Pristomyrmex Mayr

Eguchi, K., Viet, B. T. & Yamane, S., 2011, Generic synopsis of the Formicidae of Vietnam (Insecta: Hymenoptera), Part I - Myrmicinae and Pseudomyrmicinae., Zootaxa 2878, pp. 1-61 : 25

Pristomyrmex Mayr , 1866

Taxonomy. The genus Pristomyrmex is assigned to the tribe Myrmecinini together with Acanthomyrmex, Myrmecina and Perissomyrmex (Bolton 2003). The genus was recently revised by Wang (2003). Workers of Vietnamese species have the following features.

Worker monomorphic; head in full-face view rounded, or rarely subtrapezoidal (as in P. profundus); frontal lobe reduced or vestigial; frontal carina usually developed; antennal scrobe absent or indistinct, but rarely well developed (as in P. profundus); anterior clypeal margin with three or more denticles; median clypeal seta absent; lateral portion of clypeus reduced; posteromedian portion of clypeus broadly inserted between frontal lobes; antenna 11-segmented with distinct 3-segmented club; eye medium sized; masticatory margin of mandible almost vertical to basal margin, 3-, 4- or 5-toothed; mesosoma short and high; promesonotum not domed, but rarely raised above anterodorsal border of propodeum (as in P. profundus), unarmed or armed with a pair of humeral teeth or spines; promesonotal suture absent dorsally; anterior part of mesopleuron forming a flange projecting over basal part of fore coxa; metanotal groove usually absent, but rarely marked weakly (as in P. profundus); propodeum armed with a pair of teeth or spines; propodeal lobe triangular, blunt-triangular, or semicircular, but rarely absent (as in P. profundus); petiole with peduncle and node; postpetiole relatively short and high.

The worker of Pristomyrmex is similar to the minor worker of Acanthomyrmex (for distinguishing characters see under Acanthomyrmex ).

Vietnamese species. Five species have been recognized by us from Vietnam: profundus Wang [= sp. eg-4] (Phu Quoc); punctatus (F. Smith) [= sp. eg-1] (Ba Be, Pu Mat, Tam Dao); rigidus Wang [= sp. eg-2; = sp. 20 of SKY: Eguchi et al. 2005] (Ba Vi, Tay Yen Tu, Van Ban); sulcatus Emery [= sp. eg-5; = sp. 13 of SKY: Eguchi et al. 2005] (Ba Vi, Cuc Phuong, Phu Quoc, Pu Mat, Tay Yen Tu, Van Ban); sp. eg-3 [cf. occultus Wang; = sp. 16 of SKY: Eguchi et al. 2005] (Tam Dao).

Bionomics. The thelytokous Pristomyrmex punctatus is nomadic, but the other Vietnamese species live in rather stable nests in rotting twigs and wood fragments and under stones. The colony size of Vietnamese species, except P. punctatus , is relatively small; colonies consisting of less than 100 workers may produce reproductives.