Pseudomyrmex capillatus

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Pseudomyrmex capillatus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Pseudomyrmecinae
Genus: Pseudomyrmex
Species group: elongatulus
Species: P. capillatus
Binomial name
Pseudomyrmex capillatus
Ward & Branstetter, 2022

Pseudomyrmex capillatus is thus far known only from Jalisco and Colima in western Mexico. In tropical dry forest at Estación Biología Chamela two nest series were collected by P.S.Ward, both in dead twigs of vines (the vines were 1 m apart, so the nests were likely part of a single colony), and a worker was collected foraging on low vegetation. Recorded elevations are 100 m and 365 m.

Identification

Medium-sized species (HW 0.99–1.07) with moderately elongate head (CI 0.81–0.84) and eyes (see REL and REL2 values); frontal carinae separated by slightly less than basal scape width; metanotal groove distinctly impressed; dorsal face of propodeum flat, elevated anteriorly above level of mesonotum, rounding into declivitous face, the two faces subequal in length; petiole relatively slender (PLI 0.54–0.57, PL/HL 0.54–0.56), in profile petiole with a slight anterior peduncle and with flat to convex anterodorsal face, ascending gradually to summit in the posterior half of node, then rounding into more rapidly descending posterior face; profemur slender; hind leg relatively short (LHT/HL 0.70–0.72). Head opaque, densely coriarious to coriarious-imbricate, punctulae very fine and inconspicuous. Standing pilosity common on head, mesosoma (including mesonotum and propodeum), petiole, postpetiole, and gaster (MSC 25–39, HTC 0, MTC 1–2). Body rather uniformly dark-brown, except scapes, mandibles, anterior quarter of head capsule, protibia, and protarsus, which are a contrasting light yellowish-brown.

This species is notable for the conspicuous standing pilosity that covers the entire mesosoma dorsum (Fig. 13). Such pilosity is generally restricted to 1–3 pairs of setae on the worker pronotum in other members of the P. elongatulus group. Other salient features of the P. capillatus worker are the densely sculptured and opaque head, raised dorsal face of the propodeum, and unique color pattern (see Worker Diagnosis). Surprisingly, our UCE analyses show P. capillatus to be embedded phylogenetically within Pseudomyrmex arcanus (Fig. 1), although the two are superficially quite different in appearance. Both species occur sympatrically at Estación Biología Chamela, the type locality of P. capillatus, but the Chamela sample of P. arcanus (D1651) is not sister to the two P. capillatus samples. This suggests that P. arcanus, the more widespread of the two species, is in the process of achieving allelic monophyly relative to P. capillatus, but that this has not yet gone to completion.

Keys including this Species

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: 19° to 18°.

 
North
Temperate
North
Subtropical
Tropical South
Subtropical
South
Temperate
  • Source: Ward & Branstetter, 2022

Distribution based on Regional Taxon Lists

Neotropical Region: Mexico (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.
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Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.
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Biology

Castes

Phylogeny

Relationships among Pseudomyrmex elongatulus group species based on Ward & Branstetter (2022).

Pseudomyrmex

Pseudomyrmex salvini

some Pseudomyrmex championi

some Pseudomyrmex championi

Pseudomyrmex apache

Pseudomyrmex fasciatus

some Pseudomyrmex cognatus

some Pseudomyrmex cognatus

Pseudomyrmex comitator

some Pseudomyrmex arcanus

some Pseudomyrmex arcanus

Pseudomyrmex capillatus

Pseudomyrmex veracruzensis

Pseudomyrmex nimbus

Pseudomyrmex exoratus

Pseudomyrmex ereptor

Pseudomyrmex elongatulus

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

  • capillatus. Pseudomyrmex capillatus Ward & Branstetter, 2022: 19, figs. 13, 22 (w.) MEXICO (Jalisco).

Type Material

  • Holotype Worker. MEXICO Jalisco: Est. Biología Chamela, 100 m, 19° 30′ N 105° 02′ W, 18 Dec 1987, ex dead twig of thorny vine, tropical dry forest, P. S. Ward PSW09248 (UNAM) (CASENT0863535).
  • Paratypes: series of workers, same data as holotype (CASC, CZUG, IEXA, MCZC, PSWC, UCDC, USNM).

Description

References