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Costa Rica: Cordillera Volcanica Central, Braulio Carrillo National Park, Barva transect, 1100m.
This species is only known from one locality but it is relatively abundant at that locality. The Project ALAS survey at the 1070m site on the Barva transect yielded numerous collections in Malaise traps, pan traps on the ground, and Winkler samples of sifted leaf litter from the forest floor.
This minor worker of this species is superficially similar to erratilis. The propodeal spines of erratilis are triangular; those of this species are more spiniform. It is also quite similar to umphreyi, a species that occurs at higher elevations on the Barva transect.
Holotype major worker. Costa Rica, Heredia: 16km SSE La Virgen, 10.26667°N 84.08333°W, ±2000m, 1100m, 19 Mar 2001 (ALAS#11/WF/03/36) [INBC, unique specimen identifier INB0003214187].
Paratypes: major and minor workers. Same locality as holotype but 18 Feb 2001 (R. Vargas#01-RVC- 037), 17 Mar 2001 (R. Vargas#01-RVC-063), 16 Mar 2001 (M. Paniagua#11/RG/MPG/006), 20 Feb 2001 (ALAS#11/WF/01/13 and 11/WF/01/all), 19 Mar 2001 (ALAS#11/WF/03/24 and 11/WF/03/36) [BMNH, CAS, EAPZ, ECOSCE, FMNH, INBC, JTLC, LACM, MCZ, MHNG, MIZA, MZSP, MEL, UCD, UNAM, ICN, USNM].
Each caste separately with the morphometric profile of many species, but the combination of minor and major worker measurements and general habitus are similar to the allopatric Pheidole hedlundorumHNS (a montane species from Venezuela), and the sympatric P. umphreyi and P. erratilisHNS. Minor worker: not readily distinguishable from similar species; the propodeal spines are spiniform versus somewhat more triangular in erratilisHNS. Major worker: face with faint foveolate sculpture covering entire vertex lobes versus smooth and shining ( hedlundorumHNS, umphreyi); head with convex sides but not diverging, versus relatively more cordate ( hedlundorumHNS, umphreyi); hypostomal margin curved and inner hypostomal teeth stout, versus hypostomal margin relatively flat and inner hypostomal teeth reduced to inconspicuous denticles ( hedlundorumHNS, umphreyi).
Description of minor worker
Measurements (paratype): HL 0.66, HW 0.63, HLA 0.20, SL 0.67, EL 0.15, ML 0.83, PSL 0.06, PMG 0.01, SPL 0.03, PTW 0.13, PPW 0.19, CI 96, SI 106, PSLI 9, PMGI 1, SPLI 5, PPI 149.
Measurements (n=6): HL 0.60-0.66, HW 0.58-0.63, SL 0.64-0.67, CI 93-97, SI 106-114.
Mandible striate at base, grading to smooth and shiny on rest of dorsal surface; clypeus and face smooth and shiny; posterior margin of vertex flattened; occipital carina narrow, visible in full face view; scape rugulose, with abundant erect setae longer than maximum width of scape; promesonotal groove indistinct; propodeal spines present; pronotal humerus developed as an angular boss, with faint foveolate sculpture around boss, rest of pronotum smooth and shining; katepisternum and side of propodeum irregularly rugulose foveate; dorsal face of propodeum faintly foveolate; abundant setae on promesonotal dorsum; dorsal (outer) margin of hind tibia with erect setae subequal in length to maximum width of tibia; first gastral tergum smooth and shining; gastral dorsum with abundant erect setae; color dark red brown.
Description of major worker
Measurements (holotype): HL 1.20, HW 1.18, HLA 0.26, SL 0.68, EL 0.20, ML 1.01, PSL 0.11, PMG 0.00, SPL 0.05, PTW 0.19, PPW 0.30, IHT 0.25, OHT 0.39, CI 99, SI 57, PSLI 9, PMGI 0, SPLI 4, PPI 159, HTI 64.
FIGURE 15. Pheidole mesomontanaHNS. Major worker: A, face view; B, lateral view; C, dorsal view; D, hypostomal margin. Minor worker: E, face view; F, lateral view; G, dorsal view; H, hind tibia. A-D, Holotype major worker; E-H, Paratype minor worker. Scale bar 0.5mm for E, 1mm for others.
Measurements (n=3): HL 1.13-1.20, HW 1.12-1.18, SL 0.63-0.68, CI 99-101, SI 56-59.
Mandible striate at base, grading to smooth and shiny on rest of dorsal surface; clypeus smooth and shallowly concave, with shallow anterior notch; face with median groove, widely-spaced longitudinal rugae between frontal carinae and compound eye, obliquely radiating rugae between frontal carinae, grading to faint foveolate sculpture on vertex lobes; head with abundant suberect setae projecting from sides of head in face view; scape foveolate rugulose, not shining, slightly curved and flattened at base (but width at base still less than maximum width of scape at apex), with abundant erect setae longer than maximum width of scape; hypostomal margin strongly concave medially; median tooth broad, blunt; inner hypostomal teeth stout, slightly closer to outer hypostomal teeth than to midline; promesonotal groove absent; propodeal spines present; pronotal humerus developed as blunt tubercle; anterodorsal face of pronotum with widely-spaced, transverse rugulae; lateral face of pronotum smooth and shining; katepisternum, anepisternum, and side of propodeum coarsely and irregularly rugose; mesonotal dorsum broad, flat, with smooth spaces and irregular rugulae; dorsal face of propodeum with faint irregular rugulae; dorsal (outer) margin of hind tibia with abundant suberect setae subequal in length to maximum width of tibia; pilosity abundant on mesosomal dorsum; postpetiole in dorsal view weakly trapezoidal; first gastral tergite smooth and shining, with abundant erect setae; color dark red brown.
This species occurs in mature mid-elevation wet forest. It is known from only one locality but it is relatively abundant at that locality. The Project ALAS survey at the 1070m site on the Barva transect yielded numerous collections in Malaise traps, pan traps on the ground, and Winkler samples of sifted leaf litter from the forest floor.
The name is in reference to the narrow mid-elevation range of the species.
Found most commonly in these habitats: 37 times found in montane wet forest, 22 times found in cloud forest, primary, along steep ridge near peak, 12 times found in cloud forest, primary, near ridgetop.
Found most commonly in these microhabitats: 27 times Hojarasca, 21 times at bait, 13 times ex sifted leaf litter, 3 times Sobre Vegetacion, 1 times en el sendero, 1 times bajo de M/17, 1 times bajo de M/09, 1 times bajo de M/08, 1 times suelo suspendido, 1 times leaf litter, 1 times en vegetacion, ...
Collected most commonly using these methods: 27 times Mini Winkler, 21 times baiting, 12 times miniWinkler, 1 times maxiWinkler, 3 times flight intercept trap, 3 times Sweeping, 2 times Search, 1 times Berlese, 1 times Malaise.
Elevations: collected from 980 - 1130 meters, 1089 meters average
Type specimens: Holotype Pheidole mesomontana: inb0003214187; Paratype: fmnhins0000050036; Paratype Pheidole mesomontana: casent0609002, casent0609003, casent0609004, casent0609005, casent0609006, casent0609007, casent0609008, casent0609009, casent0609010, casent0609011, casent0609012, casent0609013, casent0609014, casent0609015, casent0609016, inb0003212167, inb0003212174, inb0003213478, inb0003213490, inb0003214188, inb0003224622, inb0003622618, inb0003622697