Vicinopone Bolton & Fisher, 2012

Borowiec, Marek L., 2016, Generic revision of the ant subfamily Dorylinae (Hymenoptera, Formicidae), ZooKeys 608, pp. 1-280 : 181-182

Taxon classification Animalia Hymenoptera Formicidae

Vicinopone Bolton & Fisher, 2012

Type-species.

Simopone conciliatrix , by original designation.

Vicinopone is a monotypic lineage of arboreal ants.

Diagnosis.

Worker. The workers of the sole species of Vicinopone are slender and small yellowish ants with large eyes and no ocelli. The cuticle is sculptured with weak punctation. Vicinopone is recognized by a combination of propodeal spiracle high on the sclerite and propodeal lobes present, no constrictions between abdominal segments IV, V, and VI, large pygidium armed with modified setae, no ocelli in the worker, 12-segmented antennae and no spur on the middle tibiae. This genus is most similar to Simopone with which it shares the lack of a mid tibial spur, but in Simopone the antennae are 11-segmented and workers have ocelli.

Male. The male of Vicinopone is unknown.

Description.

Worker.Head: Antennae with 12 segments. Apical antennal segment moderately enlarged, broader than and about equal in length to two preceding segments combined. Clypeus without 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 not projecting beyond inner margin of sclerite, prementum exposed when mouthparts fully closed. Maxillary palps 3-segmented. Labial palps 2-segmented. Mandibles triangular, edentate. Eyes present, composed of more than 20 ommatidia. Ocelli absent. Head capsule without differentiated vertical posterior surface above occipital foramen. Ventrolateral margins of head without lamella or ridge extending towards mandibles and beyond carina surrounding occipital foramen. Posterior head corners dorsolaterally immarginate. Carina surrounding occipital foramen ventrally present. Mesosoma: Pronotal flange separated from collar by distinct ridge. Promesonotal connection with Pronotomesopleural suture completely fused. Pronotomesopleural suture visible, unfused partway to notal surface. Mesometapleural groove weakly impressed. Transverse groove dividing mesopleuron absent. Pleural endophragmal pit concavity present. Mesosoma dorsolaterally immarginate. Metanotal depression or groove on mesosoma absent. Propodeal spiracle situated low on sclerite. Propodeal declivity with 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 marginate, dorsolaterally immarginate, and laterally above spiracle marginate. Helcium in relation to tergosternal Pronotomesopleural suture placed at posttergite and axial. Prora forming a U-shaped margin with median ridge. Spiracle openings of abdominal segments IV–VI circular. Abdominal segment III anterodorsally immarginate and dorsolaterally immarginate. 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 and 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, armed with modified setae. Hypopygium unarmed. Legs: Mid tibia without spurs. Hind tibia with single pectinate spur. Hind basitarsus not widening distally, circular in cross-section. Posterior flange of hind coxa not produced as raised lamella. Metatibial gland absent. Metabasitarsal gland absent. Hind pretarsal claws each armed with a tooth. Polymorphism: Monomorphic.

Male. Not described.

Gyne. Apparently alate, with ocelli and flight sclerites but only dealated specimens known ( Bolton and Fisher 2012).

Larva. Not described. Cocoons absent.

Distribution.

So far Vicinopone has been collected in Ghana, Gabon, Democratic Republic of the Congo, Uganda, and Tanzania but it is likely that it is more widely distributed in sub-Saharan Africa.

Taxonomy and phylogeny.

Vicinopone is a genus recently established by Bolton and Fisher (2012) to accommodate the only currently known species, Vicinopone conciliatrix .

The phylogenetic position of Vicinopone is uncertain ( Brady et al. 2014, Borowiec, in prep.).

Biology.

Little is known of the species’ habits, but the two known nest samples have been taken from dead twigs on trees, suggesting that this is an obligatory arboreal nester. Two dealate gynes were collected with the type nest series ( Brown 1975), suggesting that the ant may be polygynous. Brood production is not synchronized, as larvae and pupae of various stages were present in the nests at times of collection.

Species of Vicinopone

Vicinopone conciliatrix (Brown, 1975): Ghana