Buniapone, Schmidt & Shattuck, 2014

Schmidt, C. A. & Shattuck, S. O., 2014, The Higher Classification of the Ant Subfamily Ponerinae (Hymenoptera: Formicidae), with a Review of Ponerine Ecology and Behavior, Zootaxa 3817 (1), pp. 1-242 : 81-83

Buniapone gen. nov.

Fig. 10

Type-species: Ponera amblyops Emery, 1887: 434 ; by present designation.

Buniapone is a monotypic genus restricted to Southern and Southeast Asia. Very little is known about its habits.

Etymology. Buniapone is named after the Orang Bunian, a race of invisible forest beings in the traditional folklore of Malaysia (where the genus is common), reflecting the hypogeic sylvan habits of these ants. The suffix - pone is derived from the subfamily name Ponerinae .

Diagnosis. Buniapone is a morphologically distinctive genus and its workers are readily identified by the following combination of characters: long and narrow toothed mandibles, blunt medial clypeal projection, greatly reduced eyes, obsolete metanotal groove, ovoid propodeal spiracles, complex metapleural gland orifice, and squamiform petiole. Superficially, Buniapone most closely resembles Centromyrmex , Promyopias , and certain Neotropical Cryptopone species , but Buniapone has eyes, lacks the anterolateral position of the metapleural gland orifice of Centromyrmex , lacks the linear mandibles of Promyopias , and lacks the small closely approximated frontal lobes and circular propodeal spiracles of Cryptopone . Though Buniapone shares several apomorphies with its sister genus Paltothyreus , they are superficially very different and unlikely to be confused. Myopias also has a blunt medial clypeal projection, but it is much more pronounced than in Buniapone , and Myopias lacks the other characters diagnostic of Buniapone .

Synoptic description. Worker. Medium-sized (TL 5.5–6.5 mm; Emery, 1887) ants with the standard characters of Ponerini . Mandibles long and narrow, with seven prominent teeth on the masticatory margin, a short basal margin, and a basal groove. Anterior clypeal margin forming a narrow blunt medial projection. Frontal lobes moderately large. Eyes very small (with about four ommatidia), located anterior of head midline. Metanotal groove obsolete. Propodeum narrowed dorsally. Propodeal spiracles ovoid. Metapleural gland orifice opening posterolaterally, with anterior and posterior cuticular flanges. Mesotibae and meso-/metabasitarsi with stout traction setae. Metatibial spur formula (1s, 1p). Petiole squamiform. Helcium projecting from near midheight of anterior face of A3. Girdling constriction between pre- and postsclerites of A4 apparent. Head, gaster and mesosomal dorsum punctate, the sides of the mesosoma longitudinally striate. Head and body with scattered pilosity and a dense pubescence. Color orange.

Queen. Similar to worker, but larger (TL 9.25 mm; Emery, 1889) and winged.

Male. See description in Santschi (1928).

Larva. Not described.

Geographic distribution. Buniapone is restricted to Southern and Southeast Asia, ranging from southern China to the islands of southern Indonesia and as far west as India.

Ecology and behavior. Virtually nothing is known about the habits of Buniapone , other than that they are hypogeic. They are presumably predatory, though their prey preferences are unknown. One of us (CS) observed large numbers of B. amblyops workers congregated at a palm oil bait sunk into the ground, suggesting that they are not strictly carnivorous and that they may employ some kind of nestmate recruitment to food sources, like their sister genus Paltothyreus .

Phylogenetic and taxonomic considerations. We are erecting Buniapone as a new genus to house the single species Ponera amblyops Emery (1887) (currently Pachycondyla amblyops ). This species has had probably the most convoluted taxonomic history of any ponerine. It was originally placed in Ponera ( Emery, 1887) , then moved to Trapeziopelta (= Myopias ; Emery, 1889), Belonopelta ( Emery, 1897a) , Pachycondyla ( Emery, 1900b) , Pseudoponera ( Emery, 1901; Bingham, 1903), Euponera ( Forel, 1905) , and most recently Pachycondyla again (W. L. Brown, in Bolton, 1995). Emery (1901) designated it the type species of Pseudoponera , despite having implicitly erected Pseudoponera the previous year with a different type species (what is now Ps. stigma ; Emery, 1900a). This mistake was repeated throughout much of the subsequent taxonomic literature, but was finally noted by Bolton (2003).

The confusion over the taxonomic placement of B. amblyops is understandable given its unique structure. Schmidt's (2013) molecular phylogeny of the Ponerinae resolves this uncertainty, as Buniapone is very strongly resolved as sister to Paltothyreus , though sister relationships to either Euponera or Myopias were not statistically rejected. The apparent sister relationship between Buniapone and Paltothyreus is a novel and surprising result which is nevertheless also strongly supported by morphology (see discussion under Paltothyreus ). Given that these two genera share several apomorphies and that their divergence is relatively recent, they could arguably be synonymized. We feel that their morphological and ecological differences are stark enough, however, to warrant distinct generic status, similar to the situation with Dinoponera and Pachycondyla .

Buniapone’s close relationship to Paltothyreus is perhaps the most surprising result in Schmidt’s (2013) molecular phylogeny. Buniapone is a medium-sized hypogeic ant restricted to Asia, while Paltothyreus is a very large epigeic ant restricted to Sub-Saharan Africa. Given their phylogenetic position within the Odontomachus group, it is clear that Buniapone is morphologically the more derived of the two genera. The most recent common ancestor of Buniapone and Paltothyreus was most likely a large epigeic ant like most members of the Odontomachus group. Further information about the behavior of Buniapone would be invaluable in understanding the remarkable divergence between these two genera.

Buniapone bears superficial morphological similarity to some Neotropical Cryptopone species (those formerly placed in Wadeura ) and to Promyopias . These similarities are presumably the result of convergence due to their shared hypogeic habits as Cryptopone belongs to the Ponera group and preliminary results suggest that Promyopias , while also belonging to the Odontomachus group, is not particularly closely related to Buniapone (P.S. Ward, pers. comm.).

Figures

FIGURE 10. Worker caste of Buniapone amblyops: lateral and dorsal view of body and full-face view of head (CASENT0172431, April Nobile and www.antweb.org); world distribution of Buniapone.