Pison argyrotrichum 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 : 76

Pison argyrotrichum Pulawski , species nova

Figures 99 -107.

NAME DERIVATION.– Argyrotrichum , a composite of two Greek words: ὰργυρός, silver, and θρίχΙνΟς, of hair, from θρίξ, a hair; with reference to the silvery scutal setae of this species.

RECOGNITION.– Pison argyrotrichum , known from one male only, is an all black species, with the setae silvery on the scutum and erect on tergum I, and sterna III and IV with a few, sparse punctures on each side of midline. It is further characterized by the following character combination: mesopleural punctures less than one diameter apart; punctures of upper frons well defined, about 0.1-0.2 × midocellar diameter; posterior mandibular margin gradually curving toward apex (not step-like); inner mandibular margin simple (not tridentate or bidentate apically); tergal setae silvery; dorsal length of flagellomere I 2.3 × apical width. The species closely resembles P. rarum (known from the female sex only), but differs as follows: in P. argyrotrichum , several admedian punctures of the scutum anteriorly are more than one diameter apart ( Fig. 102 ), and the punctures on the scutellum are about as sparse as most punctures on the scutum, whereas in P. rarum the punctures in the anterior half of the scutum are no more than one diameter apart, and the punctures of the scutellum are sparser than most punctures on the scutum.

DESCRIPTION.– Frons dull, with well defined punctures that are less than one diameter apart. Occipital carina joining hypostomal carina. Gena relatively narrow in dorsal view ( Fig. 100 ). Labrum not emarginate. Anteromedian pronotal pit transversely elongate, about 3.0 × as long as midocellar diameter. Scutum not foveate along flange, with short, irregular longitudinal ridges adjacent to posterior margin; scutal punctures well defined, mostly less than one diameter apart, but several admedian punctures anteriorly more than one diameter apart ( Fig.102 ). Scutellum with punctures about as sparse as those on scutum. Tegula somewhat enlarged. Mesopleural punctures well defined, less than one diameter apart. Postspiracular carina present, about 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 irregularly, obliquely ridged, punctate between ridges; side ridged, punctate between ridges; posterior surface ridged, with several ridges radiating up from transverse carina just above gastropropodeal articulation. Posteroventral forefemoral surface with well defined punctures; several punctures more than one diameter apart. Punctures of tergum I well defined, about 1-2 diameters apart on horizontal portion mesally anterior of apical depression, averaging more than one diameter apart on basal declivity. Sternum II sparsely punctate apicomesally; sterna III and IV with a few, fine punctures on each side of midline, denser laterally ( Fig. 103 ).

Setae silvery, erect on postocellar area, thorax, forecoxal venter, femoral venters, and tergum I; on lower gena sinuous, up to 2.5 × midocellar diameter; in single specimen examined clypeal setae missing mesally, but concealing integument laterally. Apical depressions of terga with silvery, setal fasciae.

Body all black.

♀.– Unknown.

♂.– Upper interocular distance equal to 0.76 × lower interocular distance; ocellocular distance equal to 1.2 × hindocellar diameter, distance between hindocelli equal to 1.1 × hindocellar diameter; eye height equal to 0.96 × distance between eye notches. Free margin of clypeal lamella roundly arcuate, somewhat prominent ( Fig. 99 ). Flagellomeres III and IV concave basoventrally, convex apicoventrally ( Fig. 101 ). Dorsal length of flagellomere I 2.3 × apical width, of flagellomere X 1.1 × apical width. Apical margin of sternum VIII minimally, broadly emarginate, almost straight ( Fig. 104 ). Genitalia: Figs. 105, 106 . Length 8.0 mm; head width 2.5 mm.

Figures

FIGURES 99–104. Pison argyrotrichum Pulawski, sp. nov., male. (99) Clypeus and mandibles; (100) Head in dorsal view; (101) Flagellum showing emarginate ventrally flagellomeres III and IV; (102) Tegula and adjacent scutum; (103) Sterna III-V in slightly oblique view; (104) Sternum VIII (ventral surface).

FIGURES 105–106. Pison argyrotrichum Pulawski, sp. nov., male. (105) Genitalia in dorsal view; (106) Genitalia in lateral view. FIGURE 107. Collecting locality of Pison argyrotrichum Pulawski, sp. nov.