Perissomyrmex bidentatus

Xu and Zhang (2012) - In a large sample, 30 individuals were collected from a nest constructed inside top soil. Among the 30 individuals, one queen (3.2%), two soldiers (6.7%), and 27 workers (90%) were involved. In addition, four workers and one queen were collected from ground and soil samples, and two winged females were collected from ground and tree crown samples respectively. The winged females were collected from October 10 to 19. The collection data show that the species is monogynous and nests in soil; workers are weakly dimorphic and forage on the ground; the soldier caste only occupies a small percentage; nuptial flight occurs on the plants and ground; and the nuptial flight time is mid-October in Hengduan Mountains of southwestern China. Collected from forest habitats.

Distribution based on Regional Taxon Lists
Palaearctic Region: China.

Nomenclature

 *  bidentatus. Perissomyrmex bidentatus Zhou & Huang, 2006: 192, figs. 4  6 (w.) CHINA. Xu & Zhang, 2012: 151 (s.q.). Senior synonym of emarginatus: Xu & Zhang, 2012: 150.
 * emarginatus. Perissomyrmex emarginatus Ogata & Okido, 2007: 359, figs. 14, 16a-c, 17a (w.q.) CHINA. Junior synonym of bidentatus: Xu & Zhang, 2012: 150.

Worker
Xu and Zhang (2012) - TL 3.7-4.1, HL 1.00-1.20, HW 1.00-1.20, CI 95-100, SL 0.83-0.93, SI 75-88, ED 0.13-0.15, PW 0.58-0.68, AL 1.08-1.25 (11 individuals measured). Well conform to the measurements, description, and images of the species, but median teeth of anterior clypeal margin are variable, which show a normal apically obliquely truncated state or weakly apically bifid state.

Soldiers. TL 4.3-4.4, HL 1.25-1.33, HW 1.28-1.38, CI 102-104, SL 0.90-0.95, SI 67-71, ED 0.16-0.20, PW 0.70-0.73, AL 1.23-1.25 (two individuals measured). Similar to worker caste, but body relatively larger, head proportionally larger. Occipital margin more deeply concaved. Teeth on masticatory margin of mandibles moderately reduced and blunt. Median teeth of anterior clypeal margin broad and truncated at apices, with shallow notch between teeth. Antennae relatively short, apices of scapes just reaching occipital corners.

Morphological variations. The morphology of the clypeus shows rich variations in worker, soldier, and queen castes. In the worker caste, the median teeth of anterior clypeal margin may be either apically obliquely truncated (60% individuals) or weakly apically bifid (40% individuals). In the two soldiers obtained, the median teeth are apically truncated and short, which is different from the worker caste. In the queen caste and winged females, the median teeth are apically truncated in three individuals (75%), or apically obliquely truncated in one winged female (25%).

Queen
Xu and Zhang (2012) - TL 4.6-5.0, HL 1.18-1.25, HW 1.23-1.33, CI 100-106, SL 0.90-0.96, SI 68-76, ED 0.18-0.23, PW 0.83-0.95, AL 1.35-1.45 (four individuals measured). Similar to worker caste, but body relatively larger, head proportionally larger. Median teeth of anterior clypeal margin variable, showing a normal apically truncated state (as in soldier caste) or apically inward curved state (as the normal state in worker caste). Antennae relatively short, apices of scapes just reaching to occipital corners. Vertex with three ocelli. Mesosoma winged or dealate, massive in volume. In profile view, mesonotum high, weakly convex and sloped down backward. Mesopleuron with oblique furrow. Metanotum very short, overhung by scutellum. Dorsum of propodeum weakly concave, steeply sloped backward. Propodeal spines straight, slightly longer than dorsum. Declivity weakly concave, about as long as spines. In dorsal view, scutum of mesonotum without longitudinal furrows, posterior margin weakly convex. Anterior margin of scutellum very bluntly angled, posterior margin rounded. Propodeal spines strong and very obviously curved inward. Ocellus area, anterior and lateral areas of mesonotal scutum black.