Tanaostigma lasallei van Noort, 2020

Noort, Simon van & Copeland, Robert S., 2020, First record of the genus Tanaostigma (Hymenopteraı Chalcidoideaı Tanaostigmatidae) from the Afrotropical region with description of three new species, Journal of Natural History 54 (9), pp. 703-722 : 709-712

Tanaostigma lasallei van Noort sp. nov

( Figures 1(a – f) , 2(a – f ))

Holotype ♀ (deposited in SAMC), point mounted: SOUTH AFRICA, Kwazulu-Natal, Mabibi campsite , 50 m, 27°19.818 ′ S 32°44.792 ′ E, 18 – 20 October 2010, S. van Noort, Malaise trap, SA10-MAB-M01, Maputaland Coastal Belt, SAM-HYM-P082674, imaged WaspWeb, LAS 4.9, SAMC 2019.

Description of female

Size and colour. Length 3.3 mm. Head and body black with extensive areas of the head, mesosoma, and metasoma covered with white squamiferous setae, absent on mesopleura, antero-medial portion of mesoscutum, anterior half of scutellum, medial dorsal and anterior ventral areas of metasoma. Scape and pedicel orange-brown, anelli and first funicle segment dark brown grading into black for rest of flagellar segments except for last two club segments, which are orange-yellow. Distal two-thirds of hind tibiae orange. All tarsi yellow-orange, as is distal third of meso-tibia. Finer, white setae present on legs. Head ( Figure 1(e)) 1.3 times wider than high. Lateral ocellus closer to eye margin than to median ocellus (OOL:LOL: 0.37), situated directly adjacent to sharp occipital carinal crest, which curves inwards towards median ocellus. Scrobal impression shallow, glabrate. Inter-antennal projection small. Genal sulcus complete. Head sculpture elongate reticulate on face grading to imbricate on frons, with evenly dispersed white squamiferous setae present on face and frons, grading into normal white setae on vertex, setae largely absent on posterior of head including genae posterior of genal sulcus. Mandible tridentate ( Figure 2(a )). Antenna ( Figures 2(a,b )) with scape 4.7 times longer than wide, with flattened ventral expansion present on distal half. Pedicel 1.5 times longer than wide. Two anelli, first about half as long as, and slightly narrower than second. First funicular segment longer than wide, F2-F4 as wide as long, F5-F6 wider than long, not laterally compressed. Club 1.4 times longer than wide, proximally as broad as preceding funicle segment, narrowing to tip.

Mesosoma dorsally minutely reticulate, punctiferous where setae present, covered with white squamiferous setae, except for mesoscutum anterior of notauli and axillae which have small, fine white setae. Notauli complete but indistinct posteriorly, meeting before trans-scutellar articulation. Scutellum ( Figure 1(d)) without lateral glabrate area, devoid of white setae in anterior third, replaced by small, fine brown setae. Propodeum ( Figure 2(d)) laterally glabrate to medially reticulate with complete medial carina; metanotal trough with two large metanotal fovea laterad of central smaller fovea, with narrow elongate fovea anteriorly situated, extending medially beyond central fovea. Mesopleuron ( Figure 1(c)) dorsally reticulate, ventrally elongate reticulate, medially finely reticulate, without setae. Sternopleural suture fused with mesopleural suture. Metapleuron covered with a dense cluster of long white setae ( Figure 1(c)) ; which extend to the proximal dorsal surface of the hind coxa. Leg segments laterally flattened; all tibiae with sharp dorsal margin. Hind femora with a distal ventral angulate extension, curving inwards to end of femur; hind tibiae with a proximal dorsal carina. Wings hyaline, except for fore wing ( Figure 1(f)) which has a medial infuscate patch extending from marginal and stigmal veins halfway towards apical and ventral margins in an axe shape; larger, modified, dark setae present below marginal vein grading outwards into normal setae; small triangular patch of larger more widely dispersed setae present directly below submarginal vein, adjacent to glabrous area. Venation dark brown, submarginal vein lighter. Stigmal vein strong, distinctly curved, longer than post-marginal vein. Fore wing marginal fringe present apically, extending ventrally to anal angle. Costal cell: marginal vein: stigmal vein: postmarginal vein = 50:32:15:12.

Metasoma ( Figure 2(f)) with elongate reticulate surface sculpture; T2 with transverse rows of scattered setae, T3-T5 without setae medially; T6 with a row of setae anteriorly, T7 with setae laterally. Posterior margin of T2 with shallow medial invagination; faint medial line present; posterior margin of T3-T7 straight, without medial incision, or medial line. Ovipositor short. Each pygostyle with four setae, two extremely elongate, half as long as metasoma, the remaining pair half this length.

Male. Unknown.

Diagnosis. Tanaostigma lasallei is distinguished from other Tanaostigma by having an infuscate area on the fore wing ( Figure 1(f)) . The modified setae are restricted to a small patch below the marginal vein and do not contribute to the colour pattern on the wing. Presence of modified setae is shared with the Neotropical species T. stanleyi , which however has a patterned appearance as a result, and the other two African species where the setae form an obvious dark transverse band. The stigmal vein is strongly curved ( Figure 1(f)) . Scutellum lacks lateral glabrate area ( Figure 1(d)) ; and posterior margin of T2-T4 without medial incision ( Figure 2(f)) . All three of these character states are shared with the other two African species, which have a very different wing pattern, and with the Neotropical T. stanleyi , which, in contrast to the black African species, is strikingly coloured with pink, orange and white areas on the pleural regions and face. The remaining species of Tanaostigma have a straight stigmal vein, glabrate areas on the scutellum and medial incisions on the metasomal tergites. Notauli of T. lasallei are complete, but indistinct posteriorly, whereas the other two African species have incomplete notauli and the New World and Oriental species have distinct, complete notauli.

Affinities. This species shares antennal morphology with the other two African species, and this is most similar to the Neotropical species, T. slossonae , which also has funicular segments that are not flattened, but which are subequal in length. The fore wing has only a small patch of weakly modified setae below the marginal vein, and does not have the extensive modified setae on the fore wing of the other two African species, but this shared character state suggests a possible relationship with the Neotropical species, T. stanleyi .

Etymology. The species is named in memory of John LaSalle. Genitive case.

Distribution. South Africa. Only known from Kwazulu-Natal Province.

Biology. Unknown.

Habitat. Coastal bushveld/grassland.

Figures

Figure 1. Tanaostigma lasallei Holotype female. (a) Habitus, lateral view (b) Habitus, dorsal view (c) Head and mesosoma, lateral view (d) Head and mesosoma, dorsal view (e) Head, anterior view (f) Wings (inset: data labels).

Figure 2. Tanaostigma lasallei Holotype female. (a) Clypeus and mandibles (b) Antenna (c) Pedicel and anelli (d) Scutellum, metanotum and propodeum (e) Trans-scutellar suture (f) Metasoma, dorsal view.