Eurhopalothrix bolaui (Mayr, 1870)

Longino, John T., 2013, A review of the Central American and Caribbean species of the ant genus Eurhopalothrix Brown and Kempf, 1961 (Hymenoptera, Formicidae), with a key to New World species, Zootaxa 3693 (2), pp. 101-151 : 113-114

Eurhopalothrix bolaui (Mayr, 1870)

( Figs 2 A, 8B, 12A, 15, 35)

Rhopalothrix bolaui Mayr, 1870: 415 (footnote). Holotype queen: Suriname [NMW] (not examined). Combination in Eurhopalothrix: Brown & Kempf, 1960: 210 .

Rhopalothrix (Rhopalothrix) amoena Mann, 1922: 39 . Syntype worker, queen: Honduras, La Ceiba, Cecilia [USNM, MCZC, BMNH] (AntWeb image of BMNH syntype worker examined). Synonymy by Brown & Kempf, 1960: 210.

Geographic range. Guatemala to Amazonian Brazil.

Description. Worker. HW 0.56–0.70, HL 0.58–0.67, SL 0.35–0.39, SLL 0.03–0.05, CI 96–105, SLI 9–12 (n=11). Labrum as in Fig. 2 A, anterolateral gibbosities of basal portion developed as sharply right-angled, ventrally-directed teeth, apical portion elongate, flexed dorsally, distinctly bilobed at apex; apex with a fringe of capitate translucent setae; mandible triangular, dorsal surface convex, mostly punctate, smooth and shining at apex, rounding into ventral surface; interior surface concave, smooth and shining; masticatory margin a single row of 11 flattened acute triangular teeth; scape with weakly developed basal lobe; scrobe deep, sharply delimited dorsally and ventrally, abutting deep antennal socket; surface of scrobe weakly foveolate; eye with about 6 ommatidia across greatest diameter; clypeus approximately planar, uniformly punctate, dull; sides of head above eyes weakly angulate; surface of face uniformly convex, punctate, puncta smaller anteriorly; occipital carina indistinct; undersurface of head uniformly punctate; postgenal suture a well-developed longitudinal trough, darker than surrounding cuticle.

Promesonotal profile low, somewhat flat-topped, with short posterior face that meets flat dorsal face of propodeum at obtuse angle; metanotal groove not impressed; dorsal and posterior faces of propodeum distinct, meeting at obtuse angle, dorsal face subequal in length to posterior face; propodeal spine laminar, translucent, triangular with broad base, apex acute, inner surface concave, ventral margin sloping down to gradually round into short, broad infradental lamella that extends down posterior face to propodeal lobe; propodeal spiracle small, directed somewhat posteriorly; mesosoma except posterior face of propodeum punctate; posterior face of propodeum minutely punctulate; promesonotum and dorsal face propodeum with large confluent puncta; mesopleuron and side of propodeum with smaller, more widely-spaced, less conspicuous puncta; no transverse carinae between bases of propodeal spines.

Petiolar peduncle joins anterior face of petiolar node at rounded obtuse angle; anterior face of node meets sloping dorsal face at rounded right angle; posterior face of node short; ventral margin of petiole with pronounced, acute anteroventral tooth; postpetiole low and broad, with a shallow longitudinal sulcus dorsally; first gastral sternite lacking anterior sagittal keel; petiole, postpetiole, first gastral tergite covered with dense, small, confluent puncta; first gastral sternite similar, but puncta slightly larger and with discernible interspaces.

Dorsal surface of scape covered with uniform short, appressed, flattened setae; leading edge of scape with projecting setae, short and strongly curved near apex, becoming longer and less curved toward base, with long straight seta on basal lobe; ground pilosity on clypeus obsolete; posterior half of face with ground pilosity of dense appressed setae similar to those on dorsal scape, grading to smaller appressed setae on anterior portion of face and onto frontal lobes; undersurface of head with abundant ground setae like those on dorsal face; projecting specialized setae strongly spatulate, pompon-like, much larger than ground pilosity and highly differentiated from it, full complement 18, with curved anterior row of 8, transverse median row of 4, and posterior row of 6 on vertex margin; ground setae similar to those on face abundant on promesonotal dorsum, dorsal half of propodeal spines, very dense on dorsa of petiolar node and postpetiole, moderately abundant on first gastral tergite; 3 pairs projecting spatulate setae on promesonotum; legs with dense, strongly flattened, fully appressed setae on apices of femora, posterior face of foretibia, entire midtibia, anterior face of hindtibia, somewhat sparser on other surfaces; apices of tibiae ringed with larger spatulate setae; basitarsus and remaining tarsomeres with abundant, strongly spatulate setae; two large spatulate setae on hind margin of dorsal face of petiolar node; row of 4 spatulate setae on hind margin of postpetiole, median pair smaller than lateral pair; specialized setae of first gastral tergite spatulate, full complement 4 pairs in two longitudinal rows.

Color orange brown.

Queen. HW 0.58–0.74, HL 0.61–0.75, SL 0.36–0.45, SLL 0.03–0.05, CI 96–99, SLI 9–13 (n=5). Similar to worker in most respects; ocelli present; compound eye much larger than worker eye; anepisternum separated from katepisternum by U-shaped groove; metapleuron separated from propodeum by broad U-shaped groove; puncta fading on anterodorsal katepisternum, leaving small smooth patch; pronotum with 1 pair spatulate setae; mesoscutum with 6 setae, medial 4 straight, erect, narrowly clavate, lateral pair spatulate; axilla with spatulate seta; scutellum with 1 pair spatulate setae; first gastral tergite with number and arrangement of erect setae similar to worker.

Biology. This species is more likely to be found in second growth wet forest habitats than primary forest. It is a lowland species, occurring from sea level to 800 m elevation in Central America. One examined queen from Venezuela was found at 1350 m, in montane forest. Most specimens are from Winkler and Berlese samples of sifted litter and rotten wood from the forest floor. However, on multiple instances workers and in one case a dealate queen have been found by searching beneath loose bark of rotten wood.

Comments. A worker and queen (probable nestmates) from Osa Peninsula, Costa Rica, are considerably smaller than other Central American material. A queen from Venezuela is larger, darker, and with more roughened face sculpture compared to Central American queens.

Figures

FIGURE 2. Eurhopalothrix labra. A. E. bolaui (Nicaragua, CASENT 0619922). B. E. semicapillum (Costa Rica, CASENT 0639342). C. E. ortizae (Costa Rica, LACM ENT 143281). D. E. gravis (Costa Rica, INB 0003212299). E. E. sepultura (Mexico, CASENT 0639334). F. E. mabuya (Cuba, CASENT 0630193). G. E. xibalba (Costa Rica, INB 0003698926). H. E. floridana (USA, LACM ENT 143276). I. E. cimu (Cuba, CASENT 0639337). A – H are dissected labra imaged in fluid. I is dry-mounted specimen, basal portion is not visible, and maxilla are visible in background. With the exception of E. cimu, specimen codes are for dry-mounted specimens from the same series, not the dissected specimen. Images are not to scale.