Igor Ya. GRICHANOV
Grichanov, I.Ya. Afrotropical species of the genus Acropsilus Mik (Diptera: Dolichopodidae)
A. olegi sp. n. from Congo (Kinshasa) and A. stekolnikovi sp. n. from Sierra Leone are described. Campsicnemus brevitalus Parent and Micromorphus perminutus Parent are transferred to the genus Acropsilus. A key to known species of Acropsilus is given.
I.Ya. Grichanov, All-Russian Institute of Plant Protection, Podbelskogo 3, St.Petersburg-Pushkin, 189620, Russia.
Key words: Diptera, Dolichopodidae, Acropsilus, Tropical Africa, key, new species, new combination.
Introduction
The representatives of the genus Acropsilus Mik are the smallest dolichopodid flies and rather rare in collections. Several species are described from various parts of the World. Two species are described from Palearctic region, one from Sumatra and one from Pacific Solomon Islands. Wingless A. borboroides Oldroid from Campbell Island has been recently separated in independent genus Apterachalcus (Bickel, 1991). The same is likely to be done for A. minutus Hollis. This species has strongly divergent wing veins R4+5 and M1+2, shortened tarsomeres 25 of fore tarsus and flattened posterior mesonotum, the features characteristic of the Nearctic genus Enlinia Aldrich. Palearctic A. niger Loew is recorded from St. Helena. A. errabundus Lamb is described from Seychelles, and A. eburneensis Couturier from Ivory Coast. In this paper A. olegi sp. n. from Congo (Kinshasa) and A. stekolnikovi sp. n. from Sierra Leone are described. Campsicnemus brevitalus Parent and Micromorphus perminutus Parent are transferred to the genus Acropsilus. Now seven species of the genus are known from the Afrotropical Region. A key to known species of Acropsilus is also given.
The genus Acropsilus is still poorly studied. It was kept within the subfamily Sympycninae (=Campsicneminae) for a long time (Dyte and Smith, 1980). Following Ulrich (1981), Bickel and Dyte (1989) regarded the genus Incertae sedis. Negrobov (1991) transferred it to the subfamily Peloropeodinae. In fact, the characters of the genus are common with those of a number of subfamilies of Dolichopodidae. The four Afrotropical species described below are quite similar to one another, having the following diagnostic attributes. Arista pubescent, inserted in apical or dorsoapical incision or excavation. Scape bare, pedicel globular, with short setulae; first flagellomere larger than pedicel, approximately as long as high, densely pubescent. Pseudotracheae geminately sclerotized. Thorax with 5 dorsocentrals gradually decreasing anteriad, acrostichals absent, posterior slope not flattened, proepisternum bare on the upper part. Wing veins R4+5 and M1+2 parallel in distal part. Posterior four femora with fine or without preapicals. Hypopygium pedunculate. 7th and 8th segments are often folded, so as hypopygium seems sessile. Hypandrium situated before the middle of ventral side of epandrium and has two positions. It is usually perpendicular to ventral side of epandrium (Figs. 1, 3 and 4) with aedeagus protruding far beyond apex of epandrium. Sometimes (in virgin males, probably), hypandrium lies by aedeagus along epandrium, and the latter conceals the base of aedeagus (Fig 2).
These features eventually place the genus in the subfamily Diaphorinae. The densely pubescent, sometimes incised at apex, first flagellomere is a character of the genus Chrysotus Meigen. The pedunculate hypopygium is unusual for the subfamily, although the argyrine genus Urodolichus Lamb has long 7th segment of hypopygium. Bilobate surstyli, well-pronounced epandrial lobi, short simple cerci and basoventral position of hypandrium are often found in genera of the subfamily Diaphorinae. The world fauna of the subfamily Diaphorinae numbers about 20 genera and subgenera united in two tribes, Argyrini and Diaphorini. Limits of the subfamily are not yet defined well, and many genera travelled to or from Diaphorinae, whereas others changed their generic status. The genus Acropsilus share features of the two tribes of the subfamily. I think it is close to the tribe Argyrini; however, the new tribe is possible for the genus.
Holotypes and paratypes of the new species are deposited in the collections of the Royal Institute for Natural Sciences (Brussels) [RINS], the Royal Museum for Central Africa (Tervuren, Belgium) [RMCA], the Hungarian Natural History Museum (Budapest) [HNHM] and Lund University (Lund, Sweden).
List of known species
Genus Acropsilus Mik
ACROPSILUS Mik, 1878:6. Type-species: Chrysotus niger Loew, 1869, by original designation [after Dyte & Smith, 1980].
brevitalus Parent, 1937: 10 (Campsicnemus), comb. n. Congo (Kinshasa), Tanzania (!).
eburneensis Couturier, 1978: 222 (Acropsilus). Ivory Coast.
errabundus Lamb, 1922: 403 (Acropsilus). Seychelles.
igori Negrobov, 1984: 1111 (Acropsilus). Tadjikistan.
minutus Hollis, 1964: 267 [?Acropsilus]. Indonesia (Sumatra).
niger Loew, 1869: 298 (Chrysotus). Hungary; St Helena, Algeria, Europe.
olegi Grichanov, sp. n. Congo (Kinshasa).
perminutus Parent, 1937: 12 (Micromorphus), comb. n. Congo (Kinshasa), Tanzania (!), Sierra Leone (!).
protractus Robinson, 1963: 830 (Acropsilus). Solomon Is.
stekolnikovi Grichanov, sp. n. Sierra Leone.
Acropsilus perminutus (Parent)
(Fig. 1)
Type material examined. Male, holotype: Congo belge, Eala, III.1936, J. Ghesquiere / R. Mus. Hist. Nat. Belg. 10482 / Micromorphus perminutus n.sp. Type, male. O. Parent / O. Parent det. 1936: Micromorphus perminutus n.sp. / Type [red label]; female paratype with same labels, dated 27.III.1936 [RINS].
Additional material. Male, Tanzania: Chemka, Tanga region / 1-18.II.1987, leg. Mahunka, Zicsi [HNHM]; male (figured), Sierra Leone, S of Freetown, close to Sussex, 13° 11'W, 8° 20'N, 30.XI.1993, loc. 4, swept at road side / Lund University Sierra Leone Expedition 1993, leg. L. Cederholm - R. Danielsson - R. Hall; 2 males, Sierra Leone, Freetown, Fourah Bay College, 13° 14'W, 8° 28'N, 24.XI.1993, loc. 7, swept at sec. forest / Lund University Sierra Leone Expedition 1993, leg. L. Cederholm - R. Danielsson - R. Hall;
Redescription of holotype. Frons black, densely brown pollinose. Ocellar tubercle with a pair of strong setae; one strong vertical seta present. Eyes practically contiguous in lower two thirds of face. Face black. Palpi and proboscis very short, brown, palpus with a small bristle. Antenna black; scape and pedicel short; first flagellomere slightly longer than high at base, with narrow incised apex, densely pubescent; incision 1/4 as deep as length of first flagellomere. Arista inserted in apical incision, 3 times as long as antennomeres, distinctly pubescent.
Mesonotum metallic black, brown pollinose; pleura and scutellum black, grey pollinose; scutellum brown along posterior margin. 5 dorsocentral setae decreasing in size anteriorly, with small hair in front of the first one; acrostichals absent; one humeral, two notopleural setae; several propleural hairs present. Scutellum with two strong bristles.
Legs mostly yellow, middle and hind coxae dark at base, apical segments of tarsi darkened. Fore and middle coxae with short yellow-brown hairs, middle and hind coxae with one black external bristle. Fore femur and tibia bare. Fore tarsus simple. Length ratio of fore femur to tibia to tarsus (segments from first to fifth), 43 : 48 : 20 : 12 : 10 : 7 : 6. Middle femora bare, with short subapical hairs. Middle tibia simple, with 1 anterodorsal, 1 posterodorsal at basal 1/4, 1 anterodorsal at distal 1/3, 2 3 apical setae. Middle tarsus simple. Length ratio of middle tibia to tarsus (segments from first to fifth), 74 : 21 : 16 : 12 : 7 : 10. Hind femur with several short subapical hairs. Hind tibia with one fine dorsal seta at base and at apex. Hind basitarsus short, with short apicodorsal scale and several ventral setulae nearly as long as diameter of tarsomere. Length ratio of hind tibia to tarsus (segments from first to fifth), 68 : 10 : 20 : 12 : 8 : 8.
Wings hyaline, veins brown. R1 short, reaching to first third of wing. R2+3 straight. R4+5 and M1+2 straight and parallel. Ratio of part of costa between R2+3 and R4+5 to this between R4+5 and M1+2, 25 : 11. Ratio of apical to basal part of M1+2, 7 : 6. Ratio of m-cu to apical part of CuA1, 8 : 25; m-cu straight. Anal lobe absent. Anal angle obtuse. Lower calypter brown, with black cilia. Halter yellow-brown.
Abdomen 6-segmented, black, with dark hairs, pressed from lateral sides. Hypopygium brown, pedunculate, extending under abdomen; 7th segment approximately as long as epandrium. Cercus yellow, elongate, narrowed apicad, densely pubescent. Surstylus half as long as cercus.
Female paratype with head, middle leg, fore and hind tarsus broken. Similar to male except lacking male secondary sexual characters.
Length (mm): body 0.9, antenna 0.4, wing-length 1.0, wing-width 0.4, hypopygium 0.25.
Distribution: Congo (Kinshasa), Tanzania (!), Sierra Leone (!).
Diagnosis and variability. The smallest species in the genus. Frons sometimes with violet tinge. Antenna black or brown. Mesonotum black or brown, sometimes with greenish reflection. Pleura entirely black-brown or yellowish above coxae. Middle and hind coxae entirely yellow or brownish at base. Fore basitarsus 2/5 as long as tibia; fore tarsus 1.2 times longer than tibia. Middle and hind tibiae slightly longer than respective femora. Lower calypter brown or yellowish-brown. Halter yellow or yellowish-brown. Hypopygium brown or yellow. Epandrium distinctly longer than high. Three ventral epandrial setae: the first one short, positioned at base of hypandrium; the second is long and strong, situated just before epandrial lobe, neighbouring to the third seta that is half as long as the second. Hypandrium arising just before middle of ventral side of epandrium, straight, slightly broadened apicad, distinctly shorter than height of epandrium, with apical furrow. Aedeagus arising at base of hypandrium, trilobate, with lateral lobi gradually widened apicad and rounded at apex; medial lobe thin, curved ventrad at apex, tapering at apex, 5/6 as long as lateral lobi. Apicoventral epandrial lobe subtriangular, broad, narrowed at apex, with 2 apical and 2 subapical setae; one strong apicoventral pedunculate epandrial seta on short pedicel positioned at base of epandrial lobe internally. Surstyli bilobate, thin, slightly curved, with rounded apex; ventral lobe half as long as cercus, with one strong apical seta; dorsal lobe distinctly shorter than ventral lobe, with apical and subapical short setae. A small rounded, weakly sclerotized, unpaired epandrial process visible between surstyli and cerci. Additional broad epandrial lobe with 5 pedunculate setae positioned at base of each cercus. Cercus elongate, 4 times as long as wide at base, narrowed apicad, densely pubescent; ventral setae sparse, half as long as cercus and twice longer than dorsal hairs.
Acropsilus brevitalus (Parent)
(Fig. 2)
Type material examined. Male, holotype: Congo belge, Eala, III.1936, J. Ghesquiere / R. Mus. Hist. Nat. Belg. 10482 / Campsicnemus brevitalus n.sp. Type, male. O. Parent / O. Parent det. 1936: Campsicnemus brevitalus n.sp. / Type [red label] / cf. Bull. Mus. Hist. Nat. Belg. XIII-18 (1937), p. 10, pt. 3-4, fig. 26-27 [RINS].
Additional material. 2 males, Congo Belge, P.N.A., 7-15.VII.1955, P. Vanschuytbroeck, 13274-309 / Mont Hoyo, 1280 m, sur plantes basses [RINS]; 11 males, Congo Belg.: P.N.G., Mission H. De Saeger, I/o/2 [II/gd/8; II/hd/8; II/dd/8; II/gd/7"; II/gd/10; II/gc/8; II/le/8], 2.XI.1950 [20.IV.1951, 3.VIII.1951, 6.IX.1951, 20.IX.1951, 24.IX.1951, 10.VII.1952, 9.IX.1952], Rec. H. De Saeger, 923, 1947, 2195, 2383, 2448, 2483, 3765, 4040, 4042 [RMCA]; male, Tanzania: Amani, Tanga region / 1-18.II.1987, leg. Mahunka, Zicsi [HNHM]; male, Tanzania: Kwamgumi, Tanga region, 4.II.1987, leg. Mahunka [HNHM].
Redescription of holotype [abdomen, middle and hind legs broken]. Frons with one strong vertical seta. Eyes nearly contiguous. Face grey pollinose, narrowest in the middle, slightly widened at clypeus. Short black postocular setae present. Palpus small, black, with black seta. Antenna black; scape and pedicel short; first flagellomere as long as high at base. Arista inserted in subapical incision, distinctly pubescent.
Thorax black. 5 dorsocentral setae decreasing in size anteriorly; acrostichals absent. Scutellum with two strong bristles and two lateral hairs.
Legs including coxae yellow, apical segments of fore tarsus gradually darkened. Fore coxa with short brown hairs and several long fine cilia at apex. Fore femur and tibia bare. Fore tarsus simple; 5th tarsomere with several elongate dorsal hairs. Length ratio of fore femur to tibia to tarsus (segments from first to fifth), 82 : 76 : 51 : 30 : 20 : 13 : 12.
Wings hyaline, veins brown. Ratio of part of costa between R2+3 and R4+5 to this between R4+5 and M1+2, 35 : 24. Transverse vein m-cu 1/3 or 2/5 as long as apical part of CuA1. Lower calypter dark, with black cilia. Halter black-brown.
Length (mm): head and thorax combined 1.0, wing 1.4.
Distribution: Congo (Kinshasa), Tanzania (!).
Diagnosis and variability. Frons black, with violet tinge. Middle and hind coxae entirely yellow or brownish at base. Fore basitarsus from 1/2 to 2/3 as long as tibia; fore tarsus 1.51.7 times longer than tibia. Middle and hind femora with small anterior subapical seta. Middle and hind tibiae slightly longer than respective femora. Middle basitarsus 2/5 as long as tibia. Hind basitarsus half as long as next segment. Ratio of part of costa between R2+3 and R4+5 to this between R4+5 and M1+2, from 1.5 to 1.8. Halter yellow-brown or black-brown. Hypopygium brown, pedunculate, extending under abdomen. Epandrium distinctly longer than high. Three ventral epandrial setae: the first one short, positioned beyond the middle of epandrium; the second is long and strong, situated just before epandrial lobe, neighbouring to the very small third seta. Hypandrium arising at proximal third of ventral side of epandrium, straight, slightly broadened apicad, distinctly shorter than height of epandrium, with apical furrow. Aedeagus arising at base of hypandrium, trilobate, with lateral lobi gradually widened apicad and rounded at apex; medial lobe thin, curved ventrad at apex, tapering at apex, nearly as long as lateral lobi. Apicoventral epandrial lobe narrow, slightly curved, with 1 apical and 1 subapical setae; one short apicoventral pedunculate epandrial seta positioned at base of epandrial lobe. Surstyli bilobate, with lobi of equal length, 1/3 as long as cercus, thin, slightly curved; ventral lobe narrowed at apex, with one strong apical seta; dorsal lobe rounded at apex, with apical and subapical short setae. A small, weakly sclerotized, glossate, unpaired epandrial process visible between surstyli and cerci. Additional broad epandrial lobe with 4 pedunculate setae positioned at base of each cercus. Cercus elongate, 4 times as long as wide in middle, narrowed at apex, densely pubescent; ventral setae sparse, half as long as cercus and much longer than dorsal hairs. Length (mm): body 1.21.5, antenna 0.7, wing-length 1.4, wing-width 0.5, postabdomen 0.4.
Remark. A. eburneensis Couturier is possible synonym to A. brevitalus Parent.
Acropsilus stekolnikovi Grichanov, sp. n.
(Fig. 3)
Holotype. Male, Sierra Leone, S of Freetown, close to Sussex, 13° 11'W, 8° 20'N, 30.XI.1993, loc. 4, swept at road side / Lund University Sierra Leone Expedition 1993, leg. L. Cederholm - R. Danielsson - R. Hall.
Description. Male. Frons shining black-violet. Ocellar tubercle with a pair of strong setae; one strong vertical seta present, as a linear continuation of postocular row of short black setae. Occiput flat. Epistome concave. Face black, grey pollinose, greatly narrowing in lower half; ratio of its width below antennae to height to clypeus width, 8 : 12 : 2. Palpi and proboscis very short, black, palpus with a small bristle. Antenna black; scape and pedicel short; first flagellomere slightly longer than high at base, with incised apex, densely pubescent, with apical hairs as long as this segment. Arista inserted in apical incision, 3 times as long as antennomeres, distinctly pubescent.
Thorax metallic black with greenish reflection, weakly pollinose. Mesonotum convex. Five dorsocentral setae decreasing in size anteriorly; acrostichals absent; at least one fine propleural seta present. Scutellum with two strong bristles.
Legs mostly yellow, middle and hind coxae dark at base, apical segments of tarsi darkened. Fore and middle coxae with short yellow-brown hairs, middle and hind coxae with one black external seta. Fore femur and tibia bare. Fore tarsus simple. Length ratio of fore coxa to femur to tibia to tarsus (segments from first to fifth), 17 : 25 : 24 : 11 : 6 : 5 : 5 : 4. Middle femora bare, with short subapical hairs. Middle tibia simple, with 1 anterodorsal, 1 posterodorsal at basal 1/4, 1 anterodorsal at distal 1/3, 34 apical setae. Middle tarsus simple. Length ratio of middle coxa to femur to tibia to tarsus (segments from first to fifth), 12 : 32 : 35 : 13 : 9 : 7 : 5 : 5. Hind femur with several short subapical hairs. Hind tibia with one fine short dorsal seta at base and at apex. Hind basitarsus short, with short apicodorsal scale and several ventral setulae nearly as long as diameter of tarsomere. Length ratio of hind coxa to femur to tibia to tarsus (segments from first to fifth), 9 : 32 : 40 : 5 : 12 : 8 : 6 : 5.
Wings evenly greyish, veins brown. R1 short, reaching to first third of wing. R2+3 straight. R4+5 and M1+2 straight and parallel. Ratio of part of costa between R2+3 and R4+5 to this between R4+5 and M1+2, 14 : 7. Ratio of apical to basal part of M1+2, 38 : 30. Ratio of m-cu to maximal distance between R4+5 and M1+2 to apical part of CuA1, 5 : 8 : 11; m-cu straight. Anal vein absent. Anal angle obtuse. Lower calypter brown, with black cilia. Halter yellow-brown.
Abdomen 6-segmented, black, with dark hairs, pressed from lateral sides. Hypopygium brown, pedunculate, extending under abdomen; Epandrium distinctly longer than high, with wide and shallow midventral excavation. Three ventral epandrial setae: the first one short, positioned at base of hypandrium; the second is long and strong, situated at distal third, neighbouring to the fine third seta positioned on small ventral eminence. Hypandrium arising at proximal third of ventral side of epandrium, straight, narrowed at base, distinctly longer than height of epandrium, with apical furrow. Aedeagus arising at base of hypandrium, trilobate, with lateral lobi flat, gradually widened apicad and rounded at apex (lateral view); medial lobe at apex straight, tapering and incised, at base nearly as wide as lateral one, approximately half as long as lateral lobi. Apicoventral epandrial lobe narrow, slightly curved, with 2 apical setae of different length; one short apicoventral pedunculate epandrial seta on long thin pedicel positioned at base of epandrial lobe. Surstyli bilobate, with lobi of equal length, 4/5 as long as cercus, very thin; ventral lobe strongly curved, narrowed at apex, with one strong apical seta; dorsal lobe stick-shaped, with apical short seta. A large globular, weakly sclerotized, unpaired epandrial process visible between surstyli. Additional narrow epandrial lobe with 2 pedunculate setae positioned at base of each cercus. Cercus yellow, elongate-oval, nearly 3 times as long as wide in middle, rounded at apex, densely pubescent; apical and ventral setae dense, half as long as cercus and 3 times longer than dorsal hairs.
Female unknown.
Length (mm): body 1.1, antenna 0.6, wing-length 1.2, wing-width 0.4, postabdomen 0.4.
Distribution: Sierra Leone.
Etymology. The species is named for the Russian entomologist, Prof. A.A. Stekolnikov.
Diagnosis. The new species is related to A. perminutus, differing in hypopygium morphology mainly. Fore basitarsus 0.45 times as long as tibia; fore tarsus 1.3 times longer than tibia. Middle and hind tibiae slightly longer than respective femora. Hind basitarsus nearly 1/3 as long as next segment. Epandrium distinctly longer than high, with wide and shallow midventral excavation. Hypandrium distinctly longer than height of epandrium. Aedeagus with lateral lobi flat, gradually widened apicad and rounded at apex (lateral view); medial lobe at apex straight, tapering and incised, at base nearly as wide as lateral one, approximately half as long as lateral lobi. Apicoventral epandrial lobe narrow, with 2 apical setae of different length; one short apicoventral pedunculate epandrial seta on long thin pedicel. Surstyli with lobi of equal length, 4/5 as long as cercus, very thin. A large globular epandrial process visible between surstyli. Cercus elongate-oval, nearly 3 times as long as wide in middle, approximately half as long as hypandrium or epandrium.
Acropsilus olegi Grichanov, sp. n.
(Fig. 4)
Holotype. Male, Congo Belg.: P.N.G., Mission H. De Saeger, Mabanga, 29.IX.1952, H. De Saeger, 4103 [RMCA].
Paratypes. 4 males, Congo Belge, P.N.G., Miss. H. De Saeger, II/dd/8, II/fd/17, 6.XI.1951, 9.VII.1952, Rec. H. De Saeger, 2383, 3763 [RMCA]; 8 males, Congo Belge, P.N.A., 7-15.VII.1955, P. Vanschuytbroeck, 13274-309 / Mont Hoyo, 1280 m, sur plantes basses [RINS].
Description. Male. Similar to A. stekolnikovi sp.n. in almost all respects except as noted. Palpi and proboscis brown. Antenna dark-brown; first flagellomere with apical hairs half as long as this segment. Thorax metallic black-brown. Length ratio of fore coxa to femur to tibia to tarsus (segments from first to fifth), 15 : 23 : 21 : 11 : 5 : 5 : 4 : 4. Same ratio for middle leg, 12 : 26 : 32 : 11 : 8 : 6 : 4 : 4. Same ratio for hind leg, 8 : 30 : 34 : 5 : 11 : 7 : 5 : 4. Ratio of part of costa between R2+3 and R4+5 to this between R4+5 and M1+2, 15 : 7. Ratio of m-cu to maximal distance between R4+5 and M1+2 to apical part of CuA1, 5 : 6 : 13.
Abdomen black-brown, with dark hairs, pressed from lateral sides. Hypopygium brown, pedunculate, extending under abdomen; Epandrium slightly longer than high, with sinuate ventral side. Three ventral epandrial setae: the first one short, positioned at base of aedeagus; the second is long and strong, situated at distal third, neighbouring to the short third seta positioned on small ventral tubercle. Hypandrium arising at proximal third of ventral side of epandrium, straight, narrowed at base and extreme apex, as long as height of epandrium, with apical furrow. Aedeagus arising at base of hypandrium, trilobate, with lateral lobi flat, slightly widened apicad and tapering at extreme apex (lateral view); medial lobe broad, wider than lateral one, with long acicular process reaching 4/5 the length of lateral lobe; basal broad part of medial lobe approximately half as long as lateral lobi. Apicoventral epandrial lobe narrow, short, half as long as surstylus, with 2 apical setae of equal length; one short apicoventral pedunculate epandrial seta on short thin pedicel positioned at base of epandrial lobe. Surstylus bilobate, with lobi of equal length, 2/3 as long as cercus; ventral lobe wider than dorsal one, curved, narrowed at apex, with one strong apical and one subapical setae; dorsal lobe stick-shaped, with apical short seta. A small conoid, weakly sclerotized, unpaired epandrial process visible between surstyli and cerci. Additional short epandrial lobe with 4 pedunculate setae positioned at base of each cercus. Cercus yellow, elongate-oval, 3 times as long as wide in middle, rounded at apex, densely pubescent; apical and ventral setae dense, nearly half as long as cercus and twice longer than dorsal hairs.
Female unknown.
Length (mm): body 1.2, antenna 0.6, wing-length 1.2, wing-width 0.4, postabdomen 0.4.
Distribution: Congo (Kinshasa).
Etymology. The species is named for the Russian entomologist, Prof. Oleg P. Negrobov.
Diagnosis and variability. The new species is closely related to A.
stekolnikovi sp.n., differing in hypopygium morphology mainly. Fore basitarsus
half as long as tibia; fore tarsus 1.4 times longer than tibia. Middle
and hind tibiae slightly longer than respective femora. Hind basitarsus
approximately half as long as next segment. Epandrium only slightly longer
than high, with sinuate ventral side. Hypandrium as long as height of epandrium.
Aedeagus with lateral lobi slightly widened apicad and tapering at extreme
apex (lateral view); medial lobe broad, wider than lateral one, with long
acicular process reaching 4/5 the length of lateral lobe; basal broad part
of medial lobe approximately half as long as lateral lobi. Three paratypes
from Parc National Garamba have lateral lobi of aedeagus with pointed apex,
twice wider than figured, and medial lobe with very short acicular apical
process. Apicoventral epandrial lobe narrow, short, half as long as surstylus,
with 2 apical setae of equal length; one short apicoventral pedunculate
epandrial seta on short thin pedicel. Surstyli with lobi of equal length,
2/3 as long as cercus; ventral lobe wider than dorsal one, curved, narrowed
at apex. A small conoid epandrial process visible between surstyli and
cerci. Cercus elongate-oval, 3 times as long as wide in middle, nearly
as long as hypandrium or epandrium.
Key to known species of Acropsilus Mik (males)
1. Femora black-brown ................... 2
Femora mostly yellow ................... 3
2. Tibia dark; arista subapical; size about 1.75 mm ................... A. niger
Tibia yellow; arista basodorsal; 1.41.5 mm ................... A. igori
3. Legs extremely long: fore tarsus twice longer than tibia, middle and hind tibiae 1.5 times longer than respective femora; body 2.3, wing 2.0, legs 3.04.5 mm ................... A. errabundus
Legs much shorter: fore tarsus no more than 1.7 times longer than tibia; middle and usually hind tibia only slightly longer than respective femora; smaller species ................... 4
4. Male face with distinct setae on clypeus; antenna yellow or yellowish-brown................... 5
Male face without distinct setae on clypeus; antenna black or brown ................... 6
5. Wing veins R4+5 and M1+2 distinctly divergent; tarsomeres 25 of fore tarsus shortened, as long as basitarsus; 1.52.0 mm ................... A. minutus
Wing veins R4+5 and M1+2 parallel in apical part; fore tarsomeres 25 combined 1.5 times longer than basitarsus; 1.0 mm ................... A. protractus
6. Cercus narrow, 4 times longer than wide, as long as or longer than height of epandrium; surstylus no more than half as long as cercus ................... 7
Cercus broader, 3 times longer than wide, distinctly shorter than height of epandrium; surstylus at least 2/3 as long as cercus ................... 9
7. Epandrial lobe broad, subtriangular, much wider than lobi of surstylus, with 4 setae at apex; body 0.80.9 mm ................... A. perminutus
Epandrial lobe stick-shaped, narrower than lobi of surstylus, with 2 setae at apex; larger species ................... 8
8. Size about 1.75 mm; West Africa ................... A. eburneensis
1.21.5 mm; Central Africa ................... A. brevitalus
9. Lateral lobi of aedeagus rounded at apex; cercus approximately half as long as hypandrium or epandrium; 1.1 mm ................... A. stekolnikovi
Lateral lobi of aedeagus curved dorsad and tapering at apex; cercus
nearly as long as hypandrium or epandrium; 1.2 mm ................... A.
olegi
Acknowledgements
I express sincere gratitude to Dr. Patrick Grootaert, Dr. Marc De Meyer, Dr. Laslo Papp and Dr. Roy Danielsson for their kindness in furnishing an opportunity to study the collections of the Royal Institute for Natural Sciences (Brussels), the Royal Museum for Central Africa (Tervuren, Belgium), the Hungarian Natural History Museum (Budapest) and Lund University (Sweden).
References
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Remarks under figures
Figs 14. Acropsilus spp. Hypopygium, lateral view (ventral setae on cercus are not figured).
Fig. 1. A. perminutus (Parent)
Fig. 2. A. brevitalus (Parent)
Fig. 3. A. stekolnikovi sp. n.
Fig. 4. A. olegi sp. n.