Pison gracile Pulawski, 2018

Pulawski, Wojciech J., 2018, A Revision of the Wasp Genus Pison Jurine, 1808 of Australia and New Zealand, New Guinea, and the Pacific Islands (Hymenoptera: Crabronidae), Proceedings of the California Academy of Sciences 65, pp. 1-584 : 212-214

Pison gracile Pulawski , species nova

Figures 475 -481.

NAME DERIVATION.– Gracilis (neuter: gracile ) is a Latin adjective meaning slender, slim, thin; with reference to this species body shape and small size.

RECOGNITION.– Pison gracile is one of the smallest members of the genus, with body length of 5.0 mm. It has only two submarginal cells ( Fig. 477 ), the second being relatively long (length of posterior margin 1.8 × its height). Furthermore, the gaster is all black, the eyes are asetose, the tegula is finely punctate throughout, except for a narrow marginal rim, the postspiracular carina is absent, the integument is not depressed between the pronotal lobe and the episternal sulcus, and the propodeum lacks a longitudinal carina separating the side from the dorsum and the posterior surface. The male (the female is unknown) is characterized by the unusually short, obtusely angulate clypeal lamella ( Fig. 475 ), the mandible bidentate apically, and by the unusually deep apical emargination of sternum VIII ( Fig. 478 ).

DESCRIPTION.– Frons somewhat shiny, finely punctate, punctures less than one diameter apart, middle supraantennal carina absent. Occipital carina joining hypostomal carina. Gena moderately narrow in dorsal view ( Fig. 476 ). Labrum not emarginate. Anteromedian pronotal pit transversely elongate, somewhat longer than midocellar diameter. Scutum not foveate along flange, without longitudinal ridges adjacent to posterior margin; scutal punctures well defined, averaging about one diameter apart; interspaces unsculptured. Tegula enlarged, finely punctate throughout (except for narrow marginal rim). Mesopleural punctures almost contiguous. Postspiracular carina absent;

integument not depressed between pronotal lobe and episternal sulcus. Metapleural sulcus costulate between dorsal and ventral metapleural pits. Propodeum without longitudinal carina separating side from dorsum and posterior surface; dorsum obliquely ridged; side minutely punctate (impunctate along metapleuron), punctures more than one diameter apart anteriorly, less than one diameter apart posteriorly; posterior surface only punctate in dorsal half, transversely ridged and punctate in ventral half. Forewing with two submarginal cells; posterior margin of second cell 1.8 × its height ( Fig. 477 ). Posteroventral forefemoral surface microscopically punctate, punctures more than one diameter apart. Hindcoxal dorsum with outer margin obtusely carinate. Outer surface of hindtibia with only a few spines. Punctures of tergum I well defined, mostly less than one diameter apart anterior of apical depression, but some punctures more than one diameter apart mesally. Sterna punctate throughout, punctures of sternum II about two diameters apart mesally.

Setae silvery, appressed on frons, postocellar area, scutum, and tergum I, oriented ventrally on frons; completely concealing integument on clypeus except lamella, largely so on mesopleuron; on lower gena curved, shorter than midocellar diameter, appressed anteriorly, suberect near occipital carina. Apical depressions of terga with somewhat ill-defined, silvery, setal fasciae.

Head, thorax, propodeum, and gaster black; mandible yellowish except dark basally and apically. Femora black, fore- and midtibae black except reddish brown at very apex, hindtibia ferruginous on inner side, black except brown basally and apically on outer side; tarsi ferruginous.

♀.– Unknown.

♂.– Upper interocular distance equal to 0.84 × lower interocular distance; ocellocular distance equal to 1.0 × hindocellar diameter, distance between hindocelli equal to 1.7 × hindocellar diameter; eye height equal to 0.90 × distance between eye notches. Clypeal lamella unusually short,

its free margin obtusely angulate ( Fig. 475 ).

Dorsal length of flagellomere I 1.7 × apical width, of flagellomere X 1.0 × apical width.

Mandible bidentate apically ( Fig. 475 ). Sternum VIII with unusually deep apical emargination ( Fig. 478 ). Genitalia: Figs. 479 , 480.

Length 5.0 mm; head width 1.5 mm.

GEOGRAPHIC DISTRIBUTION (Fig. 481).–

Known from one locality in Western Australia.

RECORDS.– HOLOTYPE: ♂, AUSTRALIA: Western Australia: Mount Augustus National Park at

22°22.8ʹS 116°54.2ʹE, 9-22 May 2003, F.D. Parker FIGURE 481. Collecting locality of Pison gracile Pulaw- and M.E. Irwin (ANIC). ski, sp. nov.

Figures

FIGURES 475-479. Pison gracile Pulawski, sp. nov., male. (475) Clypeus and mandible; (476) Head in dorsal view; (477) Distal portion of forewing; (478) Sternum VIII (ventral view); 479 (Genitalia in dorsal view); (480) Genitalia in lateral view.