 3); fore and mid femur black almost entirely or brown dorsally and yellow ventrally; cercus simple, with midventral projection ( Parent 1936: fig. 9); body: 5 mm ( DR Congo) .............. .............................................................................................................. A. tenuicauda ( Parent, 1936)

– Legs entirely black; all femora with a row of brown or black setae; cercus simple, with small tubercle ( Parent 1936: fig. 1); body: 3 mm ( Burundi, DR Congo, Nigeria) ........ A. disjunctus ( Parent, 1936)

31. Cercus short, usually broad, not much longer than epandrium ...................................................... 32

– Cercus filiform, at least twice as long as epandrium ...................................................................... 35

32. All femora bare; last three tarsomeres of hind tarsus flattened; body: 2.5 mm ( DR Congo, Malawi) .................................................................................................................. A. perniger ( Becker, 1923)

– Femora with long white ventral hairs; last two tarsomeres of hind tarsus flattened; body longer than 3.5 mm ............................................................................................................................................ 33

33. Femora with ventral cilia, not longer than femur diameter; fore tibia and basitarsus with fine erect ciliation on dorsal side; cercus ( Parent 1935: fig. 28); body: 3.5 mm ( Mozambique, Zimbabwe) .... ........................................................................................................................ A. miser ( Parent, 1935)

– Femora with ventral cilia, longer than femur diameter; fore tibia and basitarsus without erect setulae ............................................................................................................................................. 34

34. Fore basitarsus 3/4 to 7/5 as long as second tarsomere and 2/5 to ⅔ as long as rest tarsomeres from second to fifth; cercus ( Grichanov 1996: fig. 8); body: 3.6–4.2 mm ( Angola, DR Congo, Ethiopia, Gabon, Guinea, Ivory Coast, Nigeria, Senegal, South Africa, Tanzania, Zambia, Zimbabwe) ......... ................................................................................................................... A. auratus ( Curran, 1924)

– Fore basitarsus 1.5–2 times as long as second tarsomere and ⅔ to 9/10 as long as tarsomeres from second to fifth; cercus ( Grichanov 1996: fig. 9); body: 3.4–3.8 mm ( Cameroon, DR Congo, Ethiopia, Kenya, Madagascar, Namibia, Nigeria, Togo, Zimbabwe) ...................... A. cilifrons ( Parent, 1937)

35. All femora with white ventral hairs on basal half, longer than femur diameter; mid femur with white hairs turning into long black hairs on apical half of posteroventral surface; apical third of fore basitarsus with ventral pad of short hooked hairs; mid tibia with two short dorsal setae; cercus with long ventral cilia; surstylus strongly curved ( Grichanov 1996: fig. 6); body: 4.5 mm ( DR Congo, Kenya, Malawi, St Helena, Tanzania, Uganda, Zimbabwe) .................. A. longifilus ( Becker, 1923)

– Femora with short ventral hairs on basal half; fore tarsus with simple setulae; cercus with short hairs; surstylus long, almost straight ( Grichanov 1996: fig. 7 as in Amblypsilopus parilis ); body: 3.5 mm ( Angola, DR Congo, Mozambique, Namibia, Nigeria, South Africa, Tanzania, Zimbabwe; Sri Lanka) .................................................................................................. A. munroi ( Curran, 1924)

( A. signatus Becker, 1923 from Malawi also keys here,

and the two names may be synonymous)

Figures

Fig. 1. Amblypsilopus spiniscapus sp. nov., holotype, ♂ (ZMUK). A. Habitus. B. Antenna. C. Fore tarsus. D. Hind tarsus. E. Hypopygium after maceration, right lateral view.

Fig. 4. Amblypsilopus milleri sp. nov., holotype, ♂ (A–G: NMSA); paratype, ♂ (H: BMSA). A. Habitus. B. Head. C. Antenna.D. Fore femur and base of fore tibia. E. Mid femur. F. Wing. G. Hypopygium, left lateral view, dry. H. Hypopygium after maceration, left lateral view.

Fig. 5. Amblypsilopus mufindiensis sp. nov., holotype, ♂ (ZMUC). A. Habitus. B. Head. C. Antenna. D. Fore femur. E. Mid tarsus. F. Wing. G. Hypopygium after maceration, left lateral view. H. Surstylus, lateral view. I. Cerci, dorsal view.

Fig. 2. Amblypsilopus gabonensis sp. nov., holotype, ♂ (ZIN). A. Habitus. B. Head. C. Antenna.D. Fore tarsomeres 2–5, lateral view. E. Hypopygium after maceration, left lateral view.

Fig. 6. Amblypsilopus martini sp. nov., holotype, ♂ (A–G: ZMUC); paratype, ♂ (H–I: ZMUC). A. Habitus. B. Head. C. Antenna.D. Wing. E. Fore femur. F. Mid tarsus. G. Mid femur. H. Hypopygium after maceration, left lateral view. I. Surstylus, lateral view.

Fig. 3. Amblypsilopus bevisi (Curran, 1927), ♂, Natal, Edendale (NMSA). A. Habitus. B. Head. C. Antenna. D. Fore tarsus. E. Wing. F. Hypopygium, left lateral view, dry. G. Hypopygium, dorsal view, dry.

Fig. 7. Amblypsilopus udzungwensis sp. nov., holotype, ♂ (ZMUC). A. Habitus. B. Head. C. Antenna. D. Foretarsus. E. Mid tarsus. F. Wing. G. Hypopygium after maceration, left lateral view. H. Surstylus, lateral view.