POMPILINAE (Wahis, 1981)

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 : 281-282

POMPILINAE

Pompilinae has been historically the most diverse group in Pompilidae . Although several diagnostic character states apparently define this group, its classification and taxonomic composition have been a continuing topic of discussion for systematists. Notocyphus and Chirodamus were previously included in Pompilinae ( Pitts et al., 2006) . Epipompilus was previously classified as Pompilinae ( Harris, 1987) , until it was elevated to Epipompilinae ( Shimizu, 1994), and then transferred to Ctenocerinae ( Pitts et al., 2006) . Cordyloscelis Arnold was also considered a member of Pompilinae ( Arnold, 1935) .

Sericopompilus Howard + Priochilus Fabricius + Balboana form an early-branching lineage (clades G and H) within the pompilines sensu lato. Although the placement of this lineage with respect to clade I (remaining Pompilinae ) was uncertain, clade I is a wellsupported, separate lineage ( Fig. 1). The taxa of clades G and H have unique morphology and behaviour amongst the Pompilinae , which would justify elevating both clades to subfamily level. However, we abstain from defining these as different subfamilies until further data are available; instead, we propose the tribes Sericopompilini and Priochilini . It is possible that future studies will provide the necessary support to consid- er these taxa as subfamilies with unique evolutionary histories.

Our analyses recovered a lineage (clade I) composed of most of the genera traditionally placed in Pompilinae . The large pompiline lineage excluded several contentious genera, namely Cordyloscelis , Chirodamus , Notocyphus , and Epipompilus . Our analyses placed Chirodamus and Cordyloscelis within Pepsinae . Several clades within the large pompiline lineage received high support and could be good candidates for tribal revisions.

Pompilinae are herein characterized by: (1) the metatibia with apical spine-like setae long, of irregular lengths and spacing, the setae distinctly splayed (except in species of Balboana and some species of Priochilus ); (2) the fore wing with vein Cul usually distinctly deflected downward at base [second discal cell (2D) with a posterior ‘pocket’] (except in species of Balboana and Priochilus ); (3) the mesofemur and metafemur usually with one or more distinct subapical dorsal spine-like setae set in grooves or pits, but rarely without such setae; and (4) tarsomere 5 (last tarsal segment of hind leg) with ventral preapical setae often forming a distinct median row, but the setae sometimes absent. Not all pompilines have spiny legs. Some have smooth legs that could mislead subfamilial classification, for example, in the African genus Kyphopompilus Arnold and the genera of Aporini . Nesting behaviour within this group is variable and contains most of the states observed in Pompilidae , such as nesting in pre-existing cavities, using the spider’s burrow, digging a burrow on the ground, and kleptoparasitism.

Sericopompilini (new rank)

Three species of Sericopompilus are found in North America and one in Australia ( Evans, 1950). Evans (1950) suggested that the disjunct distribution and lack of morphological specialization indicate that Sericopompilus is an old lineage within Pompilinae . Evans (1966) further proposed, without formal cladistic analysis, that Sericopompilus was related to Poecilopompilus Howard and Episyron Schiödte , but had retained ‘ancestral conditions’ compared with these genera. Shimizu (1994) placed Sericopompilus as sister to ( Austrochares Banks + Parabatozonus Yasumatsu + Poecilopompilus + Batozonellus Arnold + Episyron Schiødte ). Later, Shimizu (1997) concluded that Agenioideus Ashmead should be considered sister to Sericopompilus , a conclusion supported by Pitts et al. (2006). Our analyses suggest that Sericopompilus is possibly an old lineage within this subfamily (clade G), as suggested by Evans (1950).

Sericopompilus have slender bodies, long wings ( Wasbauer, 1995) and are distinguished from Pompilinae by having the apical tarsal segments without spines beneath and all claws of both sexes dentate ( Evans, 1966). Little is known about hunting and nest behaviour of Sericopompilus but Sericopompilus apicalis (Say) has been observed nesting in holes in the ground ( Evans, 1950).

Priochilini (reinstated)

Priochilus and Balboana are morphologically enigmatic genera; consequently, their classification has varied according to author. Both genera exhibit a Neotropical distribution. Two aspects of their characteristic morphology have also been historically associated with pepsines and ctenocerines – a sharp transverse groove on the second metasomal sternite and the fore wing with vein Cu1 not deflected downward at base. Another character state is shared with pompilines – the metatibia with apical spine-like setae of irregular lengths and spacing. This morphological similarity has generated conflicting classifications. Both genera were classified in Cryptocheilinae ( Pepsinae ) by Banks (1944, 1946). Haupt (1959) included Priochilus in Macromerinae (currently Ageniellini ( Pepsinae )). Both Priochilus and Ageniellini species have slender bodies, a petiolate metasoma, and build nests using mud. Evans (1966) considered the morphological features as convergences associated with the unusual mud-nesting behaviour, and placed Priochilus in Pompilinae .

Priochilus and Balboana are smaller genera, with only 21 and six described species, respectively (F. Fernandez, pers. comm.). However, this is probably an underestimate, based on our qualitative assessment of the diversity of unassigned specimens present in collections. Priochilini is distinguished by (1) lacking malar space; (2) having the propodeum with an angled de- clivity; and (3) having males with short pronotum, which slopes abruptly. The natural history of Balboana remains unknown, whereas Priochilus species use mud pellets to build aerial nests ( Evans & Shimizu, 1996; Auko, Silvestre & Pitts, 2013) similar to those of Ageniellini ( Pepsinae ).