Pheidole zirafy, 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 : 59-63

Pheidole zirafy sp. nov.

Figs 26 A–F, 27R, 28R

HOLOTYPE: 1s., Madagascar, Antsiranana, Sava Region: Parc National de Marojejy, Manantenina River , 28.0 km 24.8° NE Andapa, -14.43461 49.76074, 780 m, 13-Feb-2018, rainforest, ex rotten log, B. L. Fisher et al. leg. BLF41182, CASENT0923249 ( CASC) . PARATYPES: 3w., 1m.: the same data as holotype, CASENT0807266, CASENT0807267, CASENT0807268 ( CASC, MHNG, PBZT) .

Other material. Madagascar. Antsiranana: 4w., Parc National de Marojejy, Manantenina River , 28.0 km 38° NE Andapa, 8.2 km 333° NNW Manantenina, -14.43667 49.775, 450 m, B. L. Fisher et al. leg. ( CASC) ; 6w., SAVA Region, District of Sambava, Marojejy National Park , 5 km W of Manantenina village, 1st Camp site (Mantella), -14.43817 49.774, 487 m, M. Rin’Ha leg. ( CASC) ; 1w., Sava Region: Parc National de Marojejy, near Manantenina River , -14.43677 49.77541, 475 m, B. L. Fisher et al. leg. ( CASC) .

Geographic range. Madagascar, Antsiranana, Sava Region.

Diagnosis. Major workers. Head in full-face view sub-rectangular, widening posteriorly, with lateral margins relatively straight and very deep posteromedian concavity; side of head with moderately sparse, short, appressed to decumbent pilosity; anteromedial part of frons with moderately thick and dense costulae; interspaces between costulae smooth; posteromedial frons with thinner rugocostulae that arch posterolaterally; interspaces between rugocostulae rugulate; frons laterally with denser and thicker rugae; interspaces between rugae with dense and thin rugulae; occipital lobes with thin rugocostulae that weaken posteriorly and arch posterolaterally, interspaces between rugocostulae mostly smooth; scape, when laid back, exceeding the midlength of head by three-fifths of its length; inner hypostomal tooth distinct, low, wide, closely spaced and bulge-like; outer hypostomal tooth lobe-like and higher than inner tooth, with top directed posteriorly; inner and outer hypostomal tooth closely spaced and not connected by concavity; promesonotum short, angular and low; posterior mesonotum smoothly declining towards propodeum; mesonotal process distinct and tubercle-like; mesosoma with dense and thin rugopuncta; pronotum with additional thin, moderately dense, and transverse rugae; anepisternum, katepisternum, and lateral sides of propodeum with rugae that are more vertical; gaster shagreened; body brownish black. Minor workers. Occiput elongated, terminated by distinct nuchal collar; head sculpture mostly smooth with few rugae on gena and transverse rugae on neck; scape, when laid back, exceeding the posterior head margin by half of its length; promesonotum very low, long, and slightly arched; promesonotal groove present; metanotal groove indistinct; propodeal spines long and thin; promesonotal and propodeal dorsum mostly smooth with sparse and transverse rugae, and lateral sides of propodeum, anepisternum, and katepisternum with dense and thin rugoreticulae; body dark brown.

Description. Major workers. Measurements (n=1): HL: 2.44; HW: 2.21; SL: 1.8; EL: 0.246; WL: 2.19; PSL: 0.57; MTL: 2.22; PNW: 0.8; PTW: 0.28; PPW: 0.69; CI: 110.5; SI: 81.4; PSLI: 23.4; PPI: 40.6; PNI: 36.0; MTI: 100.7.

Head. In full-face view sub-rectangular, side relatively straight, posteromedian concavity very deep ( Fig. 26B ). In lateral view sub-oval, not depressed posteriorly, ventral and dorsal margin convex; inner hypostomal tooth visible. Side of head with moderately sparse, short, appressed to decumbent pilosity; head dorsum with relatively dense, long, decumbent to erect pilosity. Anteromedial part of frons with moderately thick and dense costulae; interspaces between costulae smooth; posteromedial frons with rugocostulae that are thinner and arch posterolaterally; interspaces between rugocostulae rugulate; frons laterally with dense and thick rugae; interspaces between rugae rugulate. Occipital lobes with thin rugocostulae that weaken posteriorly and arch posterolaterally; interspaces between rugocostulae mostly smooth. Gena with dense and thick costulae; interspaces between costulae distinctly rugulate. Sides posterolateral from eyes with dense and thin rugae; interspaces between rugae distinctly rugulate. Center of clypeus shiny and indistinctly rugulate, lateral sides with weakly developed rugulae; median notch present, moderately wide and shallow; median longitudinal carina present; lateral longitudinal carinae present. Scape, when laid back, exceeding midlength of head by three-fifths its length; pilosity subdecumbent to erect ( Fig. 26B, D ). Inner hypostomal tooth distinct, low, wide, closely spaced and bulge-like; outer hypostomal tooth lobe-like, higher than inner tooth, top directed posteriorly; inner and outer hypostomal tooth closely spaced and not connected by concavity ( Fig. 27R ). Mesosoma. In lateral view, promesonotum short, angular and low; posterior mesonotum smoothly declining towards propodeum; mesonotal process distinct and tubercle-like; promesonotal groove absent; metanotal groove present; propodeal spines long, narrow and with acute top; humeral tubercle weakly produced ( Fig. 26D ). Surface shiny and with dense and thin rugopuncta; pronotum with additional thin, moderately dense, and transverse rugae; anepisternum, katepisternum, and lateral sides of propodeum with rugae that are more vertical. Pilosity moderately dense, short, and erect ( Fig. 26D, F ). Petiole. Shagreened ( Fig. 26D, F ). Postpetiole. Shagreened; dorsum with slightly sparser sculpture ( Fig. 26D, F ). Gaster. Dull and shagreened; pilosity moderately sparse, long, and erect ( Fig. 26D, F ). Color. Brownish black, antennae and legs dark brown, mandibles reddish brown ( Fig. 26D, F ).

Description. Minor workers. Measurements (n=10): HL: 1.17–1.44 (1.29); HW: 0.6–0.75 (0.66); SL: 1.83– 2.13 (1.95); EL: 0.14–0.22 (0.18); WL: 1.53–1.91 (1.69); PSL: 0.34–0.45 (0.38); MTL: 1.85–2.37 (2.03); PNW: 0.45–0.58 (0.52); PTW: 0.11–0.16 (0.13); PPW: 0.19–0.24 (0.22); CI: 188.4–200.0 (193.8); SI: 282.2–302.6 (293.2); PSLI: 26.7–31.3 (29.2); PPI: 49.6–70.6 (58.1); PNI: 74.5–79.5 (77.5); MTI: 290.9–314.9 (305.2).

Head. In full-face view oval, posterior region elongated into long and narrow neck terminated by distinct nuchal collar ( Fig. 26A ). Pilosity relatively sparse, moderately long, and subdecumbent to erect. Sculpture shiny and mostly smooth with few rugae on gena and transverse rugae on neck; antennal sockets with few weakly developed rugulae that curve posterolaterally; interspaces between rugulae smooth. Clypeus with median longitudinal carina absent; two lateral longitudinal carinae absent. Scape, when laid back, exceeding the posterior head margin, neck not included, by half of its length; pilosity dense and subdecumbent to erect ( Fig. 26A, C ). Mesosoma. In lateral view, promesonotum very low, long, and slightly arched; promesonotal groove present; metanotal groove in distinct; propodeal spines long, thin, and triangular ( Fig. 26C ). Promesonotal and propodeal dorsum mostly smooth with sparse and transverse rugae; lateral sides of propodeum, anepisternum, and katepisternum, with dense and thin rugoreticulae. Pilosity very sparse, short, and erect ( Fig. 26C, E ). Petiole. Peduncle with ventral face straight ( Fig. 26C, E ). Gaster. With sparse and erect pilosity ( Fig. 26C, E ). Color. Dark brown, legs and antennae brighter ( Fig. 26C, E ).

Biology. The species was collected between 450–780 m elevation, in low elevation rainforest and rainforest. Nests were located in rotten logs, and workers were collected from sifted litter and on the ground.

Comments. Majors of P. zirafy are most similar to parapatric P. flavodepressa and differ in blackish brown body, presence of moderately sparse, short, and appressed to decumbent pilosity on side of head, occipital lobes with thin rugae that weaken posteriorly and arch posterolaterally, and mostly smooth interspaces between rugae. In contrast, P. flavodepressa has orange body coloration, side of head with moderately dense, long, subdecumbent to suberect pilosity, and occipital lobes with thick and dense rugae and distinctly rugulate interspaces between rugae. Minors of P. zirafy are most similar to sympatric P. grallatrix and differ in presence of dense and thin rugoreticulae on lateral sides of propodeum, anepisternum, and katepisternum. Minors of P. grallatrix have entirely smooth mesosoma.

Etymology. Malagasy for giraffe, in reference to the very long neck of minor workers.

Figures

FIGURE 26. Pheidole zirafy, full-face view (A), profile (C), and dorsal view (E) of paratype minor worker (CASENT0807268) and full-face view (B), profile (D), and dorsal view (F) of holotype major worker (CASENT0923249).

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).