Pison triodon 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 : 474-477

Pison triodon Pulawski , species nova

Figures 1152-1158.

NAME DERIVATION.– Triodon is derived from two Greek words: τρία, three, and ὀδούς, a tooth; with reference to the tridentate female clypeus of this species.

RECOGNITION.– Pison triodon is an all black species (mandible ferruginous except basally and apically, flagellum brown to yellowish brown ventrally, apical tarsomere brown or ferruginous), with three submarginal cells, the second recurrent vein interstitial with the second intersubmarginal vein or nearly so, and setae silvery, appressed on tergum I.

The female is characterized by the lower gena impunctate and glabrous on each side of the oral fossa and by the presence of a short psammophore on the mandible, lower gena (Fig. 1154), and forefemur. It differs from similar species in having an obtusely tridentate clypeal lamella (Fig. 1152). Like P. setiferum , its mid- and hindtibial spurs are whitish rather than black or brown (ferruginous in P. ciliatum ).

The male has the apical margin of sternum VIII rounded (Fig. 1155), without apicolateral corner or any specialized structure on its surface. It is furthermore characterized by the free margin of the clypeal lamella slightly concave on each side of the midpoint and with a slightly, obtusely prominent lateral corner (Fig. 1153), many punctures on the scutal disk more than one diameter apart, the punctures of sterna II and III many diameters apart. The whitish mid- and hindtibial spurs are a subsidiary recognition feature. Unlike P. parvum , the setae of the lower gena are suberect, slightly sinuous, as long as midocellar diameter (rather than curved, subappressed, shorter than midocellar diameter) and sternum II impunctate apicomesally (rather than punctate throughout).

DESCRIPTION.– Frons dull, superficially punctate, punctures nearly compressed against each other in female, less than one diameter apart in male. Gena narrow in dorsal view. Labrum not emarginate. Anteromedian pronotal pit transversely elongate, about as long as midocellar diameter. Scutum not foveate along flange, without longitudinal ridges adjacent to posterior margin; scutal punctures well defined, either less than one diameter apart or many punctures on disk averaging about one diameter apart. Tegula enlarged. Mesopleural punctures largely concealed by vestiture in fresh specimens, less than one diameter apart in female, averaging about one diameter apart in male. Postspiracular carina present, as long as midocellar diameter. Metapleural sulcus costulate between dorsal and ventral metapleural pits. Propodeum with irregular longitudinal carina separating side from dorsum and posterior surface and extending from gastral socket area toward spiracle; dorsum densely punctate (interspaces linear) or obliquely ridged (partly or all), punctate between ridges; side ridged, punctate between ridges except impunctate anteriorly; posterior surface transversely ridged except laterally. Hindcoxal dorsum with outer margin either obtusely or sharply carinate. Punctures of tergum I less than one diameter apart on horizontal part in female, about one diameter apart in male. Sterna II-IV minutely punctate, punctures sparse, many diameters apart.

Setae silvery, appressed on scutum (a few setae may be suberect), and tergum I; frontal setae oriented ventrally in ventral half, oriented dorsally in dorsal half, oriented radially around midocellus; largely concealing integument on clypeus; see below for setae of lower gena. Apical depressions of terga with silvery, setal fasciae.

Head, thorax, propodeum, and gaster black, mandible ferruginous except basally and apically; flagellum brown to yellowish brown ventrally. Legs black, apical tarsomere brown or ferruginous; mid- and hindtibial spurs whitish.

♀.– Upper interocular distance equal to 0.70-0.72 × lower interocular distance; ocellocular distance equal to 0.7-0.9 × hindocellar diameter, distance between hindocelli equal to 1.4-1.7 × hindocellar diameter; eye height equal to 0.88-0.92 × distance between eye notches. Free margin of clypeal lamella obtusely tridentate (Fig. 1152). Dorsal length of flagellomere I 1.8-1.9 × apical width, of flagellomere IX 1.0-1.3 × apical width. Lower gena (Fig. 1154), mandibular posterior margin, and forefemoral venter with psammophores (longest setae of genal, mandibular, and forefemoral psammophores about 0.5 ×, 0.5-0.7 ×, and 0.3-0.4 ×, respectively, of greatest forefemoral width); lower gena impunctate and asetose between oral fossa and psammophore. Mandible: trimmal carina with small incision at about midlength. Length 5.9-6.8 mm; head width 1.8-2.2 mm.

♂.– Upper interocular distance equal to 0.86 × lower interocular distance; ocellocular distance equal to 1.1 × hindocellar diameter, distance between hindocelli equal to 1.5 × hindocellar diameter; eye height equal to 0.96 × distance between eye notches. Free margin of clypeal lamella slightly concave on each side of midpoint, with slightly, obtusely prominent lateral corner (Fig. 1153). Dorsal length of flagellomere I 1.8 × apical width, of flagellomere X 0.8 × apical width; flagellomeres III-VI insignificantly convex ventrally. Sternum VIII rounded apically, without apicolateral corner (Fig. 1155). Genitalia: Figs. 1156, 1157. Length 6.6 mm; head width 2.0 mm.

GEOGRAPHIC DISTRIBUTION (Fig. 1158).– Northwestern part of Northern Territory.

RECORDS.– HOLOTYPE: ♀, AUSTRALIA: Northern Territory: Victoria Highway 38.5 km SW Timber Creek at 15°42ʹ40ʺS 130°07ʹ48ʺE, 15-19 June 2001, M.E. Irwin, F.D. Parker, and C. Lambkin ( ANIC).

PARATYPES: AUSTRALIA: Northern Territory: Keep River National Park at 15°45ʹ30ʺS 129°06ʹ28ʺE, 6-9 June 2001, E. Irwin, F.D. Parker, and C. Lambkin (1 ♀, CAS), at 15°47ʹ49ʺS 129°06ʹ31ʺE, 6-8 June 2001, M.E. Irwin, F.D. Parker, and C. Lambkin (2 ♀,

CAS), and at 15°54ʹ55ʺS 129°04ʹ11ʺE, 31 May –

3 June 2001, T. Weir, K. Pullen, P. Bouchard (1 ♀,

ANIC); Sterling Creek crossing on Buntine Highway 91 km SW Kalkarinji at 17°40ʹ36ʺS

130°00ʹ24ʺE, 11-17 June 2001, M.E. Irwin, F.D.

Parker, and C. Lambkin (1 ♂, CAS); Victoria Highway 38.5 km SW Timber Creek at 15°42ʹ40ʺS

130°07ʹ48ʺE, M.E. Irwin, F.D. Parker, and C. Lambkin, 6-13 June 2021 (2 ♀, CAS), 13-19 June 201

(4 ♀, CAS), and 15-19 June 2001 (5 ♀, ANIC; 5 ♀,

CAS).