Pheidole ovalinoda, Salata & Fisher, 2020

Salata, Sebastian & Fisher, Brian L., 2020, The ant genus Pheidole Westwood, 1839 (Hymenoptera: Formicidae) in Madagascar-taxonomic revision of the bessonii species-group, Zootaxa 4843 (1), pp. 1-64 : 47-49

Pheidole ovalinoda sp. nov.

Figs 21 A–F, 27M, 28M

HOLOTYPE: 1s., Madagascar, Antsiranana, Sava Region: Parc National de Marojejy, Manantenina River , 27.9 km 24.3° NE Andapa, -14.43462 49.75853, 850 m, 9-Feb-2018, rainforest, ex tunelle on clay bark, B. L. Fisher et al. leg. BLF40902, CASENT0808080 ( CASC) . PARATYPES: 1w., the same data as holotype, CASENT0923277 ( CASC) .

Other material. Madagascar. Antsiranana: 3w., 2s., Sava Region: Parc National de Marojejy, Manantenina River , 27.9 km 24.3° NE Andapa, -14.43462 49.75853, 850 m, B. L. Fisher et al., ( CASC) .

Geographic range. Madagascar, Antsiranana, Parc National de Marojejy.

Diagnosis. Major workers. Head in full-face view sub-rectangular, not widening posteriorly, with lateral margins relatively straight; side of head with dense, short, decumbent to suberect pilosity; anteromedial frons with moderately dense and thick costulae; interspaces between costulae indistinctly rugulate; posteromedial frons rugulate; interspaces between rugulae more distinctly rugulate; frons laterally with thick and moderately dense rugae; interspaces between rugae indistinctly rugulate; occipital lobes with thick and moderately dense rugae; interspaces between rugae mostly smooth; scape, when laid back, exceeding the midlength of head by one-fifth of its length; inner hypostomal tooth distinct and bulge-like; outer hypostomal tooth absent to very indistinct; median tooth absent; promesonotum short, angular, and moderately low; posterior mesonotum moderately steep; mesonotal process distinct; mesosoma microreticulate, lateral sides of pronotum, propodeum, and katepisternum with additional thin rugae; pronotal dorsum with additional rugae; gaster shagreened; body brown. Minor workers. Occiput not elongated; nuchal collar indistinct; head sculpture smooth; scape, when laid back, exceeding the posterior head margin by two-fifths of its length; promesonotum moderately low, moderately long, and arched; promesonotal groove present; metanotal groove distinct; propodeal spines very small and thin; promesonotum smooth; anepisternum, katepisternum, and propodeum punctate; body yellowish brown; petiolar node high, triangular, and thick.

Description. Major workers. Measurements (n=4): HL: 1.35–1.5 (1.41); HW: 1.3–1.43 (1.36); SL: 0.92–0.98 (0.95); EL: 0.18–0.19 (0.18); WL: 1.25–1.35 (1.29); PSL: 0.2–0.23 (0.22); MTL: 0.95–1.02 (0.99); PNW: 0.53– 0.57 (0.56); PTW: 0.17–0.19 (0.18); PPW: 0.33–0.42 (0.38); CI: 101.9–105.3 (103.9); SI: 68.5–71.1 (70.2); PSLI: 14.8–16.6 (15.7); PPI: 43.3–50.5 (46.3); PNI: 39.9–41.7 (41.0); MTI: 71.4–74.3 (73.1).

Head. In full-face view sub-rectangular, not widening posteriorly, with lateral sides relatively straight ( Fig. 21B ). In lateral view sub-oval, not depressed posteriorly; ventral and dorsal margins convex; inner hypostomal tooth visible. Side of head with dense, short, decumbent to suberect pilosity; head dorsum with relatively dense, long, suberect to erect pilosity. Anteromedial frons with moderately dense and thick costulae; interspaces between costulae indistinctly rugulate; posteromedial frons rugulate; interspaces between rugulae more distinctly rugulate. Frons laterally with thick and moderately dense rugae; interspaces between rugae indistinctly rugulate. Occipital lobes with thick and moderately dense rugae; interspaces between rugae mostly smooth. Gena with dense and moderately thick costulae; interspaces between costulae mostly punctate. Sides posterolateral from eyes with thick rugulae; interspaces between rugulae distinctly rugulate. Center of clypeus shiny with weakly developed puncta, lateral sides with distinct rugulae; median notch present, moderately wide and shallow; median longitudinal carina present; lateral longitudinal carinae present. Scape, when laid back, exceeding the midlength of head by one-fifth of its length; pilosity subdecumbent to erect ( Fig. 21B, D ). Inner hypostomal tooth distinct, bulge-like; outer hypostomal tooth absent to very indistinct; median tooth absent ( Fig. 21M ). Mesosoma. In lateral view, promesonotum short, angular, and moderately low; posterior mesonotum moderately steep; mesonotal process distinct and tubercle-like; promesonotal groove absent; metanotal groove indistinct; propodeal spines moderately long with moderately wide base and acute top; humeral tubercle weakly produced ( Fig. 21D ). Surface microreticulate; lateral sides of pronotum, propodeum, and katepisternum with additional thin rugae; pronotal dorsum with additional rugae. Pilosity moderately dense, long, and erect ( Fig. 21D, F ). Gaster. Shiny and shagreened; pilosity moderately sparse, long, and erect ( Fig. 21D, F ). Color. Brown, legs yellowish ( Fig. 21D, F ).

Description. Minor workers. Measurements (n=4): HL: 0.6–0.64 (0.62); HW: 0.46–0.49 (0.47); SL: 0.77–0.8 (0.79); EL: 0.11–0.13 (0.13); WL: 0.81–0.87 (0.84); PSL: 0.09–0.1 (0.09); MTL: 0.64–0.67 (0.65); PNW: 0.3–0.35 (0.33); PTW: 0.08–0.11 (0.09); PPW: 0.12–0.14 (0.13); CI: 127.6–134.7 (130.5); SI: 162.9–170.7 (166.1); PSLI: 14.1–15.7 (14.8); PPI: 59.4–79.9 (69.6); PNI: 64.4–73.8 (70.0); MTI: 134.5–138.6 (137.3).

Head. In full-face view oval, posterior region not elongated; nuchal collar weakly developed ( Fig. 21A ). Pilosity relatively sparse, moderately short, subdecumbent to erect. Sculpture mostly smooth; anterolateral frons punctate. Clypeus with median longitudinal carina absent; two lateral longitudinal carinae absent. Scape, when laid back, exceeding the posterior head margin by two-fifths of its length; pilosity dense, subdecumbent to erect ( Fig. 21A, C ). Mesosoma. In lateral view, promesonotum moderately low, moderately long, and arched; promesonotal groove present; metanotal groove distinct; propodeal spines very small, thin, and triangular ( Fig. 21C ). Promesonotum smooth; anepisternum, katepisternum, and propodeum punctate. Pilosity sparse, moderately long, and erect ( Fig. 21C, E ). Gaster. With sparse and erect pilosity ( Fig. 21C, E ). Color. Yellowish brown, gaster and head darker than mesosoma ( Fig. 21C, E ).

Biology. The species was collected at 850 m elevation, in rainforest. Nests were located in the soil and on clay banks.

Comments. Pheidole ovalinoda is known only from Parc National de Marojejy in Antsiranana. Its major workers can be confused with parapatric P. flammea , recorded only from Galoko Mountain. Majors of P. ovalinoda differ from P. flammea in the presence of dense, short and decumbent to suberect setae on the sides of the head, strongly reduced outer hypostomal tooth, and more distinctly sculptured interspaces between rugae on head. Majors of P. flammea have moderately dense, long and suberect to erect pilosity on the side of the head, large outer hypostomal tooth, and mostly smooth interspaces between rugae on head. Minors of P. ovalinoda are easy to separate from other Pheidole known from the island based on the combination of the following characters: petiolar node high, triangular, and thick; postpetiole short and moderately high; yellowish brown body coloration; neck absent, and nuchal collar indistinct; head and promesonotum mostly smooth; promesonotal and metanotal grooves distinct.

Etymology. Latin for oval and node, in reference to the high and spherical postpetiole of minor workers.

Figures

FIGURE21.Pheidoleovalinoda,full-faceview(A),profile(C),anddorsalview(E)ofparatypeminorworker(CASENT0923277) and full-face view (B), profile (D), and dorsal view (F) of holotype major worker (CASENT0808080).