Bioacoustics of Plectroctena

Large or medium-sized black or castaneous ants, with shining surface, sparsely punctate. Worker monomorphic, with large, rectangular and rather flat head, with small, flat, anteriorly situated eyes. Clypeus very short, its anterior border straight in the middle, emarginate on each side at the mandibular insertion, apparently not extending back between the frontal carinae, the latter overhanging the clypeus and forming with the front an elevated lobe, longitudinally sulcate in the middle. Mandibles long, linear, feebly curved, with a deep narrow furrow running nearly their full length on the dorsal surface, their tips blunt, the inner margin armed with a strong tooth at the basal third and another obtuse tooth, sometimes indistinct, between the latter and the tip. Antennae 12-jointed, the funiculi somewhat thickened towards their tips, the first joint shorter than the second. Thorax large and depressed, premesonotal suture distinct, mesoepinotal suture obsolete, epinotal declivity marginate on the sides. Petiole with a laterally compressed node, with the anterior and posterior surfaces vertical in profile, the dorsal surface horizontal. Constriction between the postpetiole and gaster pronounced, with well-developed stridulatory surface. Gaster short, formed largely by the first segment. Median spurs of middle and hind tibiae large and pectinated, lateral spurs lacking. Female winged, apterous or ergatomorphic, larger than the worker but otherwise similar. Eyes and ocelli small. Anterior wings with a discoidal cell, two cubital cells and the radial cell closed. Male about the size of the worker. Frontal carinae short, erect, closely approximated, bringing the insertions of the antennae close together. Antennal funiculi filiform, their first joint very short; scapes stout, shorter than the second funicular joint. Mandibles small, linear, parallel-sided, edentate, with rounded tips. Mesonotum with distinct Mayrian furrows; scutellum longitudinally grooved in the middle. Genitalia retracted; pygidium terminating in a blunt or truncated point. Wings short.