Pheidole flavodepressa, 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 : 30-32

Pheidole flavodepressa sp. nov.

Figs 15 A–F, 27G, 28G

HOLOTYPE: 1s., Madagascar, Antsiranana, Makirovana forest , -14.104 50.03574, 225 m, 4-May-2011, rainforest, sifted litter (leaf mold, rotten wood), B. L. Fisher et al. leg. BLF27044, CASENT0243625 ( CASC) . PARATYPES: 1w., the same data as holotype, CASENT0230800 ( CASC) .

Other material. Madagascar. Antsiranana: 4w., 2s., Makirovana forest , -14.104 50.03574, 225 m, B. L. Fisher et al. leg. ( CASC) ; 1w., R.S. Manongarivo, 14.5 km 220° SW Antanambao , -13.99833 48.42833, 1175 m, B. L. Fisher et al. leg. ( CASC) .

Geographic range. Madagascar, Antsiranana, Makirovana forest and R.S. Manongarivo.

Diagnosis. Major workers. Head in full-face view sub-rectangular, elongated, not widening posteriorly, lateral margins relatively straight with very deep posteromedian concavity; side of head with moderately dense, long, subdecumbent to suberect pilosity; medial frons with dense and thick costulae; interspaces between costulae distinctly rugulate; frons laterally with thick and dense rugae; interspaces between rugae distinctly rugulate; occipital lobes with thick and dense rugae; interspaces between rugae distinctly rugulate; sculpture not weakening posteriorly; scape, when laid back, exceeding the midlength of head by two-fifths of its length; inner hypostomal tooth indistinct and bulge-like; outer hypostomal tooth lobe-like, high, and wide, with top arching posterolaterally; median tooth absent; promesonotum short, angular, and moderately low; posterior mesonotum smoothly declining towards propodeum; mesonotal process indistinct and tubercle-like; mesosoma punctate; promesonotum with additional thin, dense, and transverse rugae; katepisternum and lateral sides of propodeum with additional thick and dense rugulae; gaster shagreened; body orange. Minor workers. Occiput elongated forming moderately long and narrow neck; nuchal collar distinct; head sculpture smooth; scape, when laid back, exceeding the posterior head margin by three-fifths of its length; promesonotum low, very long, and arched; promesonotal groove present; metanotal groove distinct; propodeal spines long and thin; mesosoma smooth; body yellow.

Description. Major workers. Measurements (n=3): HL: 1.86–1.89 (1.88); HW: 1.56–1.66 (1.6); SL: 1.33–1.41 (1.37); EL: 0.2–0.23 (0.22); WL: 1.68–1.76 (1.71); PSL: 0.4–0.42 (0.41); MTL: 1.53–1.54 (1.54); PNW: 0.64–0.66 (0.65); PTW: 0.18–0.2 (0.19); PPW: 0.53–0.58 (0.56); CI: 113.7–119.3 (117.3); SI: 83.6–90.2 (85.8); PSLI: 21.0– 22.3 (21.9); PPI: 31.2–35.8 (33.8); PNI: 39.6–42.3 (40.7); MTI: 92.8–98.9 (95.9).

Head. In full-face view sub-rectangular, elongated, not widening posteriorly, lateral sides relatively straight with very deep posteromedian concavity ( Fig. 15B ). In lateral view sub-oval, not depressed posteriorly; ventral and dorsal margins convex; inner hypostomal tooth not visible. Side of head with moderately dense, long, subdecumbent to suberect pilosity; head dorsum with relatively dense, long, suberect to erect pilosity. Medial frons with dense and thick costulae; interspaces between costulae distinctly rugulate. Frons laterally with thick and dense rugae; interspaces between rugae distinctly rugulate. Occipital lobes with thick and dense rugae; interspaces between rugae distinctly rugulate; sculpture not weakening posteriorly. Gena with dense and moderately thick costulae; interspaces between costulae mostly smooth. Sides posterolateral from eyes with dense but very thin network of rugoreticulae; sculpture not weakening posteriorly. Center of clypeus shiny with few rugae, 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 two-fifths of its length; pilosity subdecumbent to erect ( Fig. 15B, D ). Inner hypostomal tooth indistinct, bulge-like; outer hypostomal tooth lobe-like, high, and wide, with top arching posterolaterally; median tooth absent ( Fig. 27G ). Mesosoma. In lateral view, promesonotum short, angular, and moderately low; posterior mesonotum smoothly declining towards propodeum; mesonotal process indistinct and tubercle-like; promesonotal groove absent; metanotal groove indistinct; propodeal spines long, with narrow base and acute top; humeral tubercle weakly produced ( Fig. 15D ). Surface punctate; promesonotum with additional thin, dense, and transverse rugae; katepisternum and lateral sides of propodeum with additional thick and dense rugulae. Pilosity dense, long, and erect ( Fig. 15D, F ). Petiole. In rear view node dorsoventrally slightly convex ( Fig. 15D, F ). Gaster. Dull and shagreened; pilosity moderately sparse, long, and erect ( Fig. 15D, F ). Color. Orange, antennae and legs yellow, gaster and mandibles brownish-orange ( Fig. 15D, F ).

Description. Minor workers. Measurements (n=5): HL: 0.84–0.91 (0.87); HW: 0.48–0.51 (0.49); SL: 1.26– 1.36 (1.31); EL: 0.14–0.16 (0.15); WL: 1.12–1.18 (1.14); PSL: 0.2–0.24 (0.22); MTL: 1.14–1.25 (1.19); PNW: 0.37–0.38 (0.38); PTW: 0.07–0.09 (0.08); PPW: 0.13–0.16 (0.15); CI: 173.5–185.3 (177.1); SI: 257.9–279.6 (266.9); PSLI: 22.8–27.6 (25.7); PPI: 49.0–62.0 (56.0); PNI: 74.4–79.6 (76.9); MTI: 236.1–256.3 (242.2).

Head. In full-face view oval, posterior region elongated forming moderately long and narrow neck; nuchal collar distinct ( Fig. 15A ). Pilosity relatively sparse, moderately long, subdecumbent to erect. Sculpture shiny and smooth. Clypeus with median longitudinal carina absent; two lateral longitudinal carinae absent. Scape, when laid back, exceeding the posterior head margin by three-fifths of its length; pilosity dense, subdecumbent to erect ( Fig. 15A, C ). Mesosoma. In lateral view, promesonotum low, very long, and arched; promesonotal groove present; metanotal groove distinct; propodeal spines long, thin, and triangular ( Fig. 15C ). Sculpture smooth. Pilosity very sparse, long, and erect ( Fig. 15C, E ). Gaster. With sparse and erect pilosity ( Fig. 15C, E ). Color. Yellow ( Fig. 15C, E ).

Biology. The species was collected between 225–1175 m elevation, in rainforest and montane rainforest. Nesting preferences are unknown. Workers were collected from sifted litter.

Comments. Pheidole flavodepressa is known from two localities in Antsiranana and is most similar to parapatric P. zirafy . Majors of P. flavodepressa can be separated based on orange body coloration, side of head with moderately dense, long and subdecumbent to suberect pilosity, and occipital lobes with thick and dense rugae with distinctly rugulate interspaces between rugae. Majors of P. zirafy have blackish brown body, moderately sparse, short and appressed to decumbent pilosity on side of head, and occipital lobes with rugae that are thin, weakening posteriorly, and archposterolaterally, with mostly smooth interspaces between rugae. Minors of P. flavodepressa have yellow body coloration, shorter and thicker neck, and smooth mesosoma. In contrast, P. zirafy has dark brown minors with longer and thinner neck and mostly sculptured mesosoma. Minor workers of P. flavodepressa may also be confused with those of P. antsahabe , P. similis , P. mantadioflava , and P. clara , but differ from them in distinctly longer and thinner neck.

Etymology. Latin for yellow and deep, in reference to the yellow body coloration and deep posteromedian concavity in major workers.

Figures

FIGURE 15. Pheidole flavodepressa, full-face view (A), profile (C), and dorsal view (E) of paratype minor worker (CASENT0230800) and full-face view (B), profile (D), and dorsal view (F) of holotype major worker (CASENT0243625).

FIGURE 27. Major worker, hypostomal tooth. Pheidole antsahabe (A). Pheidole atsirakambiaty (B). Pheidole bessonii (C). Pheidole clara (D). Pheidole decollata (E). Pheidole flammea (F). Pheidole flavodepressa (G). Pheidole grallatrix (H). Pheidole madecassa (I). Pheidole mantadioflava (J). Pheidole maro (K). Pheidole oswaldi (L). Pheidole ovalinoda (M). Pheidole similis (N). Pheidole tenebrovulgaris (O). Pheidole uranus (P). Pheidole voreios (Q). Pheidole zirafy (R).