Parastephanellus evexus Tan & van Achterberg, 2018

Tan, Jiang-Li, Achterberg, Cornelis Van, Tan, Qing-Qing, Zhou, Tong & Li, Tao, 2018, Parastephanellus Enderlein (Hymenoptera: Stephanidae) revisited, with description of two new species from China, Zootaxa 4459 (2), pp. 327-349 : 336-340

Parastephanellus evexus Tan & van Achterberg , sp. n.

Figs 43–61

Parastephanellus brevistigma ; Chen et al. 2016a: 119 –122 (♂).

Type material. Holotype, ♀ ( NWUX): “[SE China:] Jiangxi, Quannan, 650 m, 16.vi.2008, Sichang Li ” . Paratypes: 1 ♂ ( NWUX): topotypic and same data ; 1 ♂ ( SCAU): “[SE China:] Guangdong, Nanling National Nature Reserve, 6.x.2004, Zaifu Xu ”

Diagnosis. Ivory streak of temple distinctly contrasting with dark brown posterior part of temple in lateral view ( Fig. 46 ), separated from occipital carina in dorsal view ( Figs 53 , 60 ); temples of ♀ strongly angulate in dorsal view ( Fig. 53 ); frons of ♀ dark brown; medio-anteriorly pronotum gradually arising behind neck ( Figs 43 , 47 ); pronotum below tegulae costate ( Fig. 47 ); posterior part of pronotum and mesoscutum moderately high in lateral view ( Fig. 43 ); vein 1-M of fore wing approx. 1.2 × vein m-cu and 1.8–1.9 × vein 1-SR ( Fig. 45 ); vein 1-SR of fore wing strongly angled with vein 1-M and as long as vein 2-M+CU1 ( Fig. 45 ); vein m-cu of fore wing approx. 1.5 × longer than vein 2-SR+M; sclerotized part of vein 2-M of fore wing up to level of apex of vein r; first metasomal tergite of ♀ very slender and approx. 9.5 × as long as wide ( Fig. 44 ); pygidial area of ♀ moderately emarginated apically, not protruding and rounded latero-apically ( Fig. 54 ); ovipositor sheath approximately as long as body and 1.8 × as long as fore wing.

Runs in the key to Parastephanellus by Elliott (1928) either to P. rubripictus Elliott, 1917 , or to P. crassicoxae Elliott, 1928 . The new species differs from P. rubripictus by having the frons coarsely vermiculate-rugose (rugosepunctate in P. rubripictus ), the moderately wide and medium-sized pterostigma (long and narrow), the first tergite 0.8 × as long as remainder of metasoma (of equal length), the neck with transverse carinae (with longitudinal carinae) and the coarsely foveolate propodeum (coarsely reticulate-rugose). It differs from P. crassicoxae by having the hind coxa elongated (very stout in P. crassicoxae ), the coarsely foveolate propodeum (reticulatepunctate) and the propleuron largely smooth (transversely aciculate).

Description. Holotype, ♀, length of body 13.5 mm, of fore wing 7.6 mm, and of ovipositor sheath 13.0 mm.

Head. Antenna incomplete, with 10 segments remaining, third segment with one circular sensillum ventrally, fourth segment with 4 circular sensilla; frons coarsely vermiculate-rugose ( Fig. 52 ); three anterior coronal teeth large and lobe-shaped ( Fig. 53 ), both posterior ones wider and arcuate; vertex largely coarsely rugose anteriorly, largely smooth posteriorly, only medially transversely aciculate; temple strongly convex, smooth and shiny ( Fig. 46 ), angulate in dorsal view ( Fig. 53 ).

Mesosoma. Neck short and transversely carinate, anteriorly distinctly emarginated ( Figs 46–48 ), posteriorly with transverse groove in front of oblique posterior part of pronotum ( Fig. 47 ), posterior part rugulose medioanteriorly, costate below tegula ( Figs 47, 48 ); propleuron largely smooth and shiny except laterally; mesopleuron rather shiny (except anteriorly), superficially coriaceous and medially foveolate ( Fig. 47 ), anteriorly densely yellowish setose; scutellum finely aciculate medially and with foveolae laterally ( Fig. 48 ); propodeum coarsely foveolate and with narrow coriaceous interspaces ( Figs 47, 48 ); metapleuron very coarsely foveolate, convex medially.

Wings. Fore wing ( Fig. 45 ): pterostigma 5.8 × as long as wide and rather abruptly rounded apically; vein 1-M 1.9 × as long as vein 1-SR and 1.2 × vein m-cu; vein 1-SR as long as vein 2-SR+M; vein cu-a distinctly antefurcal and reclivous; vein 2-SR 1.5 × as long as vein r; vein r ends near level of apex of pterostigma; basal part of pterostigma twice as long as apical part ( Fig. 43 ); vein 1-M and vein r distinctly curved; vein 1-SR as long as parastigmal vein; vein 3-CU1 largely nebulous and widened posteriorly, only basal 0.1 tubular ( Fig. 45 ).

Legs. Hind coxa elongated, 3.4 × longer than wide, with small flattened granulate dorso-lateral area ( Fig. 49 ), largely coarsely rugose; hind femur coriaceous, ventrally with 2 large teeth and one smaller basal tooth ( Fig. 50 ); hind tibia 1.2 × as long as hind femur, largely coriaceous and ventrally with oblique carinae, inner side with distinct v-shaped impression, basal narrow part of hind tibia as long as widened part; ventral length of hind basitarsus 4.7 × as long as wide.

Metasoma. First tergite densely transversely striate, 9.5 × as long as its maximum width ( Fig. 44 ), 2.5 × second tergite and 0.8 × metasoma without first tergite; second tergite basally with some rugae; remainder of metasoma rather shiny and very superficially cellular-coriaceous; pygidial area triangularly depressed, apically moderately circularly emarginated and latero-apically rounded, not protruding ( Fig. 54 ); ovipositor sheath nearly as long as body ( Fig. 43 ).

Colour. Black or blackish brown; temple with ivory streak along eye long, well differentiated and nearly up to occipital carina ( Figs 46, 53 ); middle tibia basally and narrowly apically and most of middle basitarsus white; remainder of tarsi and four basal antennal segments brown; palpi pale yellowish but basally dark brown; face, temple posteriorly, frons ventrally, pronotum ventrally, propleuron, fore leg largely (except tarsus), middle coxa and femur, metasoma apically and ventrally (except first tergite), hind tibia largely, pterostigma (except whitish base) and veins dark brown; apex of hind coxa partly ivory ( Fig. 49 ); wing membrane subhyaline.

Male. Length of body 7.6 mm, of fore wing 4.3 mm, antenna with 26 segments. Similar to female but frons brownish yellow ( Fig. 59 ), vertex mainly regularly transversely striate but rugose anteriorly, temples evenly rounded in dorsal view ( Fig. 60 ), foveolation of mesopleuron, metapleuron and propodeum reduced, flattened area of hind coxa larger and coxa 3.9 × longer than wide), first tergite 8.7 × longer than wide and base of second tergite orange brown. Parameres moderately convex and setose ( Fig. 58 ).

Distribution. China (* Guangdong, * Jiangxi).

Etymology. Named “ evexus ” (Latin for “rounded at the top”), because of the rounded apex of the metasoma of the ♀.

Notes. The male of P. brevicoxalis sensu Chen et al. (2016) is transferred to this species, because of the slender first tergite (nearly 11 × as long as wide, Fig. 20 ; not the description!), the reduced dentition basally of the median tooth of the hind femur, the venation of the fore wing, and the dorsally narrow ivory streak of temple. The gradually sloping pronotum and normal hind coxa (about 3 × as long as wide) fit in with this transfer. Only the colour of the posterior part of the temple differs: rather dark brown in the paratype from Jiangxi and brown in the paratype from Guangdong.

Figures

FIGURES 43-44. Parastephanellus evexus sp. n., ♀, holotype. 43, habitus, lateral aspect; 44, first metasomal tergite, dorsal aspect.

FIGURES 45–54. Parastephanellus evexus sp. n., ♀, holotype. 45, wings; 46, head, lateral aspect; 47, mesosoma, lateral aspect; 48, mesosoma, dorsal aspect; 49, hind coxa, dorso-lateral aspect; 50, hind leg, lateral aspect; 51, base of antenna; 52, head, anterior aspect; 53, head, dorsal aspect; 54, pygidial area at apex of metasoma, dorsal aspect.

FIGURE 55. Parastephanellus evexus sp. n., ♂, topotypic paratype, habitus, lateral aspect.

FIGURES 56–61. Parastephanellus evexus sp. n., ♂, topotypic paratype. 56, wings; 57, head, lateral aspect; 58, genitalia and pygidial process, dorsal aspect; 59, head, anterior aspect; 60, head, dorsal aspect; 61, hind leg, lateral aspect.

FIGURES 18–26. Parastephanellus brevicoxalis Hong et al., ♀, holotype. 18, fore wing; 19, pronotum, lateral aspect; 20, pronotum, dorsal aspect; 21, hind coxa, dorso-lateral aspect; 22, pygidial area at apex of metasoma, dorsal aspect; 23, hind femur and tibia, lateral aspect; 24, head, anterior aspect; 25, head, dorsal aspect; 26, head, lateral aspect. From: Hong et al. (2011).