CTENOCERINAE (Shimizu, 1994)

Waichert, Cecilia, Rodriguez, Juanita, Wasbauer, Marius S., Von Dohlen, Carol D. & Pitts, James P., 2015, Molecular phylogeny and systematics of spider wasps (Hymenoptera: Pompilidae): redefining subfamily boundaries and the origin of the family, Zoological Journal of the Linnean Society 175 (2), pp. 271-287 : 280

CTENOCERINAE

This subfamily was first proposed by Haupt (1929), as Claveliinae , to separate its members from Pepsinae ; it includes two genera in the Neotropics, four in Australia, and 11 in Africa. The name was changed to Ctenocerinae ( Shimizu, 1994) , but the composition of this subfamily remained mostly stable, except for a suggestion to include Apinaspis Banks and Epipompilus ( Pitts et al., 2006) . Epipompilus is discussed below (see Pepsinae section), whereas Apinaspis is an Oriental monotypic genus ( Banks, 1938) and has characteristics similar to the Australian genera described by Evans (1972). We support the classification of Apinaspis in Pepsinae , as proposed by Shimizu (1994) and Banks (1938), until further analyses suggest otherwise. Although these African, Neotropical, and Oriental/ Australian taxa share several morphological features – a large antennal scrobe, a transverse groove on the second sternite that is usually prolonged to vertex, and a hind tibia with short spines directed straight backwards – these may be adaptations for preying on trapdoor spiders ( Evans, 1972) that were independently acquired. More information on behaviour is needed, as the natural history of these taxa remains poorly understood.

Our analyses did not recover the monophyly of Ctenocerinae . The Neotropical Lepidocnemis and the Australian Maurillus are nested within different nonctenocerine lineages with high support. The morphological similarities of these and the African ctenocerine genera must now be interpreted as convergent traits. Four Australian taxa assigned to Ctenocerinae by Evans (1972) ( Cteniziphontes Evans , Apoclavelia Evans , Maurillus , Austroclavelia Evans ) and the three genera discussed by Waichert & Pitts (2011) ( Abernessia Arlé , Lepidocnemis , Hypoferreola Ashmead ) are herein transferred to Pepsinae on the basis of the molecular phylogeny and of morphology.

The monophyly of African Ctenocerinae (clade A) was recovered in all analyses. Although support for this clade was low in the unconstrained analyses, it was high in the clock-constrained analysis. We redefine Ctenocerinae as the lineage represented by clade A, as it includes the nominal genus, Ctenocerus . The 11 Afro-tropical genera recognized by Arnold (1932b), with distribution extending into Java and India, should retain their classification as Ctenocerinae until further analyses are performed. Males of all 11 Ctenocerinae genera designated by Arnold (1932b) are distinguished from Pepsinae by having flagellum uni- or biramous, or crenulate antennae. These character states are not observed in Pepsinae . The subfamily is now recognized by (1) the metasomal sternum 2 with a distinct sharp transverse groove; (2) the mesofemur and the metafemur without subapical spine-like setae set in grooves or pits; (3) the metatibia without scale-like spines or serrate carina and with short, subequal spines directed straight backwards; and (4) the fore wing with first cubital vein (Cu1) simple at base, without any definite downward deflection; (5) the clypeus plate-like in shape; and (6) males with crenulate antennae. As far as we know, ctenocerine spider wasps prey on trap-door spiders.