Asphinctopone Santschi, 1914: 318
Asphinctopone silvestrii Santschi, 1914: 318
Lepidopone Bernard, 1953: 207
Ponerinae
Ponerini
Lepidopone lamottei Bernard, 1953: 208
Asphinctopone silvestrii Santschi, 1914
Brown, 1953b: 2
Lepidopone
Asphinctopone
Asphinctopone
The Higher Classification of the Ant Subfamily Ponerinae (Hymenoptera: Formicidae), with a Review of Ponerine Ecology and Behavior
Schmidt, C. A.
Shattuck, S. O.
Zootaxa
2014
2014-06-18
3817
1
1
242
Lepidopone Bernard, 1953: 207
Lepidopone lamottei Bernard, 1953: 208
342C
373782
Santschi
Santschi
[151,445,692,718]
Insecta
Formicidae
Asphinctopone
Animalia
Hymenoptera
69
70
Arthropoda
genus
Fig. 7
Asphinctopone Santschi, 1914: 318(as genus). Type-species: Asphinctopone silvestrii Santschi, 1914: 318; by monotypy. Lepidopone Bernard, 1953: 207(in Ponerinae, Ponerini). Type-species: Lepidopone lamottei Bernard, 1953: 208(junior synonym of Asphinctopone silvestrii Santschi, 1914); by monotypy. Brown, 1953b: 2( Lepidoponeas junior synonym of Asphinctopone). Asphinctoponeis a small genus (three described species) restricted to tropical Africa. Nothing is known about its habits.
Diagnosis. Asphinctoponeis morphologically distinctive and unlikely to be confused with any other genus. Important diagnostic apomorphies of the genus include the complex clypeus (see description below), the long apical antennomere, the strongly impressed metanotal groove, the divided mesopleuron, and the lack of differentiated presclerites in A4. Additional apomorphies of Asphinctoponeinclude characters of the subpetiolar process and the helcium (described in detail by Bolton& Fisher, 2008a). The presence of a small process on the basal mandibular margin and strongly impressed promesonotal suture, previously thought to be apomorphies, do not occur in all known species and are therefore not of use in diagnosing this genus ( Hawkes, 2010). Superficially, workers of Asphinctoponeperhaps most resemble small Brachyponera, due to their similarly impressed metanotal grooves, strongly narrowed propodeal dorsa, round or ovoid propodeal spiracles, squamiform petioles, and absent or weak gastral constriction. These genera strongly differ in many characters, however, including those of the mandibles (triangular and with a basal pit in Brachyponera, subtriangular and with a unique process on the basal margin in Asphinctopone) and clypeus (broadly convex in Brachyponera, complex in Asphinctopone), their metatibial spur count (two in Brachyponera, one in Asphinctopone), and many other characters. Synoptic description. Worker.Small (TL 3.3–3.7 mm) ants with the standard characters of Ponerini. Mandibles subtriangular, with five teeth, a small process on the basal margin near the mandibular articulation present in some species, and a faint basal groove. Clypeus projecting anteriorly, with a small rounded lobe medially, on either side of which is a shallow concavity and then an angular projection. Frontal lobes closely approximated and of moderate size. Antennae with the three or four apical antennomeres forming a weak club, the apical antennomere longer than the preceding five (or four) segments combined. Eyes small, located anterior of head midline. Promesonotal suture sometimes relatively deeply impressed, the metanotal groove always deeply impressed. Mesopleuron divided by a transverse groove. Propodeal dorsum strongly narrowed and relatively short, the posterior face relatively long. Propodeal spiracles ovoid. Metatibial spur formula (1p). Petiole squamiform, the scale thin in side view but broad in dorsal view. A4 without differentiated presclerites, and hence the gaster without a girdling constriction. Head and body shiny to very sparsely punctate, with sparse pilosity and pubescence. Color orange to reddish brown. Seedescription by Bolton& Fisher (2008a)and Hawkes (2010)for further details and for discussion of additional important characters, such as those of the helcium and subpetiolar process. Queen.Similar to worker but slightly larger, winged, with ocelli and larger eyes, and with the other characters typical of winged ponerine queens ( Bolton& Fisher, 2008a). Male.Unknown. Larva. Notdescribed. Geographic distribution. Asphinctoponeis rarely collected and seems to be at low density where it occurs, but is widespread in central and western Africa with a single species known from eastern Africa, having been collected in the Ivory Coast, Nigeria, Cameroon, the Central African Republic, Ghana, Guinea, Gabonand Tanzania( Bolton & Fisher, 2008a; Hawkes, 2010).
Ecology and behavior.Nothing definite is known about the habits of Asphinctopone. Specimens have been collected in leaf litter, soil, rotting wood, and an abandoned termitary (Déjean et al., 2006; Bolton& Fisher, 2008a) while one workerwas collected during the evening ( Hawkes, 2010). The presence of Asphinctoponeworkers in these microhabitats, along with their reduced eyes, implies a cryptobiotic existence. Bolton& Fisher(2008a)suggest that the derived mandibular structure of the genus is indicative of prey specialization, though its feeding habits remain unknown. Phylogenetic and taxonomic considerations. Santschi (1914)described Asphinctoponeas a monotypic genus to hold his new species A. silvestrii. Bernard (1953)later erected the genus Lepidoponefor his new species L. lamottei. Bernard differentiated his new genus from the obviously closely related Asphinctoponeby supposed differences of the coxae, petiole and gaster. Brown (1953c) concluded that the justification for separating Lepidoponefrom Asphinctoponewas weak, and synonymized them. Bolton& Fisher(2008a)revised the specieslevel taxonomy of Asphinctopone. Schmidt (2013)was unable to include Asphinctoponein his phylogeny of Ponerinae, and the morphological traits of the genus give only a few clues to its phylogenetic position. Ouellette et al.(2006)included an unidentified Asphinctoponespeciesin their 28S phylogeny of the poneroid subfamilies, and found weak support for a close relationship between Asphinctoponeand Odontomachusor Anochetus, suggesting membership of Asphinctoponein the OdontomachusGenus Group. Morphological evidence does not give a strong indication of the phylogenetic relationships of Asphinctopone, though after considering the various possibilities we conclude that Asphinctoponemost likely is a member of the OdontomachusGroup, as suggested by Ouellette et al.’s (2006) molecular results. Bolton& Fisher(2008a)found similarities in the structure of the petiolar sternite and helcium in Asphinctopone, Phrynoponera,and Brachyponera, though they argued against these similarities representing synapomorphies of all three genera or any given pair of them. Still, the possibility cannot be rejected, especially given other superficial similarities between Asphinctoponeand both Phrynoponeraand Brachyponera. The presence of only a single metatibial spur in Asphinctoponewould be unusual among Odontomachusgroup genera, but some species of Anochetushave a similar reduction in spur count. Spur count is roughly correlated with body size, so the loss of the second spur in Asphinctoponecould be the result of a reduction in body size, and would not exclude its placement in the Odontomachusgroup. Other morphological arguments for a placement in the Odontomachusgroup include the unconstricted gaster (present to a less extreme degree in most members of the group), the impressed metanotal groove (more commonly impressed in the Odontomachusgroup than in other genus groups), and the relatively large frontal lobes, which would argue against a placement in the Poneragroup, nearly all of which have very small frontal lobes. A placement of Asphinctoponewithin the Plectroctenagroup is unlikely, given its posteriorly-opening metapleural gland orifice, impressed metanotal groove, and narrowed propodeal dorsum. The possibility of a close relationship between Asphinctoponeand Hypoponeracannot be rejected, but is not supported by any particular putative synapomorphy. Finally, the biogeography of Asphinctopone(restricted to central and western Africa) lends credibility to a placement in either the Plectroctenaor Odontomachusgroups, which are apparently Afrotropical in origin. Weighing all the evidence, we find it most likely that Asphinctoponeis simply an unusually small member of the Odontomachusgroup, and we therefore tentatively include it there.