Axinidris

Axinidris is an arboreal genus with an omnivorous diet and its members seem to prefer moist rainforest habitats where they nest in hollow, living or dead stems, or in rotten wood (Shattuck, 1991; Snelling, 2007). Revisions by Shattuck (1991) and Snelling (2007) allow for easy identification of species.

Identification
Shattuck (1992) - Worker: Anteromedial clypeal margin with a distinct notch separated from the general outline by distinct, angular corners; propodeum armed with short, rounded spines located near the dorsal margin of the declivitous face (occasionally spines elongate, reduced to angles, or absent); propodeal spiracle located dorsally and medially along the dorsal face of the propodeum and with at least the anterior margin raised on a slight projection (thus directing the spiracular opening posteriorly); medial region of propodeum (between the propodeal spines, when present) with a longitudinal carina (occasionally expanded into a dorsal flange, or absent; if absent, propodeum with lateral angles); petiolar node broadly rounded dorsally and strongly inclined anteriorly. Sub-Saharan Africa. Queen: Anteromedial clypeal margin with a distinct notch separated from the general outline by distinct, angular corners; propodeal spiracles located dorsally and medially along the dorsal face of the propodeum; declivitous face of propodeum concave; first gastral segment projecting anteriorly, but not concealing petiole in dorsal view; hind wing without closed cells; propodeum with or without spines or angles. Male: Anteromedial clypeal margin with a distinct notch separated from the general outline of the margin by distinct, angular corners; mandible with about 27 teeth and no denticles; first gastral segment strongly inclined anteriorly (but not concealing the petiole in dorsal view), and with a groove or indentation for the reception of the basal portion of the petiole; petiolar node strongly inclined anteriorly and with the anterior face much shorter than the posterior face; hind wing without closed cells.)

The worker caste of Axinidris can be distinguished from all other dolichoderines based on the dorsal propodeal spiracular placement, the angles or spines near the propodeal angle and the strongly anteriorly inclined and dorsally rounded petiolar node. Additionally, most species have a medial plate or carina on the propodeum. The propodeal spines and medial plate are extremely large in the type species (Axinidris acholli) however these characters are less dramatic in most Axinidris species

Distribution
Axinidris is endemic to the Afrotropical region, and seems to be mostly restricted to the Guineo-Congolian rainforest belt from West Africa to the Kakamega Forest in Western Kenya, with few species occurring also in Eastern or Southern Africa (Snelling, 2007).

Biology
The limited biological information available for Axinidris species suggests that they nest and forage arboreally. This likely accounts for the low number of collections of these widely distributed ants.

Worker Morphology
These characters are collated in the Worker Morphology table.

Nomenclature

 *  AXINIDRIS [Dolichoderinae: Tapinomini]
 * Axinidris Weber, 1941a: 192. Type-species: Axinidris acholli, by original designation.

Description
Shattuck (1992):

Worker
HEAD. Vertex flat to weakly concave. Compound eyes present, approximately round; relatively anterior on head. Ocelli absent. Antennae 12 segmented. Scape short, at most surpassing the vertex by less than one-third its length. Anterolateral clypeal margin even with the mediolateral region. Anteromedial clypeal margin with a distinct, central notch separated from the general outline of the margin by distinct, angular corners. Anterior clypeal setae 2-12; about the same length as the closed mandibles (sometimes with a few additional short hairs); moderately curved ventrally. Posterior clypeal margin between the anterior and posterior surfaces of the antennal socket cavities. Anterior tentorial pit nearer the antennal socket than the mandibular insertion. Frontal carina present. Anterolateral hypostoma reduced to a thin sclerite. Medial hypostoma entire. Psammophore absent. MOUTHPARTS. Palp formula 6:4. Third maxillary palp segment subequal in length to segment 4. Fifth maxillary palp segment at the apical extreme of segment 4. Mandible with about 6 teeth and about 3 denticles. Apical tooth subequal in length to the subapical tooth. Basal angle indistinct, with a relatively uninterrupted curve between the two margins. Basal margin denticulate along entire surface. MESOSOMA. Posteroventral pronotum lateral, rounded. Mesopleural process absent. Anteromedial mesosternum even with the lateral regions. Declivitous face of propodeum flat; dorsal face convex to flat, subequal in length to (rarely longer than) the declivitous face. Propodeal angle distinct. Pronotal spines absent (but ridged laterally in some species). Erect pronotal hairs 0-8; short, about as long as maximum scape width or elongate and much longer than the maximum scape width. Mesonotal spines absent. Propodeal spines present and distinct, or reduced to protuberances (and with a central, dorsal ridge or plate). Propodeal tooth absent. Dorsal pro-mesonotal junction with the pronotum and mesonotum even. Metanotal groove forming a distinct angle between the mesonotum and propodeum. Metanotal spiracle dorsal and lying on the dorsal surface when viewed in lateral profile. Propodeal spiracle dorsal and medially along the basal propodeal face. Hind tibial spur with well developed barbules along entire inner surface (except extreme base). PETIOLE. Scale present; rounded and forming an even arch dorsally; strongly inclined anteriorly and with the anterior face much shorter than the posterior face. Venter without a lobe. GASTER. First tergite projecting anteriorly, but not concealing the petiole in dorsal view and with a groove or indentation for the reception of the basal portion of the petiole. Anterior tergosternal suture of the first segment absent immediately lateral of the helcium and with the lateral section ofthe suture terminating immediately above the helcium. Fifth tergite vertical and with the distal terminus of the gaster not well defined. Gastral compression dorsoventral. Fourth sternite flat across entire posterior border. GENERAL CHARACTERS. Worker caste monomorphic. Chromosome number unknown. Integument thin and flexible, weakly sculptured. PROVENTRICULUS. Not examined.

Queen
HEAD. Vertex flat to weakly concave. Compound eyes relatively anterior on head. Antennae 12 segmented. Scape short, surpassing the vertex by less than one-half scape length. Anterolateral clypeal margin even with the mediolateral region. Anteromedial clypeal margin with a distinct, central notch separated from the general outline of the margin by distinct, angular corners. Anterior clypeal setae 6-16; short, less than twice the maximum scape diameter to about the same length as the closed mandibles; straight. Posterior clypeal margin posterior to the anterior surfaces of the antennal socket cavities. Anterior tentorial pit nearer the antennal socket than the mandibular insertion. Anterolateral hypostoma reduced to a thin sclerite. Medial hypostoma entire. Psammophore absent. MOUTHPARTS. Palp formula 6:4. Third maxillary palp segment subequal in length to segment 4. Fifth maxillary palp segment at the apical extreme of segment 4. Mandible with 8-9 teeth and no denticles. Apical tooth slightly longer than the subapical tooth. MESOSOMA. Posteroventral pronotum lateral, rounded or angled. Episternal suture complete. Mesopleural process absent. Axilla absent dorsally. Declivitous face of propodeum concave; dorsal face weakly convex (sometimes with a central carina or plate), longer than the declivitous face. Propodeal angle distinct. Propodeal suture absent. Pronotal spines absent. Erect mesoscutal hairs 0-4; when present short, less than twice the maximum scape diameter. Propodeal spines present as protuberances. Propodeal tooth absent. Propodeal spiracle dorsal and medial along the dorsal face. Hind tibial spur with well developed barbules along entire inner surface (except extreme base). WINGS. Radial cell closed. Fore wing with 1 cubital and 1 discoidal cell. Hind wing cells absent. PETIOLE. Scale present; rounded and forming an even arch dorsally, ridged and with a distinct angle dorsally, or spined and with a double tooth or projection dorsally; strongly inclined anteriorly and with the anterior face much shorter than the posteriorface. Venter without a lobe. GASTER. First segment projecting anteriorly, but not concealing the petiole in dorsal view and with a groove or indentation for the reception of the basal portion of the petiole. Fifth tergite vertical and with the distal terminus of the gaster not well defined (additionally, the sclerite is reduced longitudinally). Gastral compression absent (gaster circular in cross section). Fourth sternite flat across entire posterior border.

Male
HEAD. Inner margin of eye entire, flat. Scape length shorter than the length offunicular segments 2+3. First funicular segment cylindrical or cone- shaped. Second funicular segment cylindrical, straight. Funicular segments 2 and 3 at most twice as long as broad. Third and fourth funicular segments straight. Anteromedial c1ypeal margin with a distinct, central notch separated from the general outline of the margin by distinct, angular corners. Anterior clypeal setae about 10; short, about as long as the maximum diameter of the scape; straight. Posterior clypeal margin between the anterior and posterior surfaces of the antennal cavities. Anterior tentorial pit nearer the antennal socket than the mandibular insertion. Anterolateral hypostoma reduced to a thin sclerite. Medial hypostoma entire. MOUTHPARTS. Palp formula 6:4. Third maxillary palp segment subequal in length to segment 4. Fifth maxillary palp atthe apical extreme of segment 4. Mandible with about 27 teeth and no denticles. Apical tooth slightly longer than the subapical tooth. MESOSOMA. Posteroventral pronotum lateral, rounded or angled. Episternal suture present, complete. Axilla constricted medially, and entire. Anterior axillar suture straight. Declivitous and dorsal faces of propodeum convex. Propodeal angle indistinct. WINGS. Radial cell closed. Fore wing with 1 cubital and 1 discoidal cell. Pterostigmal appendage absent. Hind wing cells absent. PETIOLE. Scale present; rounded and forming an even arch dorsally; strongly inclined anteriorly and with the anterior face much shorter than the posterior face. Venter without a lobe. Attachment to gaster narrow. GASTER. First segment projecting anteriorly, but not concealing the petiole in dorsal view and with a groove or indentation for the reception of the basal portion of the petiole. GENITALIA. Pygostyles present. Posterior margin of subgenital plate with a 'V" -shaped notch. Paramere entire. Digitus with a down-turned tip. Cuspis ventral of digitus. Ventral lobe of volsella present as concave lobe. Aedeagus without ventral teeth.