Pristomyrmex levigatus

This species occurs in rainforest and has been collected in a litter sample.

Identification
Wang (2003) – Worker. Masticatory margin of mandible lacking a diastema and possessing four teeth, of which the third tooth, counting from the apex, smallest; HW 0.62-0.78, HL 0.64-0.78; eyes with five to eight ommatidia in the longest row; pronotum unarmed ; propodeum with a pair of teeth or short spines; petiole with a lateral longitudinal carina on each side; subpetiole lacking a pinlike long process; dorsal surfaces of head and alitrunk smooth and shining.

Pristomyrmex levigatus appears to be a basal species within the levigatus group. Many species, such as P. acerosus, P. boltoni, P. inermis, P. largus, P. lucidus, P. mandibularis, P. minusculus, P. obesus, and P. simplex, may have evolved from a P. levigatus-like ancestor. The workers of these species are separable from those of P. levigatus as follows: P. levigatus differs from both Pristomyrmex simplex and Pristomyrmex obesus by lacking foveolate punctures on the dorsal surfaces of the alitrunk and the head between the frontal carinae. In P. levigatus, the eyes are larger, usually containing five to eight ommatidia in the longest row but two to three in Pristomyrmex boltoni. Pristomyrmex levigatus is smaller (HW < 0.80, HL < 0.80) than Pristomyrmex largus and Pristomyrmex lucidus (HW > 0.90, HL > 0.90). Pristomyrmex minusculus bears a pair of pronotal teeth that are not seen in P. levigatus. A pair of propodeal teeth or short spines are present in P. levigatus, but absent in Pristomyrmex inermis. Pristomyrmex levigatus possesses a longitudinal ruga on each side of the petiole node that is not seen in Pristomyrmex mandibularis. Finally, the subpetiole of P. levigatus does not have a pinlike long process that is distinct in Pristomyrmex acerosus.

Key to Pristomyrmex workers

Distribution based on Regional Taxon Lists
Indo-Australian Region: Micronesia (Federated States of), New Guinea, Philippines, Solomon Islands, Wallis and Futuna Islands.

Nomenclature

 *  levigatus. Pristomyrmex levigatus Emery, 1897c: 583, pl. 15, fig. 24 (w.) NEW GUINEA. Wang, M. 2003: 501 (q.m.). Senior synonym of mendanai: Wang, M. 2003: 499.
 * mendanai. Pristomyrmex mendanai Mann, 1919: 341 (w.) SOLOMON IS. Junior synonym of levigatus: Wang, M. 2003: 499.

Worker
Wang (2003) - TL 2.36- 2.96, HL 0.64-0.78, HW 0.62-0.78, CI 96-106, SL 0.50-0.65, SI 78- 89, EL 0.12-0.16 (very rarely 0.10), PW 0.41-0.52, AL 0.54-0.75, PPW 0.20-0.22, PPL 0.14-0.18, PPI 122-143 (n = 30).

Mandibles usually smooth and shining but with a few fine longitudinal rugae in some specimens. A broad-based triangular short tooth present about midway on the basal margin of the mandible. Frontal area concave, usually unsculptured, but sometimes with a weak median carina. Clypeus flat, unsculptured, smooth, and shining; its anterior margin with a median denticle and two lateral teeth, but sometimes the median tooth is weak or absent. Ventral surface of clypeus lacking any rugae or toothlike prominences. Palp formula 1,3. Frontal carinae distinct, extending to the level of the posterior margins of eyes. Scrobal impressions shallow, present lateral to the frontal carinae. Frontal lobes weak so that the antennal articulations are almost entirely exposed. Antennal scapes, when lying on the head, close to the occipital margin. Eyes moderately sized, with five to eight ommatidia in the longest row. Dorsum of alitrunk in dorsal view flat in the lectotype but convex in some specimens. Pronotum unarmed or at most with blunt tubercles, lacking teeth or spines. Propodeum with a pair of triangular teeth or short spines that are slender, slightly incurved at their apices in the lectotype. Metapleural lobes subtriangular or rounded. Petiole node in profile nodiform with the anterodorsal angle higher than the posterodorsal; its anterior peduncle about as long as the node. Subpetiole with a narrow long flange. In dorsal view, the dorsum of petiole node transoval and broader than long. Postpetiole in profile higher than long, with a rounded dorsum, in dorsal view somewhat transverse-rectangular and broader than long. Dorsum of head smooth and shining but sometimes with a few foveolate punctures bordering the frontal carinae; sometimes a few foveolate punctures present on the genae and around the eyes. Dorsum of alitrunk unsculptured, smooth, and shining. Petiole and postpetiole smooth and shining, each with a longitudinal carina on each side that separates the tergite from the sternite. Gaster unsculptured. Dorsum of head with numerous erect to suberect hairs. Dorsum of alitrunk with some erect or suberect hairs. Dorsal surfaces of petiole node and postpetiole usually with one to two pairs and one to three pairs of hairs, respectively. A few hairs present at the base of the first gastral tergite. A few pairs of forward-projecting hairs present near the anterior clypeal margin. Scapes and tibiae with erect to sub erect short hairs. Color golden-brown or reddish-brown.

Queen
Wang (2003) - TL 2.92-3.34, HL 0.74-0.75, HW 0.76-0.81, CI 101-108, SL 0.60-0.6.5, SI 79-83, EL 0.18-0.19, PW 0.54-0.66, AL 0.80-0.92, PPW 0.23-0.26, PPL 0.18-0.20, PPI 128-133 (n = 5).

Generally similar to worker, except for normal caste differences. Propodeal armaments tuberculate or denticulate, slightly shorter than those in the conspecific worker.

Male
Wang (2003) - Two male specimens, together with 13 workers and two queens, collected in New Guinea (Nadzab, #1083) by E. O. Wilson, constitute a series; each of the two males was originally mounted together with a worker or with a worker and a queen on the same pin: TL 2.48, 2.54; HL 0.50, 0.51; HW 0.53, 0.53; CI 105, 106; SL 0.16, 0.18; SI 30, 34; HWE 0.63, 0.64; EL 0.23, 0.25; PW 0.60, 0.63; AL 0.82,0.84; PP\V 0.18,0.19; PPL 0.15, 0.16; PPI 119, 120 (n = 2).

Head, including the eyes, broader than long. Clypeus lacking a median longitudinal carina; anterior clypeal margin rather straight. Frontal carinae reaching the level of the posterior margins of antennal insertions. Mesoscutum lacking distinct notauli and parapsidal furrows. Scuto-scutellar sulcus with nine narrow longitudinal ridges. Propodeum weakly tuberculate, lacking teeth or spines. Metapleural lobes with a blunt or somewhat rounded apex. Middle and hind tibiae without any spurs. Petiole node in profile low, nodiform, having an anterior face and a long anterior peduncle. Postpetiole in profile low and rounded dorsally, in dorsal view subrectangular and broader than long. Dorsum of head smooth and shining, but frontal area with a median longitudinal carina. Dorsal alitrunk generally smooth and shining, except for those marked sutures. Dorsal surfaces of petiole and postpetiole smooth and shining. Gaster unsculptured. All dorsal surfaces with abundant rather long hairs. Legs and scapes with numerous erect or suberect short hairs. Color blackish-brown. Wings infuscated.

Type Material
Wang (2003):

Lectotype worker, New Guinea: near Friedrich-Wilhelmshafen et Berlinhafen (Biro), here designated, [examined].

Pristomyrmex mendanai Mann, 1919: 341. Two syntype workers, Solomon Is.: Santa Cruz Is., Graciosa Bay, 19.v.- 24 .xi.1916 (W. M. Mann)  [examined].