Polynema (Polynema) sagittaria van Noort & Triapitsyn

Noort, Simon van & Triapitsyn, Serguei V., 2018, Revision of the Polynemadikobraz species-group with description of a remarkable new species from South Africa (Hymenoptera, Chalcidoidea, Mymaridae), ZooKeys 783, pp. 67-84 : 67

Polynema (Polynema) sagittaria van Noort & Triapitsyn sp. n. Figs 1 A–F, 2 A–F, 3 A–F, 4 A–D

Material.

Holotype ♀ (deposited in SAMC), point mounted: SOUTH AFRICA, Western Cape, Cederberg, Sawadee Farm, 32°19.92'S, 18°59.24'E, 24-28.ix.2003, S. van Noort, Malaise trap, CE03-M01, Dry Mountain Fynbos, 380 m, SAM-HYM-P086324, imaged WaspWeb, LAS 4.9, SAMC 2017. Paratypes. SOUTH AFRICA, Western Cape: same data as holotype, except for collecting event number: CE03-M05, and catalogue number: SAM-HYM-P086325, imaged WaspWeb, LAS 4.9, SAMC 2017 (1 ♀ on slide, SAMC); Banghoek Valley, Dwarsriviershoek Farm, 33°56.23'S, 18°57.71'E, 410 m, 22. x– 27.xi.2013, S. van Noort, Malaise trap, Mesic Mountain Fynbos, BH12-FYN3-M14, SAM-HYM-P084138 (1 ♀ on slide, SAMC) [specimen lacks both hind wings; DNA was extracted using a non-destructive method, John M. Heraty's Laboratory molecular voucher D6195]; Kogelberg Nature Reserve, 34°16.48'S, 19°01.03'E, 16. x– 16.xi.1999, S. van Noort, Malaise trap, K098-M44, Mesic Mountain Fynbos, last burnt c. 1988, SAM-HYM-P082695 (1 ♀ on point, SAMC); 10 km S of Citrusdal, Kornlandskloof [S32°40', E19°02], 7-9.x.1994, meadow at stand of Herrea blanda , M. Sodelund, MT (1 ♀ on point, CNCI).

Etymology.

The species epithet “sagittaria” is Latin for armed with bow, with reference to the bowed ovipositor sheaths. Noun in apposition.

Diagnosis.

The highly modified ovipositor immediately distinguishes this species from all other described Polynema species in Africa. Morphologically similar to the recently described species, P. dikobraz from Madagascar, and the second undescribed Madagascan species, all three species having similar modified fore wing microtrichia.

Affinities.

Based on the putative morphological synapomorphy of modified microtrichia on the fore wing disc, P. sagittaria is clearly related to P. dikobraz , but has more numerous, shorter modified wing disc microtrichia than in P. dikobraz . The extensive external ovipositor housing is an obvious distinction within the P. dikobraz species-group, but this is likely to be a character state that has evolved independently in a number of mymarid genera (see discussion).

Distribution.

South Africa. Only known from the Western Cape Province.

Habitat.

Mountain fynbos, a vegetation type specific to the Cape Floral region.

Description of female holotype.

Size and colour. Total length of body, with head in prognathous position, 1700 µm. Head 205; mesosoma 511; petiole 114; metasoma 1140; ovipositor 2110 folded, 3800 total length (unfolded). Antenna: radicle 18; rest of scape 96; pedicel 91; F1 92; F2 204; F3 173; F4 115; F5 97; F6 94; clava 204. Fore wing 1670: 340; longest marginal seta 517; longest discal (spine-like) seta 117. Hind wing 1260: 23; longest marginal seta 267. Habitus (Fig. 1A, B). Head dark brown to black on vertex, face and mesosoma yellowish-brown, pedicel and anterior third of metasoma yellowish, rest of metasoma dark brown; scape dark brown, pedicel and F1-F6 yellowish, clava dark brown; legs yellowish.

Head (Figs 1E, 2B, 3A). Mandible 3-dentate. Antenna (Figs 2 C–E): scape coriaceous, 2 × as long as wide in lateral view (excluding a short radicle); pedicel as long as F1; F2 the longest funicular segment, F3 longer than the following funicular segments, F4 a little longer than F5, the latter slightly longer than F6, F6 with one mps; clava long, 4 × as long as wide, with 4 mps (3 apical and 1 subapical).

Mesosoma (Figs 1 C–D, 1F, 3D). Coriaceous. Pronotum mediolongitudinally divided, with numerous stout, truncate setae, collar with two strong truncate setae. Mesoscutum 1.8 × as wide as long, 0.75 × scutellar length. Axilla with 1 strong truncate seta (30 µm). Scutellum with a row of tiny, indistinct foveae on frenal line; with two anterior truncate setae. Propodeum smooth, with a truncate seta each side of the midline. Fore wing (Figure 2F) 4.9 × as long as wide; submarginal vein without seta, marginal vein with 1 dorsal seta; longest marginal seta 0.785 × maximum width of wing; disc with a distinct apical brown patch in close apposition to wing margin, occupying approximately a third of wing disc length; brownish areas in apical third of disc among spine-like microtrichia; disc setose throughout (apical two thirds of disc with normal microtrichia), with 130-140 very long, dark brown, strongly enlarged spine-like modified microtrichia (Figs 1A, 2F, 3E, 3F) on proximal brown infuscation area on wing disc. Hind wing (Figs 2F, 4A) 54.8 × as long as wide; apex of venation with a short, thickened seta; disc slightly infumate, longest marginal seta 11.6 × maximum width of wing. All coxae smooth.

Metasoma (Figs 2A, 3C). Petiole smooth, approximately 3 × as long as wide, slightly longer than metacoxa; ovipositor extending anteriorly in metasomal sac between the legs, 1.3 × further forward than head length; doubled back on itself in a bow-like fashion, with complex fold at anterior extremity (Figure 4B); only slightly extending beyond the metasomal apex by 0.05 × metasomal length, 1.24 × length of body in folded position (Figure 2A), 2.23 × length of body if totally extended in unfolded position; ovipositor valve with 10 closely-spaced, indistinct, terminal annuli; pre-terminally with three unevenly spaced dorsal notches (Figure 4C).

Variation.

Body length 1.45-1.68 mm; ovipositor (folded) length 1.93-2.00 mm in the paratype specimens.

Male.

Unknown.