Pergaphaga leaski Wharton, 2010

Wharton, Robert, Cammack, Jonathan & Mullins, Patricia, 2010, A revision of the westwoodiine genus Pergaphaga (Hymenoptera, Ichneumonidae, Ctenopelmatinae), ZooKeys 37 (37), pp. 35-68 : 63-64

Pergaphaga leaski Wharton , sp.n.

urn:lsid:zoobank.org:act:20C7D974-B61E-4870-879A-EA0F7D055435

Figs 7, 11, 19, 26, 34, 39, 43

Type locality. Australia, Victoria, Ballarat, - 37.567S, 143.850E

Type material. Holotype. Female ( BMNH), with handwritten labels as follows: “Bred. from. larvae./ 25-iv-1959 / No. 537. P.” “ Australia./ Victoria./ Ballarat./ M.F. Leask. ” “Glen. Park. S.F./ at. Wayne’s./ Sawfly/larvae.” “adult.recog. Leask./ pergagrapta ♁/gravenhorstii/ Westwood.1880” “ Pergaphaga / det. I.D. Gauld, 1984 ” [partially printed] “ HOLOTYPE / Pergaphaga / leaski/ Wharton” [red, handwritten]

Paratypes: 2 females, same data as holotype ( BMNH) ; 1 female, 1 male, same data except 1.VII.1959 and without Glen Park label. All paratypes have an additional British Museum 1959–460 accession label .

Description. Female (Figs 7, 11). Length of body (exclusive of antenna) 10.7mm; of fore wing 10.2–11.9mm; of antenna 12.5–14.8mm.

Head. Clypeus (Fig. 19) 2.7 times as broad as long; weakly and evenly convex in profile, very weakly thickened at lateral margin; ventral margin broadly truncate, slightly thickened; surface punctate on weakly shagreened background, punctures separated from one another by their diameter; epistomal sulcus distinct. Malar space 0.45–0.50 times basal width of mandible, granular-matt. Gena as in P. iangauldi , distinctly punctate. Face (Fig. 19) deeply and densely punctate laterally, granular rugose medially, surface distinctly undulating as in P. iangauldi . Frons lacking distinctly elevated interantennal flange of P. nigra (Figs 23, 26), with a low short, weak, median carina; frons distinctly elevated adjacent eye, elevated area punctate, frons otherwise flat; surface polished immediately behind scape, densely granular on flat portion between ocellar field and eye. Antenna with 39–41 flagellomeres; first flagellomere 1.2 times longer than second, 3.3–3.6 times longer than wide, second flagellomere 2.8–3.0 times longer than wide, tenth 2.0–2.6 times longer than wide; tyloid of first flagellomere large, oval, extending 0.35–0.40 length of first flagellomere.

Mesosoma . Pronotum punctate laterally on shagreened background, punctation slightly less dense than in P. nigra and P. iangauldi , punctures separated by 1.0–1.5 times their diameter. Mesopleural depression more sparsely punctate ventrally than in P. nigra and P. iangauldi , punctures widely separated, not coalescing medially to form either strigose or rugulose sculpture; rounded lobe forming anterodorsal margin of mesopleural depression with similarly large, well-spaced punctures. Scutellum slightly more finely punctate than in P. nigra and P. iangauldi . Posteromedian plate of metanotum polished, varying from distinctly punctate anteriorly to sparsely, indistinctly punctate throughout. Metapleuron medially finely granular-matt and sometimes weakly punctate. Propodeum weakly convex in profile, anterior and posterior fields not differentiated; base of propodeum, on either side of median depression, smooth, polished (Fig. 34); pleural carina incomplete: sharply defined anteriorly, extending to propodeal spiracle, usually absent posteriorly; anterior transverse carina not distinguishable from surrounding narrow band of transverse ridges; distinctly arched lateral portion of posterior transverse carina and posterior portion of lateral longitudinal carina forming apicolateral area similar to but usually weaker than in P. iangauldi , junction of lateral longitudinal and posterior transverse carinae not tuberculate. Hind basitarsus 10.6–12.0 times longer than wide. Fore wing areolet very small, triangular, petiolate above, the stalk equal to length and longer than width of areolet (Fig. 39); 2m-cu arising near but distad middle. Hind wing with 1st abscissa of Cu1 0.75–0.85 times length of cu-a; cu-a reclivous.

Metasoma. Petiole with S1 extending to level of spiracle. Apical 0.3–0.4 of postpetiole (posteriad spiracle) sparsely punctate and setose. T2 mostly bare and polished, with a few scattered punctures and a patch of short setae posterolaterally. T3 and T4 extensively setose and very faintly punctate, T4 somewhat uniformly setose, T3 decidedly less so, especially posteromedially.

Color (Figs 7, 11, 19, 43). Mostly black, antenna dark brown to black; mandible (except dark apical teeth), broad orbital bands on face extending onto anterior part of frons, at least lateral corners of clypeus, lower gena, tibia and tarsi of fore and mid legs, and tarsomeres 2–4 of hind legs bright yellow; tegula, trochanters, trochantelli, and femora of fore and mid legs darker yellow; trochanter, trochantellus, femur, and apical tarsomere of hind leg orange, hind tibia orange brown basally becoming orange over distal 0.25, hind basitarsus orange brown basally, yellow over distal 0.25; postpetiole, except along lateral margins, and entire gaster orange; middle of gena with small, dark reddish brown spot posteriorly.

Male. About as in female, but only known specimen in poor condition.

Distribution and biology. Known from a single series of specimens reared from Pergagrapta gravenhorstii (Westwood) in Ballarat , Victoria.

Diagnosis. This species is readily recognized by the combination of orange gaster and entirely dark antenna. As in the larger-bodied P. iangauldi , an elevated median flange is absent on the frons. As noted above, P. iangauldi also has a more heavily sculptured mesopleuron than P. leaski .

Remarks. There is some minor variation in color in the type series. The clypeus is mostly reddish brown in the holotype but extensively yellow in the paratypes, with a small reddish brown spot dorsomedially.

The species is named for Maurice Leask, who reared numerous westwoodiines from various pergid sawflies, including all of the members of the type series. This species is referred to as Pergaphaga sp. 1 in Gauld (1984).