Tapinoma

Most Tapinoma species are arboreal and some live in close associations with myrmecophyte plants (Wheeler, 1922; Bolton, 1973a). In addition, they seem to be generalised foragers (Brown, 2000). Species of Tapinoma utilize a wide variety of nest sites, including open soil, soil covered with rocks, wood or other plant material, rotten or dead wood, plant stems, or almost any appropriately-sized preformed cavity. Nests are of moderate to large size, and may contain up to several hundred dealate queens. Tapinoma are general scavengers, but have a preference for honeydew and often tend aphids or coccids. (Shattuck 1992)

Identification
Shattuck (1992) - Worker: Mandibles with 3 to 7 teeth, about 7 denticles, and the basal angle indistinct and with a relatively uninterrupted curve between the masticatory and basal margins; petiolar scale reduced or absent; first gastral segment projecting anteriorly and concealing petiole in dorsal view; dorsal face of propodeum shorter than declivitous face; erect hairs generally lacking on pronotum. World wide Queen: Gastral compression dorsoventral; petiolar scale reduced or absent; dorsal face of propodeum shorter than declivitous face; first gastral segment projecting anteriorly and concealing petiole in dorsal view; basal angle of mandible indistinct, with a relatively uninterrupted curve between the masticatory and basal margins. Male: Scape length much longer than the length of funicular segments 1 +2+3; petiolar scale reduced, strongly inclined anteriorly; first gastral segment projecting anteriorly, sometimes concealing the petiole in dorsal view; mandible with 8 to 15 teeth and 0 to 3 denticles.

Workers can be separated from those of all other dolichoderine genera based on the lack of a petiolar node (occasionally greatly reduced), the lack of a basal mandibular angle, and the four apparent gastral tergites.

Fisher and Bolton (2007) - Within the Dolichoderinae two genera, Tapinoma and Technomyrmex, are isolated in their female castes by the synapomorphic extreme reduction of the petiole and its accommodation in a longitudinal groove or impression in the ventral surface of the first gastral tergite, which overhangs and conceals the petiole in dorsal view when the mesosoma and gaster are aligned. The petiole is so reduced in these two genera that in profile there is no trace of a node or scale; at most there is a very short raised surface immediately behind the peduncle. The function of this raised surface is to provide an insertion-site for the exterior levator muscle of the petiole.

Technomyrmex and Tapinoma are separated in the female castes by the contrasting morphologies of their gastral apices. In Technomyrmex the sclerites of the gastral apex are unspecialised, except that the pygidium is small. Gastral tergite 5 is therefore in line with tergites 1 – 4 and as a result all five tergites are visible in dorsal view. In contrast the pygidium in Tapinoma is reflexed, the fifth tergite being folded back and down, below the fourth tergite, and is clearly visible in ventral view. Also in that view the fourth tergite frequently forms a distinct projecting rim above the reflexed fifth. In consequence only gastral tergites 1 – 4 are visible in dorsal view.

Nomenclature

 *  TAPINOMA [Dolichoderinae: Tapinomini]
 * Tapinoma Foerster, 1850a: 43. Type-species: Tapinoma collina (junior synonym of Formica erratica), by monotypy.
 * Tapinoma senior synonym of Micromyrma: Mayr, 1863: 455; Emery, 1913a: 38; Smith, M.R. 1951a: 837; Shattuck, 1992c: 146.
 * Tapinoma senior synonym of Neoclystopsenella: Brown, 1988a: 337.
 * Tapinoma senior synonym of Semonius, Zatapinoma: Shattuck, 1992c: 146.
 * Tapinoma senior synonym of Pseudaphomomyrmex: Fisher & Bolton, 2007: 66.
 * MICROMYRMA [junior synonym of Tapinoma]
 * Micromyrma Dufour, 1857: 60. Type-species: Micromyrma pygmaea, by monotypy.
 * [Type-species not Formica erratica, unjustified subsequent designation by Wheeler, W.M. 1911f: 167.]
 * Micromyrma subgenus of Tapinoma: Santschi, 1928e: 475; Chapman & Capco, 1951: 192.
 * Micromyrma junior synonym of Tapinoma: Mayr, 1863: 455; Forel, 1878: 385; Dalla Torre, 1893: 164; Emery, 1913a: 38; Smith, M.R. 1951a: 837; Shattuck, 1992c: 146.
 * NEOCLYSTOPSENELLA [junior synonym of Tapinoma]
 * Neoclystopsenella Kurian, 1955: 133. Type-species: Neoclystopsenella luffae, by monotypy.
 * Neoclystopsenella junior synonym of Tapinoma: Brown, 1988a: 337.
 * PSEUDAPHOMOMYRMEX [junior synonym of Tapinoma]
 * Pseudaphomomyrmex Wheeler, W.M. 1920: 53. Type-species: Aphomomyrmex emeryi, by original designation.
 * Pseudaphomomyrmex junior synonym of Aphomomyrmex: Emery, 1925b: 44.
 * Pseudaphomomyrmex revived from synonymy: Chapman & Capco, 1951: 214.
 * Pseudaphomomyrmex in Dolichoderinae: LaPolla & Longino, 2006: 305.
 * Pseudaphomomyrmex junior synonym of Tapinoma: Fisher & Bolton, 2007: 66.
 * SEMONIUS [junior synonym of Tapinoma]
 * Semonius Forel, 1910f: 21. Type-species: Semonius schultzei, by monotypy.
 * Semonius junior synonym of Tapinoma: Shattuck, 1992c: 146.
 * ZATAPINOMA [junior synonym of Tapinoma]
 * Zatapinoma Wheeler, W.M. 1928a: 20. Type-species: Zatapinoma annandalei, by original designation.
 * Zatapinoma junior synonym of Tapinoma: Shattuck, 1992c: 146.

Description
Shattuck (1992):

Worker
HEAD. Vertex slightly convex to concave. Compound eyes present, approximately round; relatively anterior on head. Ocelli absent. Antennae 12 segmented (occasionally 11, rarely 8 segmented). Scape relatively short, at most surpassing the vertex by less than one-half (often less than one-third) its length. Anterolateral clypeal margin even with the mediolateral region. Anteromedial clypeal margin variable, either entire, without a central notch or concavity of any type; with a broad, shallow concavity; orwith a distinct, central notch separated from the general outline of the margin by distinct, angular corners. Anterior clypeal setae 2-6 (or absent); short, less than twice the maximum scape diameter or about the same length as the closed mandibles; straight or 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 3-6 (rarely 7) teeth and about 7 denticles. Apical tooth varying from subequal in length to, to slightly longer than, the subapical tooth. Basal angle indistinct, with a relatively uninterrupted curve between the two margins. Basal margin varying from denticulate distally, smooth proximally to denticulate along entire surface. MESOSOMA. Posteroventral pronotum lateral, rounded or angled. Mesopleural process absent. Anteromedial mesosternum even with the lateral regions. Declivitous and dorsal faces of propodeum convex to flat; dorsal face shorter than the declivitous face. Propodeal angle distinct (rarely with a dorsal lip or tooth). Mesosomal spines absent (propodeum rarely with a dorsal tooth). Erect pronotal hairs absent (rarely 2 to 12); when present elongate, much longer than the maximum scape width. Dorsal pro- meso notal junction with the pronotum and mesonotum even, or with the mesonotum slightly above the pronotum. Metanotal groove either reduced to a suture (and with the mesonotum and propodeum forming a continuous, uninterrupted surface) or forming a distinct angle between the mesonotum and propodeum. Metanotal spiracle lateral and ventral of the dorsal surface when viewed in lateral profile. Propodeal spiracle lateral and ventral of the propodeal dorsum. Hind tibial spur with well developed barbules along entire inner surface (except extreme base). PETIOLE. Scale absent to reduced; when present, ridged and with a distinct angle dorsally, and strongly inclined anteriorly and with the anterior face much shorter than the posterior face. Venter with a slight to well developed lobe. GASTER. First tergite projecting anteriorly and concealing the petiole in dorsal view and with a groove or indentation for the reception of the entire height of the petiole. Anterior tergosternal suture of the first segment absent immediately lateral of the helcium and with the lateral section of the suture extending anterodorsally and terminating near the dorsal surface of the gaster. Fifth tergite ventral, gaster with 4 apparent tergites. Gastral compression dorsoventral. Fourth sternite flat across entire posterior border. GENERAL CHARACTERS. Worker caste monomorphic or rarely dimorphic. Chromosome number 5, 7, 8 or 9 (2n=1 0, Tapinoma melanocephalum, Imai et al. 1984, Imai et al. 1985b; n=5, T. melanocephalum, Crozier 1970b; n=8, Tapinoma sessile, Crozier 1970b; 2n=16, T. sessile, Taber and Cokendolpher 1988; 2n=1 0, T. indicum, Imai et a/. 1984; n=7, Tapinoma indicum, Crozier 1975; n=8, Tapinoma erraticum, Crozier 1975; n=9, Tapinoma nigerrimum, Tapinoma simrothi, Crozier 1975). Integument thin and flexible, weakly sculptured. PROVENTRICULUS. Cupola slightly broader than bulb; round; with short pile; smooth, without sculpture; and without phragma. Bulb exposed in lateral view. Longitudinal muscle No. 1 present. Occlusory tract absent.

Queen
HEAD. Vertex convex to weakly concave. Compound eyes relatively anterior on head. Antennae 11 or 12 segmented (probably also 8, see worker description). Scape short, surpassing the vertex by less than one-half scape length. Anterolateral clypeal margin even with the mediolateral region. Anteromedial clypeal margin variable, either entire (without a central notch or concavity of any type) with a broad, shallow concavity, or with a distinct, central notch separated from the general outline of the margin by distinct, angular comers. Anterior clypeal setae 4-10; short, less than twice the maximum scape diameter to about the same length as the closed mandibles; straight to moderately curved ventrally. Posterior clypeal margin posterior of the anterior posterior 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 4-9 teeth and 0-12 denticles. Apical tooth slightly longer than the subapical tooth. Basal angle indistinct, with a relatively uninterrupted curve between the two margins and without a distinct tooth or angle. Basal margin varying from denticulate distally, smooth proximally to denticulate along entire surface. MESOSOMA. Posteroventral pronotum lateral, rounded or angled. Episternal suture complete. Mesopleural process absent. Anteromedial mesosternum even with the lateral regions. Axilla parallel or absent dorsally (when present, entire). Anterior axillar suture when present straight. Declivitous and dorsal faces of propodeum convex; dorsal face shorter than the declivitous face. Propodeal angle distinct. Propodeal suture absent. Mesosomal spines and tooth absent. Erect mesoscutal hairs 0- 20; when present short, less than twice the maximum scape diameter. Propodeal spiracle lateral and ventral ofthe propodeal dorsum. Hind tibial spur with well developed barbules along entire inner surface (except extreme base). WINGS. Radial cell closed. Fore wing with 1-2 cubital and 0-1 discoidal cells. Hind wing with 1-2 cells. PETIOLE. Scale reduced or absent; when present, ridged and with a distinct angle dorsally; strongly inclined anteriorly and with the anterior face much shorter than the posterior face. Venter with a slight to well developed lobe. GASTER. First segment projecting anteriorly and concealing the petiole in dorsal view and with a groove or indentation for the reception ofthe entire height ofthe petiole. Fifth tergite ventral, gaster with 4 apparent tergites. Gastral compression dorsoventral. Fourth sternite flat across entire posterior border.

Male
HEAD. Inner margin of eye entire, flat. Antennae 13 segmented (probably also with fewer segments, see worker description). Scape length much ionger than the length of funicular segments 1 +2+3 and exceeding the vertex. 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 clypeal margin variable, either entire (without a central notch or concavity of any type) or with a distinct, central notch separated from the general outline of the margin by distinct, angular corners. Anterior clypeal setae 4; varying from short (about as long as the maximum diameter of the scape) to about the same length as the closed mandibles; straight. 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. 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 at the apical extreme of segment 4. Mandible with about 8- 15 teeth and 0-3 denticles. Apical tooth slightly longer than the subapical tooth. Basal angle indistinct, with a relatively uninterrupted curve between the two margins and without a distinct tooth or angle. Basal margin smooth and without teeth or denticles. MESOSOMA. Posteroventral pronotum lateral, rounded or angled. Episternal suture present, complete. Anteromedial mesosternum even with the lateral regions. Axilla parallel or constricted medially, and entire. Anterior axillar suture straight. Declivitous and dorsal faces of propodeum convex; dorsal face shorter than the declivitous face. Propodeal angle indistinct. WI NGS. Radial cell closed. Fore wing with 1 cubital and 0-1 discoidal cells. Pterostigmal appendage absent. Hind wing with 0, 1 or 2 cells. PETIOLE. Scale reduced; ridged and with a distinct angle dorsally; strongly inclined anteriorly and with the anterior face much shorter than the posterior face. Venter with a slight to weakly developed lobe. Attachment to gaster narrow. GASTER. First segment projecting anteriorly and sometimes concealing the petiole in dorsal view, and with a groove or indentation for the reception of the entire height of the petiole. GENITALIA. Pygostyles present. Posterior margin of subgenital plate concave. Paramere divided by a membranous region (but only weakly in some species). Digitus with a down-turned tip. Cuspis absent. Ventral lobe of volsella present as concave lobe. Aedeagus with ventral teeth.

Larva
Shape dolichoderoid. Protuberances present as a single boss on posterior of body. Body hairs sparse; simple; short. 9 spiracular pairs. Antennae short.