Systematics and convergent evolution in three Australian genera of Pepsinae spider wasps (Hymenoptera: Pompilidae)

Abstract

We treat the Australian spider wasp 'Ctenocerini', revising the systematics of Maurillus Smith, adding a new species Maurillus argenticapitis Pitts & Shimizu sp. nov. and describing two new monobasic genera Maurilloides Pitts & Shimizu gen. nov. based on Maurilloides nigrisoma Pitts & Shimizu sp. nov. and Evansiclavelia Pitts, Rodriguez & Shimizu gen. nov. based on Evansiclavelia poecilopteryx Pitts, Rodriguez & Shimizu sp. nov.We further discuss the phylogenetic position of Maurillus and the convergent evolution of the modification in head and pronotal structures occurring in the above three genera, as well as in pompilids from other subfamilies, that parasitise trapdoor spiders.

First records of the spider wasps Ctenocerus Dahlbom and Paraclavelia Haupt from Asia, with discussions on the systematics of Ctenocerinae (Hymenoptera: Pompilidae)

“…The pronotal structure of Entomobora is, however, different from that of Paraclavelia, Ctenocerus and Psorthaspis: the dorsum is truncate anteriorly with a deep, almost vertical declivity; hence, the neck region lies deeply below the level of the pronotal dorsum (Fig. 11B) (Shimizu et al 2021). Such Entomobora-like modifications (the Entomobora-morphotype) is also found in the Australian Austroclavelia Evans, 1972 (Fig.…”

“…When the wasps attempt to open burrow lids, the spider hooks its first pair of legs onto the edge of the flap opposite its hinge and maintains its closure (Janvier 1930). Thus, the wasps face physical resistance before opening the burrow lid; hence the lid opening is of critical importance for the wasps (Iwata 1976;Shimizu et al 2021). This seems to have resulted in a convergent evolution of the head and pronotal specialization in the parasitoid Pompilidae preying on trapdoor spiders (Shimizu et al 2021).…”

“…Thus, the wasps face physical resistance before opening the burrow lid; hence the lid opening is of critical importance for the wasps (Iwata 1976;Shimizu et al 2021). This seems to have resulted in a convergent evolution of the head and pronotal specialization in the parasitoid Pompilidae preying on trapdoor spiders (Shimizu et al 2021). In fact, another pompiline genus, Entomobora, which is known to parasitize trapdoor spiders of the genera Nemesia Audouin, 1826 (Nemesiidae), Ummidia Thorell, 1875 (Halonoproctidae) and Cteniza Latreille, 1829 (Ctenizidae) (Ferton 1897(Ferton , 1901(Ferton , 1905Gros 1983Gros , 2004; see also Shimizu et al 2021), bears the highly modified head and pronotum very similar to those of Paraclavelia, Ctenocerus, and Psorthaspis.…”

“…This seems to have resulted in a convergent evolution of the head and pronotal specialization in the parasitoid Pompilidae preying on trapdoor spiders (Shimizu et al 2021). In fact, another pompiline genus, Entomobora, which is known to parasitize trapdoor spiders of the genera Nemesia Audouin, 1826 (Nemesiidae), Ummidia Thorell, 1875 (Halonoproctidae) and Cteniza Latreille, 1829 (Ctenizidae) (Ferton 1897(Ferton , 1901(Ferton , 1905Gros 1983Gros , 2004; see also Shimizu et al 2021), bears the highly modified head and pronotum very similar to those of Paraclavelia, Ctenocerus, and Psorthaspis. The characters shared by Entomobora and the three genera are: (1) the clypeus narrower than LID, flattened with a basal or basilateral depressions that are continuous to the lower frontal depression (Fig.…”