Pseudalastor, Giordani Soika, 1962

Carpenter, James M. & Brown, Graham R., 2021, Catalogue of the Australian Eumeninae (Hymenoptera: Vespidae), Zootaxa 4919 (1), pp. 1-68 : 7

Pseudalastor and Australodynerus

Borsato (2003: 543) considered Pseudalastor Giordani Soika (1962 [1961] closely related to Australodynerus Giordani Soika (1962 [1961]): “The genus Pseudalstor Giordani Soika close to Australodynerus G.S. should comprise a group of well homogeneous species. Really, several characters, above all in the shape of propodeum and thorax, are related in both above mentioned genera.”

He specified ( Borsato 2003: 543): “If one takes into consideration the propodeum, the shape of the second sternite, and the presence of a transverse oval plaque, the species attributed to the genus Australodynerus G. S. would find a better placement inside the genus Pseudalastor G. S.”

The transverse oval plaque refers to a transversely oval area on the vertex of the female, densely setose, in which the cephalic foveae are located. This plaque is wider in Pseudalastor than in any other Australian taxa, being wider than the ocellar triangle. In contrast, the second metasomal sternum varies in structure in Pseudalastor , while the propodeum varies in Australodynerus .

Later, in describing the species carpenteri in Pseudalastor, Borsato (2003: 544) stated: “I arbitrarily atrribute importance to the wide oval plaque on the head vertex and I describe the new species assigning it temporarily to the genus Pseudalastor G. S.” Thus, the plaque really is diagnostic in Pseudalastor . Borsato (2003: 543) said of carpenteri : “a species almost identical in shape and colouration to A. peculiaris , but with the clypeus tridentate, makes the borders between these two genera thinner and weaker.” This leads rather to questioning the generic placement of Australodynerus peculiaris Borsato 1994 , which has a female cephalic plaque wider than the ocellar trangle, as noted in the original description. We are therefore transferring that species to Pseudalastor . Australodynerus aurantiacus Borsato 1994 , was also described with a wide female cephalic plaque, and so we are also transferring that species to Pseudalastor .

It may be added that Borsato (2003: 547) stated of Pseudalastor superbus : “The particular length of the body, the big transverse oval plaque on the vertex of the head, and the shape of the 2nd sternite would lead me to consider this species belonging to the genus Flammodynerus G. S.” To the contrary, Flammodynerus has a cephalic plaque narrower than the ocellar triangle.

Other Considerations