Vitreostigmus Boehmova & Jansta, 2022

Boehmova, Julie, Rasplus, Jean-Yves, Taylor, Gary S. & Jansta, Petr, 2022, Description of two new Australian genera of Megastigmidae (Hymenoptera, Chalcidoidea) with notes on the biology of the genus Bortesia, Journal of Hymenoptera Research 90, pp. 75-99 : 75

publication ID	https://dx.doi.org/10.3897/jhr.90.82582
publication LSID	lsid:zoobank.org:pub:9B6E1A56-2D68-412B-A71C-D3C9EF69BA1F
persistent identifier	https://treatment.plazi.org/id/2B9B9E87-25F7-470F-9445-8C4E568A7C06
taxon LSID	lsid:zoobank.org:act:2B9B9E87-25F7-470F-9445-8C4E568A7C06
treatment provided by	Journal of Hymenoptera Research by Pensoft
scientific name	Vitreostigmus Boehmova & Jansta
status	gen. nov.

Treatment

Vitreostigmus Boehmova & Jansta View in CoL gen. nov.

Figs 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5

Type species.

Vitreostigmus kangarooislandi Böhmová and Janšta, by present designation.

Etymology.

Named after the transparent stigma which distinguishes the new genus from other genera of Megastigmidae . Masculine gender.

Diagnosis.

Vitreostigmus can be distinguished from other genera of Megastigmidae by the following combination of characters: clypeus medially with one tooth (Fig. 3B View Figure 3 ); F1-F5 more than twice as long as broad; each flagellomere with two (in females) or three (in males) rows of MPS (Figs 2E View Figure 2 , 3F View Figure 3 , 5E View Figure 5 ); pronotal collar delimited by transverse pronotal carina and with some additional incomplete transverse striae (Figs 2B View Figure 2 , 5D View Figure 5 ); mesoscutellum without frenal area, broadly touching transscutal articulation with small fovea separating disc of metascutellum from transscutal articulation (Figs 3E View Figure 3 , 4B View Figure 4 ); propodeum long, about 0.50 × as long as broad; postspiracular furrow well developed (Figs 2F View Figure 2 , 3D View Figure 3 ); lower metepisternum with propodeal foramen oval, posteriorly narrower than anteriorly (pear-like shape); surface of lower metepisternum irregularly carinated, two additional carinae originate submedially from anterior margin of propodeal foramen, going forward in parallel and turning outwards to anterior margin of metacoxal foramen (Fig. 2G View Figure 2 ); fore wing with at least two infumations; stigma large, elongated, and transparent (Fig. 3G View Figure 3 ); tip of hypopygium reaching about 0.75 × of length of gaster, but its tip narrow, fingerlike, projecting (Fig. 2I View Figure 2 ); ovipositor about 0.8 × as long as metasoma (Figs 2A View Figure 2 , 3A View Figure 3 ).

In the key of Bouček (1988) Vitreostigmus goes to couplet 19 (page 121) but differs from Bortesia by having, e.g., more intensive metallic color, pronotal collar carinated, long propodeum, and stigma transparent, and from Bootanelleus by having antennae inserted above lower margin of eye and stigma elongated and transparent and ovipositor shorter than metasoma.

Generic description.

Female. Body length excluding ovipositor 2.12-2.66 mm; length of ovipositor 0.78-0.96 mm. Body light brown yellow. At least part of vertex, upper face, lower face laterally, posterior part of mesoscutal midlobe, posterior half of mesoscutellum, axilla, callus posterior to spiracle, propodeum and metapleuron blue green violet. Pronotal collar, lateral lobe of mesoscutum, lower mesepisternum, and metasomal tergites at least with weak violet tint. Fore wing with at least a brown macula under parastigma and around stigmal vein; submarginal vein light brown, marginal and postmarginal vein light brown yellow to white, stigmal vein translucent, sometimes appearing white.

Head. Vertex and at least upper face reticulate; malar space, temple, and gena coriaceous; occiput alutaceous. Temple 0.23-0.38 × as long as eye. Eyes separated by 1.02-1.11 × their own height, inner eye margins slightly diverging dorsally. Face with white setation; setae long and lanceolate, denser on lower face (Figs 2C, D View Figure 2 , 3B View Figure 3 ). Scrobes shallow, not deeper than scape breadth, upper margin below imaginary line connecting dorsal margins of eyes; interantennal process reaching to about 0.33 × of scrobes length. Clypeus delimited by weak sulcus laterally and posteriorly, medially with one tooth. Malar space 0.45-0.50 × as long as breadth of oral fossa and 0.37-0.44 × as long as eye height. Occipital carina present and well developed. Torulus inserted above ventral level of eye, but below centre of face. Anellus breadth slightly narrower than F1 breadth. F1-F5 more than twice as long as broad. Each segment with two rows of MPS; micropilosity area very small and restricted to third claval segment. First claval segment with two rows of MPS, the other two with one row of MPS. Ocelli small, POL 1.31-1.39 × as long as OOL, OOL 1.68-2.25 × as long as POD.

Mesosoma. Mesosoma 2.13-2.20 × as long as broad, covered irregularly with sparse relatively long white setae dorsally. Pronotum 0.80-0.85 × as broad as mesoscutum. Pronotum with pronotal collar well delimited by transverse pronotal carina; pronotal neck about as long as pronotal collar. Pronotal collar with some incomplete transverse striae. Mesoscutal midlobe reticulate with narrow smooth anterior part usually hidden under pronotal sclerite. Mesoscutal lateral lobes striate. Notauli well developed, foveated and whitish. Mesoscutellum with foveated marginal rim and without frenal area; anterior margin broadly touching transscutal articulation with small fovea separating disc of mesoscutellum from transscutal articulation; breadth of anterior mesoscutellar margin about half of posterior breadth of mesonotum. Mesoscutellum reticulate dorsally, with denser reticulation posteriorly, with two rows of several setae submedially. Axilla reticulate-striate. Scutoscutellar sulcus separating axillae foveate-septated. Propodeum long, about 0.50 × as long as broad, irregularly longitudinally striate. Callus with smooth sculpture bearing long setation. Propodeal spiracle small and rounded, about 1.30 × as far from anterior margin of propodeum as spiracle diameter. Postspiracular furrow developed as deep sulcus. Metacoxal flange developed as sharp flange. Lower metepisternum (Fig. 2G View Figure 2 ) with propodeal foramen oval, posteriorly narrower than anteriorly (broad pear-like shape), its anterior end below imaginary line drawn across posterior margin of metacoxal foramina; metacoxal foramina as far from each other as anterior diameter of propodeal foramen. Lower metepisternum anteriorly delimited by transverse concave carina connecting anterior margins of metacoxal foramina; medially carina rising in front of metafurcal pit. Surface of lower metepisternum with several irregular and incomplete transverse and longitudinal carinae; two additional carinae originate submedially from anterior margin of propodeal foramen, going forward in parallel and turning outwards to anterior margin of metacoxal foramen. Metatibia with two spurs, but shorter spur minute, about 0.33 × as long as longer spur; longer spur shorter than basimetatarsus. Fore wing about 2.60 × as long as wide, with infumation ventrad to parastigma and around stigmal vein; setae on disc dense and brown; speculum small reaching more or less only to end of parastigma; basal cell bare; basal setal line with a few setae dorsally; basal vein present but rudimentary, visible only as sclerotized fold in its posterior part; marginal vein 0.78-0.92 × as long as postmarginal vein and 1.38-1.47 × as long as stigmal vein; stigma large and elongated, 2.78-5.00 × as long as broad; uncus with four uncal sensilla in row; venation pale brown, stigma vein posteriorly and stigma transparent (in some specimens white due to drying).

Metasoma. Petiole transverse, several times broader than long. Metasoma slightly longer than mesosoma. Gaster with very shallow alutaceous sculpture; Gt1-Gt4 incised medially; tip of hypopygium reaching about 0.66-0.75 × of length of gaster, but its tip narrow, fingerlike, projecting. Ovipositor about 0.80 × as long as metasoma.

Male. Only the male of V. kangarooislandi is known. Color and sculpture similar to females, sometimes more extensively metallic; antenna with scape shorter, hardly reaching ventral margin of anterior ocellus; combined length of pedicel and flagellum about 2.5 × as long as breadth of head; stigma large and broadly ovoid and brown; propodeum with irregular reticulate sculpture; all gastral tergites margins straight; funicular segments of the large male with three rows of MPS.

Comments.

Vitreostigmus and Bortesia share several characters: single median tooth on clypeus, stigma lengthened in female, and ovipositor upturned and no longer than gaster ( Riek 1966; Bouček 1988). However, Bortesia have the antennae inserted above the centre of face, a short pronotal collar which is bluntly angled (Fig. 6A View Figure 6 ), mesoscutellum anteriorly as broad as mid lobe of mesoscutum posteriorly, notauli almost meeting scutoscutellar sutures, and a short propodeum about 0.25 × as long as broad and smooth to finely reticulate with no striae. Additionally, females of Bortesia have the stigma brown to bright brown (Fig. 6A, C View Figure 6 ), funiculars F2-F7 at most 2 × as long as broad and bearing only one row of MPS (Fig. 6B View Figure 6 ). Bortesia females are non-metallic or at most with metallic hue while females of Vitreostigmus exhibit metallic coloration. In addition to the characters listed above, males of Bortesia differ from males of Vitreostigmus in exhibiting extensive metallic coloration (Fig. 6D, E View Figure 6 ), scape shorter than F1 (Fig. 6F View Figure 6 ), funicular segments flattened laterally, broadened and ventrally convex, and MPS partially sunken in funicular segments (Fig. 6G View Figure 6 ).