Paratrechina

This genus contains two species, the widely distributed pest species Paratrechina longicornis and the relatively rare African species Paratrechina zanjensis.

Identification
Mandible with 5 teeth; maxillary palps 6-segmented; labial palps 4-segmented; erect setae on dorsum of head randomly placed; scapes lacking erect hairs; abundant erect setae on legs and dorsum of mesosoma. Eyes well developed and convex, surpassing outline of head in full frontal view, placed midlength and laterally on head. Dorsal mesosomal setae arranged loosely in pairs; propodeum lacking erect setae; propodeum with a low-domed dorsal face; overall mesosoma shape long and slender. (LaPolla et al. 2010)

Key to Prenolepis Group Genera

Distribution
Paratrechina longicornis has been spread by humans and obtained a pantropical distribution. It is also found in temperate climates, largely through establishing itself in buildings and other artificial environments such as greenhouses. (Wetterer et al., 1999, Wetterer 2008). It is likely that this species arose in South-east Asia but this has yet to be confirmed (LaPolla et al., 2013; Wetterer, 2008).

Nomenclature

 *  PARATRECHINA [Formicinae: Plagiolepidini]
 * Paratrechina Motschoulsky, 1863: 13. Type-species: Paratrechina currens (junior synonym of Formica longicornis), by subsequent designation of Wheeler, W.M. 1911f: 170.
 * Paratrechina junior synonym of Prenolepis: Dalla Torre, 1893: 177; Wheeler, W.M. 1922a: 940.
 * Paratrechina revived from synonymy: Emery, 1925b: 216.

LaPolla et al (2013) - Monomorphic, medium sized (2.1–3.2 mm in total length) formicine ants; brown to dark brown in color, with lighter mandibles, antennae (especially funicular segments towards tips) and legs (especially distal portion of tibiae and tarsi). Head with medially erect macrosetae roughly paired, extending through the medial portion of clypeus. Cuticle on the head smooth and shining, with faint shagreenate sculpture, especially towards the posterior margin. Antennae 12 segmented; scapes very long, with scape index above 180, usually above 200 (SI 183–220). Scapes with a dense layer of pubescence. Head is distinctly longer than wide, with cephalic index below 100 (CI 71-94); posterolateral corners rounded, with straight posterior margin. Eyes large relative to head width (REL2 greater than 35); eyes distinctly convex, extending beyond head margin in full frontal view; three small but distinct ocelli present. Mandibles typical for Prenolepis genus-group (Fig. 9), with 5 teeth; mandalus large and anteriorly placed; palps very long (0.70–0.75 mm); palp formula 6:4; segments 3-6 are longest (numbered from basal segment (1) to apical segment (6). Mesosoma distinctly elongated; in profile pronotum and mesonotum long; propodeal dorsal face either nearly flat or moderately convex (Figs 2, 5); propodeum without macrosetae, anteriorly occasionally with a sparse layer of pubescence; pronotal setal count 5–10 (both sides of notum); mesonotal setal count 4-8 (both sides of notum). Petiole cuneate, broadly rounded dorsally, with much longer posterior face and not surpassing the height of the propodeum. Legs distinctly long (profemur length 0.6–1.0 mm). Gaster robust, covered in abundant erect macrosetae.