Tanaostigma mulu van Noort 2020, sp. nov
Creators: name: Noort, Simon van
name: Copeland, Robert S.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Tanaostigmatidae
Tanaostigma
Tanaostigma mulu

description: Tanaostigma mulu van Noort sp. nov
(Figures 3(a – f), 4(a – f))
Holotype ♀ (deposited in NMKE), point mounted: KENYA, Eastern Prov., Mulu Musingila Farm, 689 m, 2.11412° S. 38.23989° E, Malaise trap, farmland near small, seasonally wet area, 11 – 25 December 2017, R. Copeland, Tanaostigma, 6904 – 23, ICIPE 10307, USNMENT-01448450, imaged WaspWeb, LAS 4.9, SAMC 2019.
Description of female
Size and colour. Length 1.7 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 orange-brown, pedicel brown, flagellar segments black except for last club segment, which is orange-yellow. Distal two-thirds of hind tibiae yellow-orange. All tarsi yellowish-orange, as are distal quarter of pro and mesotibiae, and apex of hind femora. Finer, white setae present on legs.
Head (Figure 1(e)) 1.35 times wider than high. Lateral ocellus closer to eye margin than to median ocellus (OOL:LOL: 0.66), 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 more normal white setae on vertex, setae largely absent on posterior head including genae posterior of genal sulcus. Mandible not visible (obscured by legs). Antenna (Figure 3(b,c)) with scape 3.6 times longer than wide, with flattened ventral expansion present on distal half. Pedicel 1.4 times longer than wide. Two anelli, first about half as long as, and slightly narrower than second. First two funicular segments as wide as long, remaining segments wider than long, not laterally compressed. Club 1.5 times longer than wide, proximally almost as broad as preceding funicle segment, gradually 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 incomplete, absent posteriorly. Scutellum (Figures 3(d) and 4(d)) without lateral glabrate area, devoid of white setae in anterior third. Propodeum (Figure 4(d)) laterally glabrate, medially reticulate with no medial carina; metanotal trough with three large metanotal fovea, not extending medially beyond small central metanotal fovea. Mesopleuron (Figure 3(c)) dorsally with reticulate surface sculpture, ventrally with elongate reticulate sculpture, medially finely reticulate, without setae. Sternopleural suture fused with mesopleural suture. Metapleuron covered with a dense cluster of long white setae (Figure 3(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; fore wing (Figure 3(f)) with transverse band of dark, modified setae; fore wing twice as long as wide. Venation light yellowish-brown. Stigmal vein strong, distinctly curved, as long as postmarginal vein. Fore wing marginal fringe present apically, extending ventrally to anal angle. Costal cell: marginal vein: stigmal vein: postmarginal vein = 14:9:4:4.
Metasoma (Figure 4(f)) elongate reticulate; T1 with transverse rows of scattered setae, T3-T5 without setae for most of the dorsal medial surface; T6 with two rows of setae, only absent on midline. Posterior margin of T2 with shallow medial invagination; 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.
Comments. The trans-scutellar sutural membrane is exposed and expanded in the specimen of T. mulu giving it a very different mesosomal appearance than the two other species that have the potential articulation between the mesoscutum and scutellum in the normal closed position.
Diagnosis. Tanaostigma mulu is distinguished from other Tanaostigma by having a band of strongly modified dark setae on the fore wing (Figure 3(f)), except for T. umkumbusho, which has a much more obvious dark transverse band, a longer stigmal vein and more elongate fore wing. Presence of modified setae is shared with the Neotropical species T. stanleyi, which, however, has a patterned appearance. The stigmal vein is strongly curved (Figure 3(f)). Notauli incomplete, absent posteriorly, a character state shared with T. ukumbusho, all other species have complete notauli. The scutellum lacks the lateral glabrate area (Figure 4(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, and 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.
Affinities. Based on the putative morphological synapomorphy of modified setae on the fore wing T. mulu is most closely related to T. ukumbusho, these two species probably forming a monophyletic clade, sister to the next most similar species, T. lasallei, which, however, only has a small patch of weakly modified setae below the marginal vein. All three of these African species are possibly related to the Neotropical T. stanleyi, which also has extensive patches of modified fore wing setae, albeit in a different patterned configuration. Like the other African species, T. mulu does not have flattened or widened funicular segments suggesting a similarity to the Neotropical species, T. slossonae, which also has funicular segments that are not flattened, but which are subequal in length.
Etymology. The species epithet ‘mulu’ is Kiswahili (a widely spoken East African language) for ‘ heap ’, referring to the heaped or humped appearance of the mesosoma in lateral view, and is also the first part of the name of the farm encompassing the type locality. Noun in apposition.
Distribution. Kenya. Known only from Eastern Province.
Biology. Unknown.
Habitat. Farmland near small, seasonally wet area.
description: Published as part of 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, pp. 703-722 in Journal of Natural History 54 (9) on pages 712-715, DOI: 10.1080/00222933.2020.1746426, http://zenodo.org/record/4290471