Neostethynium americanum Huber, 2020

Huber, John T., Read, Jennifer D. & Triapitsyn, Serguei V., 2020, Illustrated key to genera and catalogue of Mymaridae (Hymenoptera) in America north of Mexico, Zootaxa 4773 (3), pp. 1-411 : 256

Neostethynium americanum Huber , sp. n.

( Figs 659–676 )

Type material. Holotype ♀ ( CNC), dissected under 4 coverslips on slide ( Fig. 670 ) labelled: 1. “ Holotype Neostethynium americanum Huber ♀ dorsal”. 2. “ USA: SC, Pickens Co., Clemson , Cherry’s Crossing, 250m, 26.v- 29.vi.1987, oak woodland along lake shore, FIT”.

Paratypes. 97 ♀, 1 ♂. USA. GA: Clarke Co., Athens , Oconee Forest Park, 11-12.vii.1987, G. Gibson (1 ♀, CNC) . SC: same data as holotype (45 ♀, 1 ♂, CNC, NHMUK, UCRC, USNM) , same data as holotype but 5.vi- 7.vii.1987 (42 ♀, CNC, NHMUK, UCRC) , same data as holotype but 8-20.vii.1987 (1 ♀, CNC) . VA: Wa rr en Co. , Shenandoah Nat. Park, Compton Gap, 800m, vii- 23.viii.1987, MT, CNC Hym. Team (1 ♀, CNC) .

Diagnosis. Neostethynium americanum is distinguished from N. stenopterum (Ogloblin) , the only other described Neostethynium species, by the following combination: scutellar seta much closer to lateral margin of scutellum than to campaniform sensillum ( Fig. 666 ) (midway between in N. stenopterum ); mandible short, but still longer than its basal width ( Fig. 662 ) (shorter in N. stenopterum , the mandible rudimentary); fu 2 and fu 6 relatively longer than wide ( Fig. 665 ) (relatively shorter in N. stenopterum ). Male with dorsal tooth an apically rounded and serrate lobe distinctly different from the 2 ventral teeth ( Fig. 672 ) (dorsal tooth same as 2 ventral teeth in N. stenopterum ).

Description. Female. Body length 455–605 (n=10), 564–626 (n=3, slide mounts). Colour. Body light brown except base of ovipositor dark reddish brown or almost black; eye and ocelli reddish; scape and pedicel yellow, flagellum brown; legs except apical tarsomeres yellowish except femora and tibiae with light brown areas; wings almost uniformly hyaline ( Fig. 664 ). Head width (n=5, including holotype) 171–186. Mandibles short but distinct, when closed their apices not meeting medially ( Fig. 660, 661 ). Antenna. Funicle segments without mps, claval segments each with 1 mps, apex of clava with short, indistinct nipple ( Fig. 665 ); length/width measurements (ratios) (n=5) are: scape 48–62/18–21 (2.37–3.21), pedicel 40–42/20 (2.00–2.10), fu 1 25–29/9–11 (2.37–3.04), fu 2 39– 42/10–12 (3.33–3.92), fu 3 33–38/10–11 (3.07–3.69), fu 4 35–36/11–12 (3.03–3.26), fu 5 30–34/10–12 (2.71–3.00), fu 6 28–33/12–14 (2.06–2.48), clava 88–104/20–25 (3.79–5.29). Wings. Fore wing with two uneven longitudinal rows of microtrichia beginning well beyond apex of venation and a few behind apex of venation; hind wing without median rows of microtrichia ( Fig. 664 ). Fore wing length (n=7) 553–586, width 64–70, length/width 8.16–8.88, longest marginal setae 126–151; hind wing length 550–579, width 17–30, longest marginal setae 82–107. Ovipositor length 154–166 (n=6), 0.71–0.80× as long as metatibia length (202–228).

Male. Similar to female except for head and antenna ( Fig. 674 ). Head width 189 (n=1); mandibles large, their apices crossing each other medially, with 3 teeth, the two ventral ones pointed and equal in size, the dorsal tooth a rounded finely serrate lobe ( Figs 672, 673 ). Antenna. fl 1 and fl 2 apparently each with 2 mps, fl 3 –fl 10 apparently each with 3 or 4 mps, fl 11 apparently with 1 mps (difficult to see any of them); length/width measurements (ratios) (n=1) are: scape 62/22 (2.77), pedicel 40/23 (1.75), fl 1 30/16 (1.87), fl 2 27/16 (1.72), fl 3 33/17 (1.95), fl 4 34/19 (1.83), fl 5 34/18 (1.89), fl 6 36/20 (1.75), fl 7 34/18 (1.83), fl 8 36–18 (1.93), fl 9 36/20 (1.78), fl 10 36/16 (2.17), fl 11 37/16 (2.24). Genitalia as in Fig. 676 .

Derivation of species name. The species is named after the country it occurs in ( USA, commonly referred to as America).

Distribution. USA: GA, SC, VA.

Figures

FIGURE 659. Neostethynium americanum Huber, paratype habitus. USA, South Carolina, Pickens Co., Clemson, Cherry’s Crossing, 26.v–29.vi.1987, near lakeshore, J. Johnson. Scale bar=500 μm.

FIGURES 660–664. Neostethynium americanum Huber, paratype head except 664. 660, anterior; 661; posterior; 662a, lateral; 662b, lateral (internal) showing ocular apodeme; 663a, dorsal; 663b, mouthparts; 664, wings. Scale bars=100 μm.

FIGURES 665–667. Neostethynium americanum Huber, paratype. 665, antenna; 666, mesosoma, dorsal; 667, mesosoma, lateral. Scale bars=100 μm.

FIGURES 668–671. Neostethynium americanum Huber, paratype except 670. 668, metasoma, dorsal; 669, metasoma, showing genitalia through gaster; 670, holotype slide; 671, metasoma, lateral. Scale bars=100 μm.

FIGURES 672–676. Neostethynium americanum Huber, paratype male. 672, head, anterior; 673, head, posterior; 674, antenna; 675, metasoma, dorsal; 676, metasoma showing genitalia through gaster. Scale bars=100 μm.