Pison areniferum Evans

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 : 60-63

Pison areniferum Evans

Figures 69 -79.

Pison areniferum Evans, 1981:422 , ♀. Holotype: ♀, Australia: Queensland: Amby (QMB), examined. – Cardale , 1985:257 (in catalog of Australian Sphecidae ).

RECOGNITION.– Pison areniferum is an all black species with three submarginal cells, the second recurrent vein contiguous with second intersubmarginal vein or nearly so, setae appressed on tergum I, and relatively large tergal punctures.

The female has well-defined psammophores on the gena, mandibular posterior margin, propleural and forecoxal outer margins, and the foretrochanteral and forefemoral venters. Like P. tomentosum , the ocellocular distance of P. areniferum is minimally larger than the distance between the hindocelli (smaller in the other black species with psammophores). Unlike P. tomentosum , the scutal punctures of P. areniferum average more than one diameter apart (rather than less than one diameter apart), the interspaces are unsculptured, shiny (rather than microsculptured, dull), punctures of the horizontal part of tergum I average more than one diameter apart (rather than less than one diameter apart), and the setae of the mesopleuron and propodeal dorsum do not completely conceal the integument (rather than completely concealing it). Also, the tegula is longer in P. areniferum than in P. tomentosum .

The male lacks conspicuous recognition features, but it may be recognized by its black body in combination with the following: many scutal punctures more than one diameter apart, setae of the propodeal dorsum short, not extending beyond the lateral carina, tergal punctures relatively large, at least sternum III impunctate or sparsely punctate apicomesally, and sternum VIII conspicuously punctate in the apical half, emarginate apically. Subsidiary recognition features are: ocellocular distance equal to 1.8-1.9 × hindocellar diameter, markedly larger than distance between hindocelli, dorsal length of flagellomere I equal to 2.1-2.2 × apical width, and propodeal side separated from dorsum and posterior surface by a longitudinal carina.

DESCRIPTION.– Frons dull, finely punctate, punctures less than one diameter apart. Occipital carina joining hypostomal carina. Labrum slightly emarginate. Anteromedian pronotal pit transversely elongate, about as long as midocellar diameter. Propleuron sparsely punctate posterolaterally in female, densely punctate in male. Scutum not foveate along flange, without longitudinal ridges adjacent to posterior margin; scutal punctures well defined, many of them more than one diameter apart, some punctures 2-3 diameters apart; interspaces unsculptured, shiny. Tegula enlarged, its outer margin nearly straight near midlength. Mesopleural punctures well defined, less than one diameter apart. Postspiracular carina absent. Metapleural sulcus not 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 with shallow median depression, with or without longitudinal carina, punctate (punctures less than one diameter apart), interspaces merging into small, irregular ridges; side punctate, not ridged, punctures (except anteriorly) less than one diameter apart; posterior surface ridged. Punctures of horizontal part of tergum I averaging more than one diameter apart. Sternum II punctate throughout, sparsely so mesally, apical depression impunctate apicomesally; at least sternum III impunctate or sparsely punctate apicomesally.

Setae silvery, appressed on frons, thorax, mid- and hindfemoral venter, and tergum I, completely concealing integument on clypeus, in female largely so on propodeal dorsum and mesopleuron; genal setae: see below.

Head, thorax, propodeum, legs, and gaster black, mandible dark reddish preapically.

♀.– Upper interocular distance equal to 0.66-0.68 × lower interocular distance; ocellocular distance equal to 1.3 × hindocellar diameter, distance between hindocelli equal to 1.1-1.2 × hindocellar diameter ( Fig. 71 ); eye height equal to 0.86-0.88 × distance between eye notches. Clypeal lamella slightly longer mesally than laterally, distance between its corners slightly greater than distance between corner and adjacent orbit ( Fig. 69 ). Dorsal length of flagellomere I 2.5-2.7 × apical width, of flagellomere IX 1.4 × apical width. Gena, mandibular posterior margin, propleural and forecoxal outer margins, and foretrochanteral and forefemoral venters with psammophores; longest setae of genal psammophore about 1.0 × greatest forefemoral width ( Fig. 72 ), of mandibular psammophore about 0.9 × greatest forefemoral width, of forefemoral psammophore about 0.8 × greatest forefemoral width ( Fig. 75); lower gena impunctate and asetose between oral fossa and psammophore. Mandible: trimmal carina with minimal incision slightly beyond midlength. Length 9.9-10.1 mm; head width 3.1-3.2 mm.

♂.– Upper interocular distance equal to 0.84-0.86 × lower interocular distance; ocellocular distance equal to 1.8-1.9 × hindocellar diameter, distance between hindocelli equal to 1.2-1.3 × hindocellar diameter; eye height equal to 0.94-0.96 × distance between eye notches. Free margin of clypeal lamella sharply angulate ( Fig. 70 ). Setae of lower gena curved, longest setae up to 1.5 × midocellar diameter. Setae of propodeal dorsum short, not extending beyond lateral carina. Dorsal length of flagellomere I 2.1-2.2 × apical width, of flagellomere X 1.1-1.2 × apical width. Sternum VIII conspicuously punctate in apical half, emarginate apically ( Fig. 76). Genitalia: Figs. 77, 78. Length 7.8-8.5 mm; head width 2.5-2.8 mm.

NESTING HABITS.– Evans (1981) observed two females nesting in a flat, sparsely vegetated sandy area near Amby, Queensland. Both females were digging nests, carrying sand from the burrow in their genal and forefemoral psammophores, flying with it about 1 m downwind and drooping it from a height of 30-40 cm; intervals between flight varied from 30 seconds to several minutes. The author did not say whether they were flying backwards, as does Gastrosericus siamensis Tsuneki in similar situations. One nest was subsequently excavated: the burrow descend- ed at about 45° angle, it was 14 cm long and reached a cell at a depth of 9 cm. It was open all the way to the cell except from a closure of sand at the entrance about 1 cm thick. A second cell was found 1.5 cm away, at a depth of 10 cm. It was closed off with sand and contained five spiders, all members of Oxyopidae : Oxyopes mundulus

75 76 77 78

L. Koch, now Oxyopes gracilipes (White) , and

O. punctatus L. Koch.

GEOGRAPHIC DISTRIBUTION (Fig. 79).–

New South Wales, Queensland, South Australia.

RECORDS.– AUSTRALIA: New South Wales:

Springs Creek 68 km SW Wilcannia at 31°44ˈS

142°41ˈE (1 ♂, ANIC). Queensland: Amby (1 ♀,

QMB, holotype of P. areniferum ). South Australia :

Chowilla Game Reserve 24 air km N Renmark at

33°58.0ʹS 140°48.8ʹE (3 ♂, CAS) and 34°00.0ʹS

140°49.4ʹE (3 ♂, CAS), Clements Gap Conservation

Park at 33°28.7ʹS 138°03.9ʹE (1 ♀, 3 ♂, CAS), Port

Clinton Conservation Park at 34°09.4ʹS 138°03.2ʹE FIGURE 79. Collecting localities of Pison areniferum Evans.

( 2 ♂, CAS) .

Figures

FIGURES 69–74. Pison areniferum Evans (69, 71-74: holotype). (69) Female clypeus and mandible; (70) Male clypeus and mandibles; (71) Female vertex; (72) Female gena in lateral view; (73) Female scutum; (74) Female tegula and adjacent scutum.