Stethynium ophelimi Huber, 2006

Huber, John T., Mendel, Zvi, Protasov, Alex & Salle, John La, 2006, Two new Australian species of Stethynium (Hymenoptera: Mymaridae), larval parasitoids of Ophelimus maskelli (Ashmead) (Hymenoptera: Eulophidae) on Eucalyptus, Journal of Natural History 40 (32 - 34), pp. 1909-1921 : 1912-1916

Stethynium ophelimi Huber , n. sp.

( Figures 1–8 )

Type material

Holotype: female (ANIC), cleared and dissected under three coverslips on slide labelled: (1) ‘‘ Australia: NSW Wagga Wagga, ex. Ophelimus maskelli leaf galls on Eucalyptus camaldulensi s’’; (2) ‘‘em. from mature larvae vii. 2005 in quarantine culture, Bet Dagan Israel, Z. Mendel’’; and (3) ‘‘ Stethynium ophelimi Huber Holotype female dorsal’’. Paratypes: 12 females and two males pinned on cards, seven females and one male on slides in Canada balsam (ANIC, BMNH, CNC, USNM).

Diagnosis

Ovipositor sheaths distinctly thickened apically and black-tipped ( Figure 4 ); ovipositor distinctly hooked at apex, and produced forward in a large loop at base of metasoma and forward inside mesosoma at least to base of mesocoxa or, in dorsal view, to at least midpoint of posterior scutellum ( Figures 3 , 4 ); fore wing with lobe of posterior margin behind venation evenly rounded ( Figure 1 ); anterior scutellum with narrow longitudinal median strip (5area between placoid sensilla, visible on slide-mounted specimens) not contrasting strongly with slightly darker lateral areas, and the lateral areas contrasting very weakly with light-coloured posterior scutellum.

The types of eight species of Australian Stethynium ( cuvieri Girault , daltoni Girault, flavinotae , latipenne Girault , lavoisieri Girault , notatum Girault , perlatipenne Girault , and vesalii Girault ) were compared directly with ophelimi . None of them is conspecific with ophelimi . Stethynium cuvieri , lavoisieri , flavinotae , and vesalii have black-tipped ovipositor sheaths ( S. latipenne is known only from males so the ovipositor sheath colour is unknown). Stethynium cuvieri has a much narrower fore wing and shorter funicle segments, S. lavoisieri has a straight ovipositor (its antennae are mostly missing except for the clava and in such poor condition they cannot be compared with S. ophelimi ), S. flavinotae has distinctly wider hind wings, and S. vesalii has shorter funicle segments, with three of them wider than long.

Description

Female. Body pale yellow to cream coloured, with lower face often having a pink tinge. Eyes and ocelli grey, sometimes with a pink tinge. Teeth of mandible, trabeculae, a diffuse streak on occiput between eye and foramen magnum, a small dot on anterior margin of axilla, and base of ovipositor dark brown. Anterior two-thirds of mesoscutum, anterior scutellum except for narrow longitudinal strip medially ( Figure 3 ), and propodeum medially darker yellow to very light brown. A vaguely triangular area medially on anterior half of gaster varying from light to dark brown and sometimes, very small, usually faint, light brown areas elsewhere on terga dorsally and laterally. Two minute dots on anterolateral corner of axilla and posterior scutellum, respectively, and apex of ovipositor sheath black. Funicle and clava dusky yellow to light brown. Wings uniformly hyaline, and venation light brown. Legs pale yellow, except for dark brown apical tarsomere of each leg.

Body length 590 (490–640, n 510). Head width 271 (245–301, n 54). Antenna ( Figure 5 ) with inner surface of scape transversely striate; funicle with all segments at least slightly longer than wide and without longitudinal sensilla; clava with six longitudinal sensilla. Length/width ratios (n 55): scape 2.77–2.86, pedicel 1.41–1.57, fl 1 1.52–2.00, fl 2 2.18–2.88, fl 3 1.96–2.67, fl 4 1.79–2.36, fl 5 1.31–1.85, fl 6 1.48–1.63, clava 2.79–3.15. Measurements length (width) (n 55 or 6): scape 69–91 (29–32), pedicel 46–55 (32–35), fl 1 24–29 (13–18), fl 2 30–44 (13–17), fl 3 28–39 (11–16), fl 4 31–37 (14–17), fl 5 27–32 (14– 22), fl 6 28–35 (20–23), clava 115–134 (39–46). Mesosoma with adnotaular seta midway between anterior and posterior margin or slightly closer to posterior margin ( Figure 3 ). Posterior scutellum length/width50.80–0.92. Mesophragma posteriorly truncate ( Figure 3 ). Fore wing length (including humeral plate) 773 (707–823, n 53), width 253 (219–282), length/width 3.07 (2.92–3.03, n 53), with discal microtrichia dense (including behind stigmal vein), with lobe of posterior margin behind venation evenly rounded ( Figure 1 ), and with longest marginal cilia 143 (123–161), just over half as long as wing width. Hind wing length 685 (632–735, n 53), width 50 (46–53), and longest marginal cilia 138 (134–145), about 2.75 times hind wing width. Metasoma with lateral margins of gaster converging in apical half to rather narrow apex ( Figure 3 ). Ovipositor sheaths distinctly thickened apically and black-tipped ( Figure 4 ), evenly curved along entire length, and not exserted; ovipositor evenly curved along its entire length, distinctly hooked at apex, exserted slightly beyond apex of gaster (in slide-mounted specimens), and produced forward in a large loop at base of metasoma and inside mesosoma at least to base of mesocoxa or, in dorsal view, at least to midpoint of posterior scutellum ( Figures 3 , 4 ).

Male. Yellow, but with much more extensive dark areas than in female, especially on mesoscutum and gaster. Dark brown areas are: a very narrow ring around each ocellus and two small spots beside upper orbit opposite lateral ocelli, a diffuse oblique streak between posterior eye margin and foramen magnum, most of midlobe of mesonotum except for posterior one-fifth to one-quarter, especially medially, a spot anteriorly on lateral lobe of mesoscutum, this joined to brown of midlobe by a lighter brown area, a large spot anteriorly and smaller one posteriorly on axilla, a small spot on mesopleuron below wing base, a slightly larger one laterally on propodeum at junction with metapleuron, and entire dorsal surface of propodeum; most of gaster dorsally and laterally (with scattered lighter brown to yellow areas), and apical gastral sterna. Anterior scutellum brown-yellow, contrasting slightly with bright yellow of posterior scutellum. Pedicel and fl 1 dusky yellow, remaining flagellomeres light grey brown. Transverse trabecula, teeth of mandible, minute spot at tegula, and apical tarsomere of each leg coloured as in female.

Body length 666 (640–691, n 52, critical point-dried specimens). Antennal measurements (length only, n 51): scape (not measurable), pedicel 40, fl 1 59, fl 2 67, fl 3 61, fl 4 65, fl 5 71, fl 6 71, fl 7 71, fl 8 72, fl 9 73, fl 10 67, fl 11 63. Length/width ratio of fl 6 2.49. Each flagellomere apparently with eight longitudinal sensilla. Genitalia with aedeagus, in lateral view, evenly rounded dorsally and parameres near aedeagal apex ( Figures 7 , 8 ).

Figures

Figures 1–3. Stethynium ophelimi sp. n., female. (1) Wings. (2) Antenna. (3) Holotype, mesosoma+metasoma, dorsal.

Figures 4–7. Stethynium ophelimi. (4) Female body, lateral. (5) Holotype, head, anterior, and antenna. (6) Male head and antenna. (7) Male mesosoma and metasoma, dorsal.

Figures 8, 9. Stethynium spp. (8) S. ophelimi, male genitalia, dorsal. (9) S. breviovipositor sp. n., wings.