Appears to be associated exclusively with Acacia allenii, a forest species.
Ward (1993) - P. particeps is obviously a very close relative of the allopatric Pseudomyrmex nigrocinctus, but there are consistent differences between the two in eye size and color which exceed the limits of variation seen throughout the much wider range of P. nigrocinctus. Workers in the type series of P. particeps also have more elongate heads than those of P. nigrocinctus but this distinction is not seen in other samples. Differences between queens of the two species are more striking with the two known queens of P. particeps having more elongate heads (CI 0.61, compared with 0.67-0.72 in a sample of 13 P. nigrocinctus queens) and longer metatibiae relative to head width (LHT/HW 1.12 versus 0.97-1.07 in P. nigrocinctus). Additional alates of P. particeps are needed to confirm these differences and the apparent distinctions in male genitalia (see male key).
A rare species known only from the Osa Peninsula and one adjacent locality, in Costa Rica.
Distribution based on Regional Taxon Lists
Distribution based on AntMaps
Distribution based on AntWeb specimens
Check data from AntWeb
The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- particeps. Pseudomyrmex particeps Ward, 1993: 146, figs. 14, 23, 54, 57, 72 (w.q.m.) COSTA RICA.
Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.
measurements (n=12). —HL 0.93-1.10, HW 0.77-0.83, MFC 0.037-0.050, CI 0.75-0.84, REL 0.44-0.48, REL2 0.55-0.60, OOI 1.47-1.96, VI 0.65-0.75, FCI 0.048-0.062, SI 0.45-0.49, SI2 0.78-0.83, NI 0.53-0.62, PLI 0.58-0.66, PWI 0.55-0.60, PPWI 1.03-1.26.
Very similar to Pseudomyrmex nigrocinctus (q.v.) except as follows. Eyes longer(REL2 0.55-0.60, EL/LHT 0.59-0.64). Front of head more strongly shining. Medium to dark brown; gaster uniformly dark brown or black; mandibles, fronto-clypeal complex, and appendages lighter brown.
Holotype worker. —COST A RICA, Puntarenas: Rincon, Peninsula Osa, 3.iii.1965, D.H. Janzen #III (Los Angeles County Museum of Natural History). HW 0.83, HL 1.10, EL 0.50, PL 0.50, PH 0.31.
Paratypes. —Same data as holotype: series of 82 workers, 14 males, one queen (American Museum of Natural History, The Natural History Museum, California Academy of Sciences, Graham B. Fairchild Museo de Invertebrados, Instituto Nacional de Biodiversidad, John T. Longino Collection, LACM, Museum of Comparative Zoology, Museu de Zoologia da Universidade de Sao Paulo, Philip S. Ward Collection, University of California, Davis, National Museum of Natural History).
- Ward, P. S. 1993. Systematic studies on Pseudomyrmex acacia-ants (Hymenoptera: Formicidae: Pseudomyrmecinae). J. Hym. Res. 2: 117-168 (page 146, figs. 14, 23, 54, 57, 72 worker, queen, male described)
- Ward, P.S. 2017. A review of the Pseudomyrmex ferrugineus and Pseudomyrmex goeldii species groups: acacia-ants and relatives (Hymenoptera: Formicidae). Zootaxa 4227: 524–542 (doi: 10.11646/zootaxa.4227.4.3).