A mutualist with plants in the genus Triplaris. The ants patrol and aggressively defend the plant they nest in from intruders.
Ward (1999) - Workers and queens of P. dendroicus and Pseudomyrmex triplarinus can be separated from all other Triplaris-inhabiting Pseudomyrmex by the longer legs and tendency towards a broader head. P. dendroicus can be distinguished from P. triplarinus by the worker characters mentioned above and in the key. Queens of the two species are more distinct, those of P. dendroicus being absolutely larger (queen HW 1.72–2.01 and queen HL 1.82–2.12 compared with HW 1.46–1.60 and HL 1.60–1.73 in P. triplarinus) and having the mandible more modified (with a strong basal incision, and more marked deformation of the upper surface of the mandible).
Widely distributed in the western Amazon basin.
Distribution based on Regional Taxon Lists
Distribution based on AntMaps
Distribution based on AntWeb specimens
Check data from AntWeb
Ward (1999) - P. dendroicus is a strict Triplaris associate that co-occurs with Pseudomyrmex triplarinus and Pseudomyrmex triplaridis at some localities. The workers prune vegetation around the host tree, leaving a cleared area at the base of the tree (Ule, 1906b). Davidson et al. (1988) present experimental evidence that this behaviour reduces the invasion success of dominant (and generalist, non-mutualistic) neighbouring ants such as Crematogaster. Additional information on the biology of P. dendroicus is contained in papers by Ule (1906b, 1907), Wheeler (1942), Schremmer (1984) and Davidson et al. (1988, 1989). Schremmer’s investigations of P. triplarinus from Villavicencio, Colombia refer to P. dendroicus, while his observations of P. triplarinus from Since, Colombia represent another species, Pseudomyrmex mordax. Most museum specimens of P. dendroicus are labeled as coming from “Triplaris” (unidentified to species) but some collections are associated specifically with Triplaris americana Linnaeus, including those of Brandbyge, Davidson, Toft, Ule and Ward (part).
The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- dendroicus. Pseudomyrma dendroica Forel, 1904c: 40 (w.m.) BRAZIL. Combination in Pseudomyrmex: Kempf, 1961a: 408. Junior synonym of triplarinus: Kempf, 1961a: 408. Revived from synonymy and senior synonym of emarginata: Ward, 1989: 436. See also: Ward, 1999b: 490.
- emarginata. Pseudomyrma dendroica var. emarginata Forel, 1904e: 684 (w.q.) BRAZIL. Junior synonym of triplarinus: Kempf, 1961a: 408; of dendroicus: Ward, 1989: 436.
Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.
Ward (1999) - Measurements (n=34). HL 1.09–1.55, HW 1.07–1.51, MFC 0.126–0.196, LHT 0.92–1.36, CI 0.94–1.04, REL 0.40–0.46, REL2 0.41–0.45, FCI 0.11–0.14, SI 0.42–0.48, FLI 1.74–2.24, FI 0.35–0.40, PLI 0.70–0.85, PWI 0.72–0.86, PPWI 1.29–1.76.
Similar to Pseudomyrmex triplarinus (q.v.) except as follows. Posterior margin of head more markedly concave (frontal view). Frontal carinae better separated, on average. Scape tending to be longer in relation to HL. Petiole less expanded posterolaterally. Subpetiolar process generally subrectangular or fin-shaped, and pointing posteroventrally. Punctulate sculpture slightly denser on upper third of head, on average. Standing pilosity longer but less common, MSC 7–53, HTC 1–11, absent from the posterior margin of the head; erect hairs on the petiole and postpetiole tending to be more notably curved. Head (except for mandibles, scapes and frontoclypeal complex) brown to dark brown and nearly always contrasting with the lighter-coloured mesosoma.
Ward (1999) - Lectotype worker, Rio Purus, Brazil (A. Goldi) (Musee d'Histoire Naturelle Genève) [Examined].
- Forel, A. 1904d. Miscellanea myrmécologiques. Rev. Suisse Zool. 12: 1-52 (page 40, worker, male described)
- Kempf, W. W. 1961a. Estudos sôbre Pseudomyrmex. III. (Hymenoptera: Formicidae). Stud. Entomol. 4: 369-408 (page 408, Combination in Pseudomyrmex, and junior synonym of triplarinus)
- Ward, P. S. 1989a. Systematic studies on pseudomyrmecine ants: revision of the Pseudomyrmex oculatus and P. subtilissimus species groups, with taxonomic comments on other species. Quaest. Entomol. 25: 393-468 (page 436, Revived from synonymy, and senior synonym of emarginata)
- Ward, P. S. 1999b. Systematics, biogeography and host plant associations of the Pseudomyrmex viduus group (Hymenoptera: Formicidae), Triplaris- and Tachigali-inhabiting ants. Zool. J. Linn. Soc. 126: 451-540 (page 490, see also)