Bengalia Robineau-Desvoidy

Rognes, Knut, 2012, 3553, Zootaxa 3553, pp. 1-79: 8-10

publication ID

17C95920-B910-4149-8516-AA6A83373244

publication LSID

lsid:zoobank.org:pub:17C95920-B910-4149-8516-AA6A83373244

persistent identifier

http://treatment.plazi.org/id/0390BE19-FFF5-3033-91DF-FF602DC4CC2C

treatment provided by

Felipe

scientific name

Bengalia Robineau-Desvoidy
status

 

Key to males of Afrotropical Bengalia Robineau-Desvoidy  

I recommend study of the genitalia before attempting identification of any Afrotropical Bengalia   specimens. At the very least the male genitalia should be examined before assigning an Afrotropical specimen to the Bengalia spinifemorata   group. One species, Bengalia wyatti   , with very closely set T4 marginals, pv spinous setae on fore femur, only (or almost) yellow setulae on anepimeron and no fringe on hind tibia, thus mimicking the condition in most members of the spinifemorata   species-group, belongs to the peuhi   species-group.

Many species can be identified by the shape of the ST5 flap, but great caution should be exercised when attempting this. First, because this structure may be quite variable in some species. An outstanding example is the ST5 flap of Bengalia tibiaria   (cf. Figs. 163–165); I have seen specimens with an even smaller nick in the hind edge than shown in Fig. 165. Second, it is often quite difficult to appreciate correctly its precise shape in dried specimens, because the distal margins may be transparent and without microtrichiae.

The Oriental species Bengalia unicolor Séguy   has been incorporated into the key to distinguish it from the similar Afrotropical species B. minor Malloch   and B. peuhi Villeneuve   with regard to the morphology of the distiphallus. There is also an entry in the key to the other Oriental species of the B. peuhi   species-group.

All Afrotropical Bengalia species   have a pair of strong discal setae on T5. Very rarely T5 lacks discal setae. This is the usual condition in Bengalia aliena Malloch. I   have seen only two other instances of this, which I interpret as individual aberrations: a male of B. peuhi   and a female of B. depressa Walker. The   latter specimen is the holotype of a separate nominal species ( Bengalia africana Malloch   , a junior synonym of B. depressa   ).

1 Hind tibia with 1–2 pd setae, one at about middle, the other in upper part; anepimeron with yellow setulae only; hind tibia with a dense fringe in at least lower two thirds, on av, a and pv surfaces............................................... 2

- Hind tibia without pd setae............................................................................. 4

2 ST5 flap a short, transverse, rectangular piece, half as long as wide, with an almost straight hind edge; fore tibia without or with short ventral spine-like setae in proximal half, their length at most about half the width of the tibia ( Figs. 1–4); lunula with or without setulae; epandrium yellow; basitarsus of hind leg without long av setae longer than diameter of basitarsus; T5 sometimes with reduced or enlarged number of discal setae; distal part of external hypophallic lobes projecting laterally outside of proximal part of that lobe, as seen in ventral view of distiphallus; lateral finger small, not projecting beyond outer / lateral edge of distal part of external hypophallic lobe as seen in ventral view; dorsolateral wings as seen from front of aedeagus, forming an angle of slightly less than a right angle, the outermost part of the dorsolateral wings rather horizontal, transparent and visible in dorsal view of the aedeagus, distal edges widest apart about at level of distalmost part of external hypophallic lobe; antler tip with 2–3 small tines close together................................................ Bengalia minor Malloch  

- ST5 flap at least as long as broad; fore tibia usually with prominent ventral spine-like setae in proximal half ( Rognes 2009: 64 fig. 183; Fig. 20); lunula bare or setose; epandrium yellow or black; basitarsus of hind leg with long av setae, longer than diameter of basitarsus; dorsolateral wings of distiphallus not visible in dorsal or ventral view.............................. 3

3 ST5 flap with a posterior edge showing a slight concavity affecting the whole edge or an indentation at middle; lunula bare; epandrium usually shining black or dark brown, sometimes bright yellow (most specimens from Namibia); lateral finger projecting or not outside of outer / lateral limit of anterior part of external hypophallic lobe as seen in ventral or dorsal view; distal part of external hypophallic lobe projecting or not beyond outer limit of proximal part in dorsal or ventral view; antlers curving upwards....................................................................... Bengalia peuhi Villeneuve  

- ST5 flap with a straight posterior edge, posterolateral corners drawn out dorsally (best seen in lateral view); lunula with two long setulae (holotype) or bare (male in CNC); epandrium yellow (holotype), concolorous with the abdominal tergites; lateral finger very small, not projecting outside of outer / lateral limit of distal part of external hypophallic lobe as seen in ventral or dorsal view; distal part of external hypophallic lobe projecting beyond outer limit of proximal part in dorsal or ventral view; antlers long, directed forwards and upwards, a slight bend at middle … [ Bengalia unicolor Séguy   , Oriental; see Rognes 2009]  

4 Fore femur with 2–7 pv spinous setae; fore tibia with a row of strong setae in proximal half of ventral surface; no or reduced fringe on hind tibia; median marginal pair of setae on T4 usually close together, their distance half the distance between discal setae of T5 (in B. aliena   , lacking T5 discals, distance variable) or even less; T5 with or without discal setae; distiphallus with an antler, or with a veil and a directly attached veil process.................................................... 5

- Fore femur without pv spinous setae; ventral surface of proximal half of fore tibia with or without spinous setae of variable size and strength; fringe present on hind tibia; median marginal setae of T4 not strikingly close together; discals on T5 present and strong, though one of them rarely may be weak or absent ( B. africanoides   sp. nov.); antler present in distiphallus......... 8

5 T5 usually without a pair of discal setae (one case observed [ Gabon MNHN] with a single weak discal seta); anepimeron with a group of about 3–7 black rather short setae near upper margin, usually quite strong and curved at tip (thicker at base than meral setae, but thinner at base than anepisternal setae, only half as long as meral setae), other setulae below this group yellow; hind tibia with weak fringe of 2–3 long and several weaker setae in distal half; fore femur with 4–5 pv spinous setae and long, slender and densely set setae on a and av side; fore tibia with a regular row of strong spines in proximal half, lowermost spine strongest and about as long as width of tibia, those above becoming gradually shorter, fringe of long slender setae in lower third; ST5 flap a very short and broad “crossbar”; distiphallus with antlers and upper lip.......... Bengalia aliena Malloch   - T5 usually with a pair of strong discal setae; anepimeron without strong setae near upper margin, the vestiture consists of black or pale long thin setae only; no fringe on hind tibia........................................................... 6

6 Frontal vitta practically bare, at most up to six sparse and exceedingly minute setulae; ST5 flap as in Fig. 234; anepimeron only with pale setulae or with very few black setulae in the upper part; distiphallus with a broad transparent fan-shaped antler (resembling a veil in apical view), at the base of which is prominent basal tooth; with a forwardly projecting upper lip; with a small lateral finger; veil, veil process and beak absent; opening of ejaculatory duct at level of apex of distiphallus........................................................................................... Bengalia wyatti (Lehrer)  

- Frontal vitta with numerous conspicuous short black setae all over; ST5 flap as in Fig. 249, or with a concavity in hind margin of varying depth, varying from an almost straight hind margin, to a very deep V- or U-shaped excavation (cf. figures in Rognes (2011a); anepimeron with yellow setulae only (very rarely a few black setulae in uppermost part) or with mostly black setulae; distiphallus without antler, without upper lip and without lateral finger; instead with a broad, more or less dorsally directed transparent veil on each side separated from its counterpart by a gap at the distal end of the middorsal wall, and with a more or less ventrally directed veil process originating laterally at the proximal part of the veil; usually with a prominent beak, a broad somewhat swollen structure at the anteriormost end of the ventral surface of the distiphallus (in bantuphalla   a beak is weakly developed); opening of ejaculatory duct very narrow, at tip of the beak, far behind and below apex of distiphallus; hypophallic lobe with its greatest extent facing anteroventrally or anteriorly; fore femur with 2–3 pv spinous setae................... 7

7 Anepimeron vestiture variable, from almost exclusively clothed with black setulae, to pale setulae present in lower two thirds and black setulae in upper third (holotype); distiphallus as in Figs. 243–247: veil process large, oval and flat and with small serrations near margins; external hypophallic lobe facing forwards (anteriorly), with a small dentate process dorsodistally; beak hardly differentiated; opening of the ejaculatory duct narrow, at the end of an upturned tube, far behind apex of distiphallus; long vertical rods (v.r.) on each side of the upturned tube carrying the opening of the ejaculatory duct; small triangular projections on underside of fore margin of lamella between the veils (magenta arrows in Figs. 244, 246, 247)............................................................................................ Bengalia bantuphalla (Lehrer)  

- Anepimeron almost always with yellow setulae only, though a few black ones may be present occasionally; distiphallus different: veil process variously shaped but never oval, usually long and narrow, rounded in cross section or flattened distally only; external hypophallic lobe facing downwards (ventrally or anteroventrally); beak very prominent; no long vertical rods and no small triangular projections in these positions............................................................................................... Bengalia spinifemorata   species-group, six remaining species (keyed by Rognes 2011a)

8 ST5 flap small; shorter than broad, with a hind edge that has two lateral convexities and a central shallow concavity ( Fig. 192); 3 post dc; anepimeron with all setulae black; fore tibia without ventral spinous setae; no distal finger in distiphallus ( Figs. 185, 186, 189)................................................................... Bengalia africanoides   sp. nov.

- ST5 flap different; 4 post dc; anepimeron with black setulae only or a considerable number of pale setulae in combination with a bundle of black setulae in upper part; fore tibia with or without ventral spinous setae; distal finger absent or present...... 9

9 Distiphallus with a pair of distal fingers of varying shape and strength situated on the inner side of the distal part of the dorsolateral wings (d.f. in Figs. 52, 53, 56, 58, 82, 83, 85, 88, 104, 109, 110, 128, 129, 132, 137, 158, 159, 161, 162) (Afrotropical species)............................................................................................ 10

- Distiphallus without distal finger (Oriental species).............. Bengalia peuhi   species-group (keyed by Rognes 2009)

10 ST5 flap distally convex ( Fig. 133); fore tibia without short v spine-like setae; hind tibia with a very sparse av fringe consisting of 5–7 thin setae on av side only, longest setae in fringe about as wide as width of tibia; anepimeron with dark setulae only, lower ones may appear yellowish in some lights.................... Bengalia roubaudi Rickenbach, Hamon & Mouchet  

- ST5 flap with distal margin evenly concave, or with a conspicuous medial V- or U- (or even almost O-) shaped excavation at middle of hind edge (rarely reduced to a small nick); fore tibia with or without v spine-like setae; hind tibia with a conspicuous or sparse av fringe; anepimeron with black (above) and yellow (below) setulae, or with almost all black setulae, yellow setulae confined to very small area posteriorly and ventrally (some B. depressa   )....................................... 11

11 ST5 flap ( Fig. 55) with a broad, evenly rounded shallow concavity affecting most of the hind edge; each posterolateral corner rounded at tip, the base of the ST5 flap much narrower than the width distally; fore tibia with one or two weak spine-like setae on ventral surface of proximal fourth, strongest at most three quarters of tibial width; fringe on lower half of hind tibiae weak, consisting of about 10 widely set long thin setae on av surface, hardly affecting v surface, not reaching pv surface.......................................................................................... Bengalia depressa Walker  

- ST5 flap with a conspicuous medial V- or U- (or even almost O-) shaped excavation at the middle of the hind edge only, rarely reduced to a small nick................................................................................ 12

12 ST5 flap with medial U-shaped excavation of variable width and depth; the hind edge lateral to the excavation evenly rounded ( Figs. 86, 87); fore tibia with distinct spine-like setae ventrally in proximal half; hind tibia with a dense fringe of long thin setae on the lower two thirds of av, v and pv surfaces..................................... Bengalia floccosa (Wulp)  

- ST5 flap with a posterior medial excavation, the corners between the lateral walls of the excavation and the hind edge usually rather sharp, likewise the corner between the hind edge and the lateral edges usually rather sharp, sometimes there is only a nick in the hind edge; fore tibia with or without ventral spine-like setae; fringe on hind tibiae usually extensive, but not or only slightly invading pv surface........................................................................... 13

13 Fore tibia without or with extremely weak and short ventral spine-like setae in proximal half; hind tibia with a less dense fringe of long thin setae on the lower two thirds or lower half of av and v surfaces, not reaching the pv surface; excavation in hind edge of ST5 flap variable ( Figs. 163–165), the excavation varying from a shallow V (or a small nick), to a U, to an almost circular hollowing-out with a narrow opening (in holotype of B. cuthbertsoni   ); the hind edge a little more oblique than in B. gaillardi   ........................................................................ Bengalia tibiaria Villeneuve  

- Fore tibia with a row of strong ventral spine-like setae on proximal third, strongest about as long as diameter of tibia; fringe present on lower two thirds of hind tibiae, rather dense on av and v surfaces, usually also affecting the pv surface slightly; ST5 flap with a conspicuous medial U-shaped, sharply set-off excavation in the middle third of the hind edge, the lateral parts of the hind edge usually forming two sharp corners on each side, one at the exit of the excavation, the other towards the lateral edge of ST5 flap; the hind edge of the ST5 flap rather transverse ( Fig. 106).............. Bengalia gaillardi Surcouf & Guyon  

CNC

Canadian National Collection of Insects, Arachnids, and Nematodes