Sphex latilobus, 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 : 62-63

Taxon classification Animalia Hymenoptera Sphecidae

Sphex latilobus sp. n.

Material examined.

Holotype. ♂, AUSTRALIA:WA: Bolgart, 14.12.1961, E. B. Britton & A. Douglas (BMNH). Paratypes. AUSTRALIA:WA: Bolgart, 2♂, 14.12.1961, E. B. Britton & A. Douglas (BMNH); Cervantes, 1♂, 26.12.1988, I. L. Hamer (BMNH).

The collecting localities are shown in Fig. 40C.

Diagnosis.

The males of this species (females are unknown) are easily identifiable by the bright orange coloration along the free clypeal margin, combined with the visible part of the metasomal sternum VIII modified into two completely separate lobes (Fig. 38B). Sphex bilobatus and Sphex basilicus possess similar structures, but the free clypeal margin is black in both species, and the latter also has golden pubescence on the propodeal enclosure, whereas the pubescens is silvery-white in Sphex latilobus .

Description.

Female: Unknown.

Male: Body length 18.8-24.5 mm. Body black, but the following are orange: mandible from base up to base of inner tooth, clypeus along free margin, fore- and at least partially midfemur, posterior half of tegula. Wing membrane almost completely hyaline, wing veins dark brown. Free clypeal margin straight or minimally convex. Appressed pubescence and erect setae on clypeus and frons silvery-white. Clypeus with medial glabrous stripe. Distance between hind- ocelli equal to or slightly smaller than their shortest distance to compound eyes. Pubescence on mesosoma silvery-white, on scutum denser laterally and posteriorly. Scutellum convex, with distinct medial impression. Pubescence on propodeal enclosure short, not completely concealing sculpture. Length of petiole 1.3 × length of flagellomere II. Tomentum moderately dense on metasomal tergum I, sparse on tergum II. Metasomal terga V and VI with only few bristles. Metasomal sterna II–VIII mostly glabrous. Visible part of metasomal sternum VIII forming two large, completely separated lobes (similar to Sphex bilobatus , shown in Fig. 28B; but lobes of Sphex latilobus are wider).

Variation.

Of the three examined specimens, the legs of one are almost entirely black, whereas the fore- and parts of the midfemur of the other two are orange.

Discussion.

Sphex latilobus is clearly an undescribed species. It also seems unlikely that it can be associated with one of the species based solely on females. Within the Sphex subtruncatus group, there are seven species of which males are unknown or where matching of males and females was first proposed in this study. Since most diagnostic characters of this species are suspected to be sexually dimorphic, the number of potential candidates was first narrowed down by eliminating all species where matching of males and females is well-founded ( Sphex jucundus , Sphex corporosus and Sphex pretiosus ), which leaves four species. One of them ( Sphex brevipetiolus ) has partially orange wing veins and a petiole that barely reaches the length of flagellomere II; another one ( Sphex ahasverus ) has dark setae on the clypeus, fuscous wings and golden propodeal pubescence. Of the remaining two, one ( Sphex argentatissimus ) has a clypeus with golden pubescence; the body of the other one ( Sphex flammeus ) is mostly bright orange. Thus, Sphex latilobus is unlikely to match any of the currently recognized species.

Etymology.

Latilobus is a composite of the Latin words latus (wide) and lobus (elongated projection), referring to the lobes on male sternum VIII which are similar to those of Sphex bilobatus but wider.