Euodynerus and Pseudepipona

Giordani Soika (1962 [1961]) broke up the old genus Odynerus Latreille 1802 in Australia. Before that, the very broad concept of Odynerus was employed, dating back to the only worldwide monograph of the Vespidae, de Saussure (1852–1858). Giordani Soika (1962 [1961]) transferred a number of the Australian species to the genus Pseudepipona. He employed a broad concept of Pseudepipona, which he had used for some time (Giordani Soika 1953 [1952]). This included a number of subgenera in Pseudepipona; in Australia these were Epiodynerus, Syneuodynerus Blüthgen 1951 and the nominotypical subgenus. The first two came to be treated as genera by the time of Cardale’s catalogue, leaving just the species placed in the nominotypical subgenus or unplaced by Giordani Soika (1962 [1961] in Pseudepipona, to which a few other species were added later (Giordani Soika 1977, 1993b; Borsato 2005).

Borsato (2005: 638) questioned the assignment of Australian species to Pseudepipona, stating: “The assignment of species to this genus is a provisional operation, awaiting a better knowledge of the Oriental species in general and of the Indo-Australian species in particular.” He also stated of Pseudepipona: “A cosmopolitan genus in which some Australian species were temporaneously included, having in common some characters, such as the propodeum poorly developed, the shape of the tegulae and of the first tergite.” In fact, the Australian species share no diagnostic characters with Pseudepipona, which is nowadays restricted primarily to Palearctic species. This is seen when running the Australian species through keys that include Pseudepipona in the modern sense. For example, angulatus (de Saussure 1855), pallidus Giordani Soika 1977, and succinctus (de Saussure 1853) all run to Euodynerus Dalla Torre 1904, in the key to Nearctic genera of Carpenter (2004) at a couplet that contrasts:

“Tegula variously shaped, less than two thirds as wide as long (Fig. 67); tergum I usually with transparent or translucent apical border (Fig. 68), at least laterally (sometimes narrow)” vs. “Tegula broadly rounded and expanded laterally, more than two thirds as wide as long (Fig. 69); tergum I without transparent or translucent apical border.”

The first choice leads to Euodynerus, and the second to Pseudepipona and Leucodynerus Bohart 1982. In the Australian species the tegula is evenly broadened in succinctus, but the width is not two thirds the length, and it is longer. In angulatus and pallidus the tegula is not broadened. In none of these species is there an epicnemial carina or male mandibular notch, characters distinguishing Pseudepipona in this key.

In the key to European genera of Giordani Soika (1978), these species do not key to Pseudepipona because the axillary fossa fits neither that genus nor Allodynerus Blüthgen 1938 [1937] in the last couplet. They fail at that couplet because they do not key out to Euodynerus, as there are no superior propodeal carinae. In the key to European genera of Gusenleitner (2000), they run to the subgenus Euodynerus, if considered to have an apical border on the first metasomal tergum (angulatus has laternal remnants). If not considered to have such a border (pallidus and succinctus) they key past the couplet with Pseudepipona because there are no upper propodeal carinae, and wander to Allodynerus but do not really key out. The result is the same with the key to Iranian genera of Ebrahimi & Carpenter (2008): Euodynerus or Allodynerus. In the key to Afrotropical genera of Carpenter et al. (2009) they do not run to Pseudepipona because of the tegula as well. Angulatus keys to Euodynerus if considered to have the tergal border laterally; succinctus fails because the tegula is short, but neither it nor pallidus match Antodynerus (part), the alternative at that couplet.

The key of Carpenter (2004) does not consider the apical border of the first metasomal tergum to be definitive for Euodynerus. This is because species of the genus in the Nearctic are more variable in structure than in the Palearctic. The Australian species fit better in this concept of Euodynerus than in Pseudepipona, and so they are reassigned.