Forelius

Species of Forelius are ground nesters and occur in drier habitats. Nests may be under rocks or in the soil with a small crater of loose soil at the entrance. Workers forage for honeydew and arthropods on the ground or in trees. They are usually active during the warmer parts of the day and generally have a high thermal tolerance as they often forage when other ants have retreated to their nests due to the heat. Foraging is singly or in dense columns and workers characteristically move in a rapid, frenzied fashion.

Identification
Shattuck (1992) - Worker: Anterior clypeal margin with long, ventrally curved setae which are about the same length as the closed mandibles; mandibles with 5 teeth and 0-2 denticles, a distinct basal angle, and a smooth basal margin; pronotum with 2 elongate hairs (at least 1/3 longer than others on the pronotum) (rarely more), and 1 to about 14 short hairs; petiolar scale reduced and strongly inclined anteriorly, or absent; first gastral segment projecting anteriorly and concealing petiole in dorsal view (anterior base visible in some species); propodeal spiracle sometimes elongate. North and South America.

Queen: Anterior clypeal margin with moderately ventrally curved setae which are about the same length as the closed mandibles; mandibles with 5 to 6 teeth, 0 to 2 denticles, and with the basal margin smooth and without teeth or denticles; petiolar scale vertical and not inclined anteriorly; fore wing with an open radial cell and without closed discoidal cells; hind wing with 1 closed cell.

Male: Second funicular segment with a lateral bend; palp formula 5:3; pygostyles vestigial; scape approximately the same length as funicular segments 1 +2+3; anterior clypeal margin with setae which are approximately the same length as the closed mandibles; fore wing radial cell open; hind wing without closed cells.

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

An unnamed fossil species is known from Chiapas, Mexico (Totolapa amber, Miocene; Duran-Ruiz et al., 2013).

Nomenclature

 *  FORELIUS [Dolichoderinae: Leptomyrmecini]
 * Forelius Emery, 1888d: 389. Type-species: Iridomyrmex mccooki, by monotypy.
 * Forelius senior synonym of Neoforelius: Shattuck, 1992c: 87; Cuezzo, 2000: 204.
 * NEOFORELIUS [junior synonym of Forelius]
 * Neoforelius Kusnezov, 1953b: 327. Type-species: Neoforelius tucumanus, by monotypy.
 * Neoforelius junior synonym of Forelius: Shattuck, 1992c: 87; Cuezzo, 2000: 204.

Description
Shattuck (1992):

Worker
HEAD. Vertex weakly convex 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 c1ypeal margin even with the mediolateral region. Anteromedial c1ypeal margin entire, without a central notch or concavity of any type. Anterior clypeal setae 4-6 (rarely 8); about the same length as the closed mandibles; 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 (but with between 2 and about 12 elongate hairs randomly placed on gula). 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 5-6 teeth and 0-2 denticles. Apical tooth subequal in length to, to elongate and much longer than, the subapical tooth. Basal angle distinct, with a well developed tooth or angle separating the masticatory and basal margins. Basal margin smooth and without teeth or denticles. MESOSOMA. Posteroventral pronotum lateral, rounded or angled. Mesopleural process absent. Anteromedial mesosternum even with the lateral regions. Declivitous face of propodeum convex to flat; dorsal face convex, longer or shorter than the declivitous face. Propodeal angle distinct or indistinct. Mesosomal spines and tooth absent. Erect pronotal hairs 2-16 (2 (rarely more) hairs elongate (at least 1/3 longer than any other hairs on the pronotum) and the remainder short). Dorsal pro-mesonotal junction with the mesonotum slightly above, or even with, the pronotum. Metanotal groove either forming a distinct angle between the mesonotum and propodeum, or reduced to a suture and with the mesonotum and propodeum forming a continuous, uninterrupted surface. Metanotal spiracle lateral and ventral ofthe dorsal surface when viewed in lateral profile. Propodeal spiracle lateral and ventral of the propodeal dorsum (sometimes greatly elongate). Hind tibial spur with well developed barbules along entire inner surface (except extreme base). PETIOLE. Scale present or 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 well developed lobe. GASTER. First tergite projecting anteriorly and concealing the petiole in dorsal view (anterior base of pedicel visible in some species) and with a groove or indentation for the reception of the entire height of the petiole. Anterior tergosternal suture of the first segment extending laterally from the helcium in a distinct arch which extends dorsal of the dorsal helcial surface. Fifth tergite ventral, gaster with 4 apparent tergites. Gastral compression dorsoventral. Fourth sternite keel- shaped posteriorly. GENERAL CHARACTERS. Worker caste monomorphic (rarely weakly polymorphic). Chromosome number 16 (n=16, F. foetidus (= F. maccooki), Crozier 1970a}. Integumentthin and flexible, weakly sculptured. PROVENTRICULUS. Cupola much broader than bulb; round; with short pile; smooth, without sculpture; and with short, lateral phragma. Bulb partially hidden by cupola in lateral view. Longitudinal muscle No. 1 present or absent. Occlusory tract absent.

Queen
HEAD. Vertexflattoweakly 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 entire, without a central notch or concavity of any type. Anterior clypeal setae 6; about the same length as the closed mandibles; 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. 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 5-6 teeth and 0- 2 denticles. Apical tooth slightly longer than the subapical tooth. Basal angle distinct, with a well developed tooth or angle separating the masticatory and basal margins. Basal margin smooth and without teeth or denticles. MESOSOMA. Posteroventral pronotum lateral, rounded or angled. Episternal suture complete. Mesopleural process absent. Anteromedial mesosternum even with the lateral regions. Axilla parallel and entire. Anterior axillar suture straight. Declivitous face of propodeum convex; dorsal face convex, subequal in length to the declivitous face. Propodeal angle indistinct. Propodeal suture absent. Mesosomal spines and tooth absent. Erect mesoscutal hairs about 6- 30; short, less than twice the maximum scape diameter. Propodeal spiracle lateral and ventral of the propodeal dorsum. Hind tibial spur with well developed barbules along entire inner surface (except extreme base). WINGS. Radial cell open. Fore wing with 1 cubital and no discoidal cells. Hind wing with 1 cell. PETIOLE. Scale present; either rounded and forming an even arch dorsally, or ridged and with a distinct angle dorsally; vertical and not inclined anteriorly. Venter with a well developed, rounded lobe. GASTER. First segment vertical and not concealing the petiole in dorsal view and with a groove or indentation for the reception of the entire height of the petiole. Fifth tergite ventral, gaster with 4 apparent tergites. 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 at most only slightly longer than the length of funicular segments 1 +2+3, or occasionally much longer than the length of funicular segments 1 +2+3 but not exceeding the vertex. First funicular segment cylindrical or cone-shaped. Second funicular segment cylindrical and with a lateral bend. Funicular segments 2 and 3 at most twice as long as broad. Third and fourth funicular segments straight. Anteromedial clypeal margin entire, without a central notch or concavity of any type. Anterior clypeal setae 2-6; 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 5:3 (apparently 0:0 in F. go/bachi (Kusnezov 1953a)). Third maxillary palp segment subequal in length to segment 4. Fifth maxillary palp atthe apical extreme of segment 4. Mandible with 1-5 teeth and no denticles. Apical tooth elongate and much longer than the subapical tooth. Basal angle either distinct (with a well developed tooth or angle separating the masticatory and basal margins) or 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 and entire. Anterior axillar suture straight. Declivitous face of propodeum convex; dorsal face convex, longer than, to subequal in length to, the declivitous face. Propodeal angle distinct. WINGS. Radial cell open. Fore wing with 0-1 cubital and no discoidal cells. Pterostigmal appendage absent. Hind wing cells absent. PETIOLE. Scale present; rounded and forming an even arch dorsally; vertical and not inclined anteriorly. Venter with a slight or weakly developed lobe. Attachment to gaster broad. GASTER. First segment vertical and not concealing the petiole in dorsal view, smooth and without a groove or indentation. GENITALIA. Pygostyles vestigial. Digitus linear, with a slight ventral arch. Cuspis absent. Ventral lobe of volsella present as concave lobe. Aedeagus with ventral teeth.

Larva
Shape dolichoderoid. Protuberances present or absent; when present, as a single boss located mid-dorsally on second abdominal tergite. Body hairs sparse; simple; short. 9 spiracular pairs. Antennae large or short.