Eurhopalothrix megalops Longino

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 : 129-130

Eurhopalothrix megalops Longino , sp. nov.

( Figs 15 A, 24, 36)

Type material. Holotype worker: Costa Rica, Heredia: 11km SE La Virgen, 10.33333 -84.06667, ± 2km, 500 m, 12–16 Feb 2003, wet forest stream edge, Cascante refuge, pan trap (M. Pollet) [CAS, JTLC000003555].

Geographic range. Costa Rica.

Diagnosis. Mandible with single tooth row; face with 16 specialized spatulate setae; angle between anterior and dorsal faces of petiolar node obtuse; eye large, about 9 ommatidia across long axis; legs relatively long, hind tibia length about 0.6 HW. Similar to E. circumcapillum , E. ortizae , E. oscillum , E. schmidti , E. semicapillum .

Description. Worker. HW 0.74, HL 0.75, SL 0.47, SLL 0.04, CI 98, SLI 8 (n=1). Labrum similar to Fig. 2 B, anterolateral gibbosities of basal portion developed as sharply right-angled, ventrally-directed teeth, apical portion elongate, flexed dorsally, relatively narrow, with a minute notch at apex; apex with a fringe of short, non-capitate translucent setae; mandible triangular, dorsal surface convex, smooth and shining apically, grading to punctate basally, rounding into ventral surface; interior surface concave, smooth and shining; masticatory margin a single row of 11 flattened acute triangular teeth; scape with very weakly developed basal lobe; scrobe deep, sharply delimited dorsally and ventrally, abutting deep antennal socket; surface of scrobe foveolate; eye with about 9 ommatidia across greatest diameter; clypeus approximately planar, uniformly punctate, dull; sides of head above eyes moderately angulate; surface of face uniformly convex, punctate posteriorly, grading to minutely punctulate and matte anteriorly; occipital carina indistinct; undersurface of head uniformly punctate; postgenal suture a welldeveloped longitudinal trough, darker than surrounding cuticle.

Promesonotal profile evenly convex, meeting flat dorsal face of propodeum at broad 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, elongate triangular, acute, ventral margin rounding into very narrow 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; metapleural gland bulla somewhat inflated, cuticle thin, translucent, nearly smooth; 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 obtuse angle; posterior face of node short; ventral margin of petiole with short, anteroventral tooth; postpetiole low and broad, with a very feeble 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, strongly 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 of very sparse, very fine, short, fully appressed setae, inconspicuous; 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 face; projecting specialized setae spatulate, about twice as long as wide, curved, about twice as large as ground pilosity (and thus not highly differentiated from it), full complement 16, with curved anterior row of 8, transverse median row of 4, and posterior row of 4 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; 1 pair projecting spatulate setae on pronotum, 1 pair on anterior mesonotum; 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 3 pairs in two longitudinal rows.

Color orange brown.

Queen. Unknown.

Comments. This species is known from a single specimen from a pan trap, in mature wet forest at 500 m elevation on the Barva transect in Costa Rica. The larger eyes, longer legs, and fact that it was never sampled in hundreds of Winkler samples from the area suggest that it is a surface forager and perhaps arboreal.

Etymology. The name is in reference to the large eyes. It is a noun in apposition and thus invariant.

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.

FIGURE 15. Eurhopalothrix bolaui worker (Costa Rica, INBIOCRI 001222540). Scale bars: face view = 0.2 mm, lateral view = 0.5 mm.