Sphex brevipetiolus, Doerfel, Thorleif H. & Ohl, Michael, 2015

Doerfel, Thorleif H. & Ohl, Michael, 2015, A revision of the Australian digger wasps in the genus Sphex (Hymenoptera, Sphecidae), ZooKeys 521, pp. 1-104 : 47

Taxon classification Animalia Hymenoptera Sphecidae

Sphex brevipetiolus sp. n.

Material examined.

Holotype. ♀, AUSTRALIA:WA: 3 miles N of Moora, 05.01.1966, J. A. Grant (BMNH).

The collecting locality is shown in Fig. 35B.

Diagnosis.

Sphex brevipetiolus (of which only the female is known) is one of the few species in the Sphex subtruncatus group with a petiole shorter than flagellomere II. It differs from females of Sphex ermineus and Sphex corporosus , which are similar, in having bright orange veins near the wing base and a markedly convex scutellum with a distinctly developed impression medially. Sphex ermineus has black wing veins, and the scutellum of Sphex corporosus is flatter and often lacks an impression.

Description.

Female: Body length 31.6 mm. Body black. Wing membrane hyaline, with fuscous spot beyond marginal cell. Wing veins orange, darker near apex. Forebasitarsal rake with nine long spines. Free clypeal margin with two small lobes medially, distance between them less than 1/8 length of flagellomere II. Appressed pubescence and erect setae on clypeus and frons silvery-white. Clypeus with medial glabrous stripe. Distance between hind- ocelli 0.8 × their shortest distance to compound eyes. Pubescence on collar, scutum, metanotum and propodeum silvery-white, on scutum denser laterally. Scutellum convex, with medial impression. Pubescence on propodeal enclosure not concealing sculpture. Length of petiole 0.8 × length of flagellomere II. Tomentum moderately dense on metasomal tergum I, slightly denser on tergum II.

Male: Unknown.

Discussion.

In the Sphex subtruncatus group, there are eight species of which females are yet unknown or where matching of males and females was first proposed in this study. Sphex brevipetiolus can theoretically be the female of one of them. Of these, only three have wing veins that are not uniformly dark. One of them ( Sphex flammeus ) has a bright orange metasoma and largely orange legs. The second one ( Sphex pretiosus ) has a sharp transition between golden and silvery pubescence on the propodeum and, like the former, a petiole that is considerably longer than flagellomere II. Finally, the reasons for ruling out Sphex corporosus are given in the respective discussion.

Etymology.

Brevipetiolus is a composite of the Latin adjective brevis (short) and the noun petiolus (stem), referring to the short petiole of this species.