Bengalia africanoides, Rognes, 2012

Rognes, Knut, 2012, 3553, Zootaxa 3553, pp. 1-79 : 58-60

8. Bengalia africanoides sp. nov.

Figs. 174–192.

Etymology. The specific name “ africanoides ” is derived from the stem of “ africana ” with the addition of the Latin suffix “ -oides ” (meaning like, resembling, in the form of) referring to my immediate (and erroneous) belief that it was the male counterpart of B. africana , based on the female holotype, and the similarity of the two species with respect to the presence of almost only black setulae on the anepimeron.

Diagnosis. Male. Length: 11mm (n=1). Frons at vertex / head width ratio: 0.28 (n=1). The species is recognisable in the male sex by the unique shape and the small size of the ST5 flap in combination with the presence of only 3 post dc, a unique feature among Bengalia species (cf. Zumpt 1956, Lehrer 2005), the absence of a distal finger in the distiphallus and the absence of a projecting process on the upper bacilliform sclerite.

Anepimeron with mostly black setulae. Fore tibia without strong ventral setae in proximal half; a pv fringe present on distal half. Mid tibia with an av, v, and pv fringe on more than distal half. Hind tibia with an av, v and pv fringe of long and densely set setae on distal four fifths. No spine-like setae on the fore or other femora.

T4 with medial marginal setae widely separated. T5 with one strong and one weak discal seta ( Fig. 190).

The ST5 flap broader than long with two lateral convexities with a slight medial depression between them; densely clothed with microtrichiae over entire surface.

Cerci bent slightly backwards in distal half. Cercal prongs not very strong and widely separated from each other. Surstylus broad, outer edge semicircular, the inner edge weakly concave. Bacilliform sclerite without projecting process.

Distiphallus with rather low dorsolateral wings and short bifurcate weakly sclerotised antlers. No distal finger present. In dorsal view upper lip distally slightly convex, strongly concave on underside seen from front. Lateral finger relatively thick, curved, projecting outwards and backwards well beyond outer edge of external hypophallic lobe in dorsal or ventral view. External hypophallic lobe slightly folded distally. Internal hypophallic lobes parallel. Ventral finger rounded in lateral view.

Female. Unknown, but if the number of 3 post dc in the male is a constant property, the female should be easily recognisable on that feature.

Description. Measurements. See Diagnosis above.

Male. Head. Yellow ground colour, with golden microtomentum. Anterior two thirds of frontal vitta honeyyellow without much microtomentum. Slightly darkened areas according to angle of light on each side of lunula, and on each side of vertex around and behind each reclinate prevertical seta. 6–7 frontal setae on each side. Frontoorbital plate narrow, with a single row of black setulae, without proclinate orbital setae. The posteriormost setula on left side strongest, and almost half as long as the posteriormost frontal seta. Lunula bare. Frontal vitta with numerous short, very slender black setulae. Frons slightly constricted at level of lunula, giving it the appearance of narrowing somewhat from vertex to lunula (possibly due to the slightly teneral state of the specimen). Parafacial narrow, with a single row of small black setulae. Vibrissal corner with 6 very short setae lateral to base of vibrissa. Vibrissa situated a little above the lower facial margin in profile view, latter not projecting. Occiput and gena with long pale setulae, with a few interspersed black setulae on genal dilation. Palpus with three short apical setae, three long seta below on distal half. A group of three very long setae on a sclerite near the base of the palpus. First flagellomere dark on outside, yellow medially, except along fore edge.

Thorax. Brownish yellow dorsally, with two darker vittae just inside of the row of dorsocentral setae beginning far forward on the prescutum and ending slightly in front of the second post dc. Another dark vitta, much shorter, is present more laterally. It ends posteriorly midway between the post ia seta and the second post dc seta and ends anteriorly at the level of the first post dc. Ground setulae black all over. 0 + 1 acr (just in front of scutellum, deep down in the hole made by the pin); 1 + 3 dc (on both sides of thorax; the prst dc close to suture; the three post dc placed at regular intervals, becoming stronger posteriorly, foremost post dc stronger than in species with 4 post dc); 0 + 1 ia; 3 sa (hindmost very weak); 2 pa; 1 prst; 1 ph (the inner); 2 h; 2 npl; 1 strong seta (dc?) very far forward on prescutum just inside the anteromedial corner of the humeral callus; 3 scutellar marginals, a weak discal pair close to apical scutellars. Pleura yellow with irregular darkening according to angle of view. Numerous black setulae around bases of the single proepisternal and single proepimeral setae. Proepisternal depression (prosternum) bare. Anterior and posterior thoracic spiracles yellow. 5–6 strong marginal anepisternal setae accompanied by densely set and rather long black ground setulae both between them and behind them. Remainder of anepisternum covered with black ground setulae in posterior and upper part. Anepimeron with almost all ground setulae on posterior half black, a few of them invading anterior half of anepimeron. Katepisternum with black ground vestiture all over; 1+1 kepst. Meron with 5–6 strong black setae with 1–2 shorter ones between. Extreme lower part of meron and all of metakatepisternum with pale ground setulae. No coxopleural streak. Anatergite with a group of black setulae below lower calypter. Katatergite bare. Postalar wall with black setulae. Prosternum with pale ground setulae.

Wing. Tegula, basicosta and subcostal sclerite yellow; wing veins all yellow; costa hairy below to slightly beyond junction with R 1 only, thus second costal sector setulose below, but most of the remainder of the costa bare below; R 4+5 setulose on the upper side of wing from node halfway to r-m crossvein. Lower calypter with inner margin converging with long axis of fly, more than twice as long as upper. Both calypters with white fringe hairs, except at the junction of upper and lower calypter where they are brownish. Halter yellow.

Legs. All parts yellow, except distal tarsomere on mid leg, and two distal tarsomeres on hind leg which are definitely brownish. Fore tibia without strong ventral setae in proximal half; with three weak ad setae, lowermost about as long as the diameter of tibia, the two upper ones much shorter; 1 pv seta at about lower 2/5, lost on left side (socket visible); distinct fringe on lower half of fore tibia, consisting of long slender setae, longest longer than the pv seta; ad, d, and pv preapical setae in increasing size. Fore femur without pv spine-like setae. Mid tibia with 1 ad, 2 p and 1 long and slender pv seta at same level as lowermost p seta; an av, v, and pv fringe on more than distal half. Mid femur with 2 a at middle; no a preapicals; a short pv preapical ctenidium consisting of 5–6 short setae; 5–6 long pv setae at middle. Hind tibia with 1 ad (lost on left side) at middle of tibia; no av seta at lower fifth among the fringe setae (likely to be an aberration, sometimes encountered also among other species); no pd setae; an av, v and pv fringe of very long and densely set setae on distal four fifths. Hind femur with an ad row of 5–6 strong setae; an av row of 10–12 very weak and slender setae.

Abdomen. Tergites and sternites yellow, with greyish-white microtomentum in shifting pattern; marginal dark bands on all segments, about one quarter of tergite length; TST7+8 and epandrium brown. T1+2 with a bundle of 5–6 discal marginals; T3 with 4–5 weak lateral marginals; T4 with 3–4 lateral marginals on each side and a pair of widely separate medial marginals ( Fig. 190). T5 with one strong and one weak median discal seta ( Fig. 190). ST1–5 with pale ground vestiture with some black setulae especially along margins. ST5 flap yellowish-white under the stereomicroscope.

Male genitalia. See under Diagnosis, above.

Female. Unknown, but if the number of 3 post dc in the male is constant, the female should be recognisable by that feature.

Discussion. I first thought that the holotype of B. africanoides , since not referable to any known Bengalia male, was the male of B. africana Malloch , known only from the holotype female from Kenya. With that nominal species it shared the presence of only black setulae on the anepimeron. However, an anepimeron with only or almost only black setulae is also present in B. roubaudi and B. depressa ; so, for the sake of this argument, B. africana might equally well be the unknown female of one of these species. The presence of 3 post dc is interesting and important. All other Bengalia , as far as I am aware, have 4 post dc arranged as two smaller ones in front, the third much stronger, the prescutellar dc very strong. In B. africanoides the three post dc are placed at regular intervals indicating that this is their normal distribution, and not positioned as if one of the usual 4 post dc in Bengalia has failed to develop. In addition, the first post dc is stronger than the first usually is when 4 post dc are present. This feature, together with the morphology of the distiphallus, strongly suggest that the holotype represents a new species, and rule out the possibility that it is the male counterpart of the female holotype of B. africana . Note that I have argued for separate reasons that B. africana is a junior synonym of B. depressa (see above under that species).

Biology. Unknown.

Distribution. * Central African Republic.

Material examined. Type material. Holotype male, in MNHN, labelled (1) Forêt pres savane / REP. CENTRAFRIC. / LA MABOKE / 27.VIII.1970 / L. Matile rec. [printed on blue label, line 1 is handwritten, line 4 handwritten except the digits 19]; (2) HOLOTYPE (m) / Bengalia / africanoides n. sp. / K. Rognes des. 2012 [printed on red label] ( Fig. 181). Dissected by KR. Abdominal tergites T4 and T5 glued to card on pin, ST4–5 and genitalia in glycerol in vial on pin between labels. The specimen is somewhat teneral, which is revealed by somewhat flattened femora, flattened abdomen with very fragile, not fully sclerotised abdominal tergites. For dissection I tried as usual to break the junction between the anterior end of the abdomen and the thorax by pressing the tip of a fine forceps gently against the hind part of the abdomen from below, but during the attempt the abdomen broke instead at the level of segment 3, which was partly destroyed in the process. The abdominal segments 1 and 2 are in situ. The anterior portion of the hypandrium and the distal part of the ejaculatory sclerite are not fully developed, but the other genital parts are well formed, although not heavily sclerotised.