Lioponera

This is the most species-rich genus that is revived from synonymy under Cerapachys. Lioponera occurs only in the Old World and all species observed thus far prey on other ants.



Identification
Borowiec (2016) - Worker The workers of Lioponera are distinguishable using the combination of a unique cuticular flange present on the posterior edge of the hind coxa, just posterior to the femur attachment, at least the anterior half of the petiole being dorsolaterally marginate, and a peculiar development of the metatibial gland that forms an open slit in the cuticle. The coxal flange should not to be confused with the elevated faces of coxa that can be conspicuous when there is a deep trench leading to the articulation with the femur, as can be sometimes seen in e.g. Simopone. The coxal flange and metatibial gland have been reduced in a handful of Australasian species, but in these the dorsolateral carinae of petiole and (usually) also postpetiole and mesosoma, are prominent. The dorsolateral margination of the body is characteristic and in most species very conspicuous on the abdominal segments II (petiole) and III. In a few species the margination extends from the head to the abdominal segment IV. The only other genera that can possess somewhat similar dorsolateral carinae on the petiole are Acanthostichus, Cerapachys, and Cylindromyrmex. The workers of those groups, however, do not possess a coxal flange.

Male The males of the many species of Lioponera are variable. Several characteristics can point to the affinity with this genus: antennae are 13-segmented, costal vein (C) is always absent from the fore wing, a ‘free stigmal vein’ (2r-rs&Rs·f4–5) is present and R·f3 and Rs·f2–3 are always absent. Cross-vein 2rs-m is usually absent but its traces can be rarely seen as a weak spectral vein arising close to 2r-rs. There is a constriction between abdominal segments III and IV but no succeeding segments and the middle tibiae are armed with a single spur. The notauli are present or absent, pretarsal claws are unarmed, and the palp formula is either 4,3 or 3,2. Compare diagnoses of the genera where a free stigmal vein is also found (Eburopone, Ooceraea, Syscia, Tanipone). Eburopone can be distinguished by costal (C) vein always present in the fore wing, Ooceraea and Syscia have 12- or 11-segmented antennae, and Tanipone has very long, 6-segmented maxillary palps that are extruded in mounted specimens and reach the occipital foramen.

Distribution
This is the most species-rich lineage outside the true army ants, distributed throughout the Old World, from Africa to Oceania, with a major radiation in Australia.

Species richness
Species richness by country based on regional taxon lists (countries with darker colours are more species-rich). View Data



Biology
The means of nest-founding of cerapachyines is unknown. In southwestern Australia, Clark (1923, 1924) found solitary individuals of Lioponera angustata and Lioponera constricta under a stone and a log respectively, and thought that the latter, at least, was founding a nest. However, it is not even certain that these specimens were reproductives, let alone founding queens, since no brood was found with either one, and both are “ergatoid” (i.e., possibly worker) in form.

Borowiec (2016) - Members of this lineage have been observed both in the field and in the laboratory (Brown 1975, Clark, 1924a and 1924b, Hölldobler 1982, Wilson 1958). As with most other dorylines, they are predators of other ants and a variety of prey species have been reported. Hölldobler (1982) studied an Australian Lioponera species near turneri under laboratory conditions. He showed that scouts recruit nestmates to raids via a pheromone trail, the species exhibited a preference for Pheidole when presented with a variety of other ants, and that the brood of the prey was paralyzed by stinging and stored alive for up to two months. Brood production is apparently not synchronized, at least in some species. Clark (1924a, 1924b) observed the Australian species Lioponera clarki and Lioponera punctatissima foraging singly around its nest but did not mention any prey; he reported that the workers were peculiar in holding their abdomens over the mesosoma when foraging in both species. Some Australian species are said to be crepuscular foragers, active in either morning or evening, while others are capable of raiding during the hottest parts of the day (Clark 1924b).

Lioponera nests are found in a variety of microhabitats, including soil, under stones, in rotting logs or arboreally in hollow twigs (Wilson 1958, Brown 1975).

Nomenclature

 *  LIOPONERA  [Dorylinae]
 * Lioponera Mayr, 1879: 666. Type-species: Lioponera longitarsus, by monotypy.
 * Lioponera subgenus of Cerapachys: Forel, 1892l: 244.
 * Lioponera revived status as genus: Dalla Torre, 1893: 17.
 * Lioponera junior synonym of Cerapachys: Brown, 1975: 19.
 * Lioponera as genus: Borowiec, 2016: 156.
 * NEOPHYRACACES [junior synonym of Cerapachys]
 * Neophyracaces Clark, 1941: 76. Type-species: Phyracaces clarus, by original designation.
 * Neophyracaces junior synonym of Cerapachys: Brown, 1975: 19.
 * Neophyracaces junior synonym of ''Lioponera": Borowiec, 2016: 156.
 * PHYRACACES [junior synonym of Cerapachys]
 * Phyracaces Emery, 1902c: 23. Type-species: Cerapachys mayri, by original designation.
 * Phyracaces junior synonym of Cerapachys: Brown, 1975: 19.
 * Phyracaces junior synonym of ''Lioponera": Borowiec, 2016: 156.

Borowiec (2016) - Borowiec (2016) - Originally Lioponera was described for Lioponera longitarsus, a species from India (Mayr 1879). In Genera Insectorum, Emery (1911) recognized Lioponera, Phyracaces and Cerapachys in his tribe Cerapachyini. Since then, several species were described in Lioponera, but many more taxa placed here under that name were originally described in Phyracaces. Brown (1975) synonymized both taxa under Cerapachys.

Lioponera is part of a well-supported Old World clade where the intergeneric relationships are known (Brady et al. 2014, Borowiec, in prep.). Within this clade, Lioponera branches off first and is sister to the (Lividopone (Parasyscia plus Zasphinctus) clade. A phylogeny of the relatively few species that have been sequenced suggests that the genus may have originated in Africa and later spread to the Indomalayan and Australasian regions.

Worker
Borowiec (2016) - Head: Antennae with 12 segments. Apical antennal segment not enlarged, not broader and longer than two preceding segments combined to moderately enlarged, broader than and about equal in length to two preceding segments combined. Clypeus with cuticular apron. Lateroclypeal teeth absent. Parafrontal ridges reduced. Torulo-posttorular complex vertical. Antennal scrobes absent. Labrum with median notch or concavity. Proximal face of stipes projecting beyond inner margin of sclerite, concealing prementum when mouthparts fully closed. Maxillary palps 4- or 3-segmented. Labial palps 3- or 2-segmented. Mandibles triangular, with teeth. Eyes present, composed of more than 20 ommatidia. Ocelli absent or more rarely present. Head capsule with differentiated vertical posterior surface above occipital foramen. Ventrolateral margins of head with or without lamella or ridge extending towards mandibles and beyond carina surrounding occipital foramen. Posterior head corners dorsolaterally immarginate or marginate. Carina surrounding occipital foramen ventrally absent. Mesosoma: Pronotal flange separated from collar by distinct ridge. Promesonotal connection with suture completely fused. Pronotomesopleural suture visible, unfused partway to notal surface. Mesometapleural groove deeply impressed, conspicuous. Transverse groove dividing mesopleuron present. Pleural endophragmal pit concavity present. Mesosoma dorsolaterally immarginate, weakly marginate, or conspicuously marginate. Metanotal depression or groove on mesosoma absent. Propodeal spiracle situated low on sclerite. Propodeal declivity with or without distinct dorsal edge or margin and rectangular in posterior view. Metapleural gland with bulla visible through cuticle. Propodeal lobes present, well developed. Metasoma: Petiole anterodorsally immarginate, dorsolaterally marginate, and laterally above spiracle immarginate or marginate. Helcium in relation to tergosternal suture placed at suture and axial. Prora simple, not delimited by carina or a V-shaped protrusion. Spiracle openings of abdominal segments IV–VI circular. Abdominal segment III anterodorsally immarginate or marginate and dorsolaterally immarginate or marginate. Abdominal segment III more than half size of succeeding segment IV, which is weakly constricted at presegmental portion (uninodal waist). Girdling constriction of segment IV present, i.e. pre- and postsclerites distinct. Cinctus of abdominal segment IV gutter-like, not sculptured or cross-ribbed. Abdominal segment IV not conspicuously largest segment. Abdominal tergite IV not folding over sternite, and anterior portions of sternite and tergite equally well visible in lateral view. Girdling constriction between pre- and posttergites of abdominal segments V and VI absent. Girdling constriction between pre- and poststernites of abdominal segments V and VI absent. Pygidium large, with impressed medial field and armed with modified setae. Hypopygium unarmed. Legs: Mid tibia with pectinate spur or, more rarely, with barbulate spur and simple spur. Hind tibia with single pectinate spur. Hind basitarsus not widening distally, circular in cross-section. Posterior flange of hind coxa produced as raised lamella or rarely without lamella. Metatibial gland present in form of slit or orifice in cuticle or rarely absent. Metabasitarsal gland absent. Hind pretarsal claws simple. Polymorphism: Monomorphic.

Queen
Borowiec (2016) - Alate or ergatoid; apparent intercastes have also been reported. Alate or apparently alate (known from dealated specimens) gynes are known in a number of species, for example in Lioponera clarki, Lioponera daikoku, Lioponera fervida, Lioponera huode, Lioponera pubescens, Lioponera turneri. Ergatoid gynes are known to vary in morphology, from scarcely different from the worker, through possessing relatively larger eyes and ocelli, to having the mesosomal morphology identical to that of winged queens but possessing no wings. Ergatoids have been reported in, for example, Lioponera angustata, Lioponera bicolor, Lioponera constricta, Lioponera elegans, Lioponera gilesi, Lioponera nigriventris, Lioponera punctatissima, Lioponera simmonsae. Malagasy species related to Lioponera kraepelinii and Lioponera mayri also possess ergatoid gynes (author’s observations). Intercastes with morphologies intermediate between workers and alate gynes have been reported to occur along with fully developed gynes in L. clarki (Clark 1924a, 1924b). See Clark (1924a, 1924b) for example descriptions and illustrations of Lioponera gynes.

Male
Borowiec (2016) - Head: Antennae with 13 segments. Clypeus with cuticular apron. Parafrontal ridges absent. Torulo-posttorular complex vertical. Maxillary palps 3-segmented. Labial palps 2-segmented. Mandibles triangular, edentate. Ventrolateral margins of head with or without cuticular ridge extending towards mandibles and beyond carina surrounding occipital foramen. Carina surrounding occipital foramen ventrally absent. Mesosoma: Pronotal flange not separated from collar by distinct ridge. Notauli absent or present. Transverse groove dividing mesopleuron present. Propodeal declivity with distinct dorsal edge or margin. Metapleural gland opening present. Propodeal lobes present. Metasoma: Petiole anterodorsally immarginate or marginate, dorsolaterally marginate, and laterally above spiracle marginate. Helcium in relation to tergosternal suture placed at suture and axial. Prora forming a simple U-shaped margin or U-shaped protrusion. Spiracle openings of abdominal segments IV–VI circular. Abdominal segment III more than half size of succeeding segment IV; latter weakly constricted at presegmental portion (uninodal waist). Girdling constriction of segment IV present, i.e. pre- and postsclerites distinct. Cinctus of abdominal segment IV gutter-like and cross-ribbed. Girdling constriction between pre- and postsclerites of abdominal segments V and VI absent. Abdominal segment IV not conspicuously largest segment. Abdominal sternite VII simple. Abdominal sternite IX cleft or modified into two spines, with lateral apodemes about as long as medial apodeme, directed anteriorly (towards head). Genitalia: Cupula long relative to rest of genital capsule and of approximately equal length on both dorsal and ventral surfaces. Basimere broadly fused to telomere, with no sulcus trace at junction, and ventrally with left and right arms abutting. Telomere gradually tapering toward apex. Volsella gradually tapering toward apex. Penisvalva constricted basally, distally a widening triangle, serrated ventrally. Legs: Mid tibia with single pectinate spur. Hind tibia with single pectinate spur. Posterior flange of hind coxa produced as raised lamella or not. Metatibial gland absent. Metabasitarsal glands absent. Hind pretarsal claws simple. Wings: Tegula present, broad, demiovate in shape. Vein C in fore wing absent. Pterostigma broad. Abscissa R·f3 absent. Abscissae Rs·f2–3 absent. Cross-vein 2r-rs most often present and forming base of ‘free stigmal vein’ (2r-rs&Rs·f4–5) in absence of Rs·f3 and 2rs-m or present and connected to Rs·f2–3&Rs·f4 or, rarely, absent. Abscissae Rs·f4–5 absent or present, fused in absence of 2rs-m or, more rarely, differentiated into Rs·f4 and Rs·f5 by 2rs-m. Abscissa M·f2 in fore wing absent or contiguous with Rs+M. Abscissa M·f4 in fore wing present, not reaching wing margin. Cross-vein 1m-cu in fore wing present or more rarely absent. Cross-vein cu-a in fore wing present, arising from M+Cu and proximal to M·f1 or more rarely absent. Vein Cu in fore wing present, with only Cu1 branch prominent or absent past M+Cu. Vein A in fore wing with abscissa A·f1 present with abscissae A·f1 and A·f2 present. Vein C in hind wing absent. Vein R in hind wing absent. Vein Sc+R in hind wing present. Abscissa Rs·f1 in hind wing absent or present, shorter than 1rs-m. Abscissa Rs·f2 in hind wing absent or present, not reaching wing margin. Cross-vein 1rs-m in hind wing absent or present, about as long as M·f1. Vein M+Cu in hind wing absent or present. Abscissa M·f1 in hind wing absent or present. Abscissa M·f2 in hind wing absent. Cross-vein cu-a in hind wing absent or present. Vein Cu in hind wing absent or present. Vein A in hind wing absent or with abscissa A·f1 present.

Larvae
Borowiec (2016) - Larvae of Lioponera have been described by Wheeler and Wheeler (1964a). Cocoons are present.