Usia turaco Gibbs, 2011

Gibbs, David, 2011, 2960, Zootaxa 2960, pp. 1-77 : 70-73

Usia turaco Gibbs sp. nov.

( Fig. 14, Plate XXI)

Type material examined. HOLOTYPE: Algérie [ Algeria], Rouiba, J. Surcouf, Mai-Juin 1911/ ♂ / Usia novakii Strobl ♂ / coll. Henré-Bazia [♂ in MNHN] . PARATYPES: Algérie, Rouiba, J. Surcouf, Mai-Juin 1911/ Museum Paris / coll. J. Surcouf 1919 [♀ in MNHN]; Algérie, Rouiba, J. Surcouf, Mai-Juin 1911/ Usia novakii Strobl ,

= pusilla Macq. [sic]/ Museum Paris / coll. J. Surcouf 1919 [♀ in MNHN]; Algérie, Rouiba, J. Surcouf, Mai-Juin 1911/ Ex. Coll., Aldgren B. [♂ in PCJD].

Etymology. noun in apposition, from the tropical African bird genus Turaco ( Aves Musophagidae ); refers to the tip of the epiphallus which, in lateral view, is reminiscent of the head of some long-crested members of this genus.

Diagnosis. A small black species (the holotype is brown so is possibly faded) with short, adpressed hairs on hind femora ventrally, marginal hairs of scutellum about as long as half length of scutellum medially, mesonotum relatively smooth and shining. Male genitalia very small and folded under the tip of the abdomen and easily overlooked, epandrium quadrate with rounded triangular extensions that wrap around cerci and lack and wavy-tipped hairs. Female only identifiable by examination of apical sternite and genitalia (Plate XXI).

Description. Measurements. Body length. 2.5–3.4mm Wing length. 2.3–3.5mm.

Male. Known from just 2♂ and 2♀ so range of variation could be greater than apparent from the following description. Head. Frons about a fifth head width, at narrowest point about as wide as length of third antennal segment, rather matt with at most faint white dust spots on anterolateral corners. Evenly widening towards front. Mouth margin very narrow, practically absent, broader and paler level with antennae. Ocellar triangle very slightly obtuse, almost equilateral, lateral ocelli separated from the eye by their diameter or a little less. Longest hairs on ocellar tubercle short, about as long as width between lateral ocelli and appreciably shorter than width of frons at vertex. Occiput covered with grey dust, including area behind vertex which is slightly more shining, and relatively short black hairs, shorter above, longer below. Antennae black to brown, relatively short, third segment obovate, less than twice as long as scape and pedicel combined, almost bare above. Proboscis black, naked, about as long as mesonotum. Palps very small, black with small apical setae. Thorax. Entirely black to dark brown, mesonotum shining and mostly smooth, lightly pale-dusted on pronotum, postpronotal lobe, notopleuron and above wing. Hairs short, on disc of mesonotum similar to that on vertex, acrostichals bi- to triserial, paramedian lines bare back to level of wing base, lateral hairs evenly distributed becoming longer on notopleuron. Scutellum shining, disc a little more sparsely haired than mesonotum, marginal hairs longer but barely exceed half the length of the scutellum. Pleurae black to brown, predominantly covered in pale dust, a shining strip along hind edge of anepisternum and katepisternum ventrally also dust-free. Anepisternum with dark hairs similar to those on mesonotum in upper half and posterior margin. Wing. Clear to vaguely tinged brownish yellow, veins pale brown. Anal lobe convex, almost as wide as anal cell. Haltere. Yellow-white knob, stem infuscated. Legs. Black to brown, coxae dusted, otherwise shining but with rough texture to cuticle, with very short, adpressed dark hairs, the longest on base of hind femora posteroventrally, but even these barely exceed width of tibia. Hairs shorter and denser on tibia. Abdomen. Black to brown, short with very broad tergites, rough surface sculpture of short, transverse welts at hair insertions, covered with relatively short dark hairs, in the paratype ♂ hairs on apical tergites curled over at tips. Genitalia. Small, rather globular and retracted under the tip of the abdomen to the extent that it is possible to mistake the sexes. Epandrium with large, rounded, subapical projections that, in dry specimens, wrap around the cerci and tip of gonocoxite. Epandrium rather evenly covered with short, dark hairs, gonocoxite with longer hairs.

Female. Very similar to male, frons marginally wider, dust spots a little more conspicuous and ocellar triangle more obtuse. Mouth margin also a little broader. Hairs generally shorter, especially on tergites 1–4; on mesonotal vestiture sparser, bare paramedian lines more obvious. Sternite eight broadest basally, quite clearly embossed in basal half, apicomedially with a squarish translucent patch, apically with two lobes, divided medially, thus quite distinct from other species so far examined.

Discussion. This very little known species is not obviously related to any other Micrusia , the male genitalia being unlike any other species. The short hairs and epiphallic structure perhaps indicate an affiliation with the U. pusilla complex.

Distribution. Algeria. Only known from the type series of four specimens collected by Surcouf in 1911, probably all from same location in western Algeria and on same date. Although it would not be too surprising if also found in adjacent parts of Morocco, it would seem to be exceedingly rare and local.

PLATE XXI. Usia turaco Gibbs sp. nov.; a epiphallic complex ventral, b epiphallic complex lateral, c gonocoxite ventral, d gonocoxite lateral, e epandrium dorsal, f epandrium lateral, g female genitalia ventral, h female sternite 8 ventral.

versicolor -species group

Included species: