Pheidole volontany, Salata & Fisher, 2020

Salata, Sebastian & Fisher, Brian L., 2020, Taxonomic revision of the Pheidole sikorae species group (Hymenoptera, Formicidae) from Madagascar, ZooKeys 949, pp. 1-185 : 1

Pheidole volontany sp. nov. Figs 61A-F , 64S , 67K

Type material.

Holotype. Madagascar. • 1 major worker; Toliara; Forêt Classée d’Analavelona, 33.2 km 344°NNW Mahaboboka; -22.64333, 44.17167; alt. 1300 m; 22 Feb 2003; Fisher et al. leg.; montane rainforest, ex rotten log; BLF07935; CASENT0491861, bottom specimen on the pin (CASC). Paratypes. • 9w., 3s.; same data as for holotype; CASENT0491860, CASENT0491863, CASENT0491862, CASENT0491864, CASENT0872247 (CASC, MHNG, PBZT).

Other material.

Madagascar. - Toliara: • 3w., 2s.; Forêt Classée d’Analavelona, 33.2 km 344°NNW Mahaboboka; -22.64333, 44.17167; alt. 1300 m; 22 Feb 2003; Fisher et al. leg.; montane rainforest, ex rotten log; BLF07925 (CASC). • 3w.; Forêt Classée d’Analavelona, 33.2 km 344°NNW Mahaboboka; -22.64333, 44.17167; alt. 1300 m; 22 Feb 2003; Fisher et al. leg.; montane rainforest, ex rotten log; BLF07926 (CASC). • 3w., 2s.; Forêt Classée d’Analavelona, 33.2 km 344°NNW Mahaboboka; -22.64333, 44.17167; alt. 1300 m; 22 Feb 2003; Fisher et al. leg.; montane rainforest, ex rotten log; BLF07927 (CASC). • 1w.; Forêt Classée d’Analavelona, 33.2 km 344°NNW Mahaboboka; -22.64333, 44.17167; alt. 1300 m; 22 Feb 2003; Fisher et al. leg.; montane rainforest, ex rotten log; BLF07928 (CASC). • 6w., 3s.; Forêt Classée d’Analavelona, 33.2 km 344°NNW Mahaboboka; -22.64333, 44.17167; alt. 1300 m; 22 Feb 2003; Fisher et al. leg.; montane rainforest, ex rotten log; BLF07931 (CASC). • 6w.; Forêt Classée d’Analavelona, 33.2 km 344°NNW Mahaboboka; -22.64333, 44.17167; alt. 1300 m; 22 Feb 2003; Fisher et al. leg.; montane rainforest, ex rotten log; BLF07939 (CASC). • 3w., 1s.; Forêt Classée d’Analavelona, 33.2 km 344°NNW Mahaboboka; -22.64333, 44.17167; alt. 1300 m; 22 Feb 2003; Fisher et al. leg.; montane rainforest, ex rotten log; BLF07952 (CASC).

Diagnosis.

Minute species. Major workers. HL <1.05 mm and WL <0.9 mm; head in full-face view sub-oval, slightly widening posteriorly, with anterior and posterior sides convex, in lateral view sub-oval; ventral and dorsal faces convex; body dark brown; sides of head with dense, very long, suberect to erect pilosity; entire head distinctly sculptured, medial part of frons with moderately dense, thick, longitudinal, and interrupted rugae, interspaces shiny and smooth; scape, when laid back, exceeding the midlength of head by one-fifth of its length; promesonotal dorsum with rugofoveolae and additional thick transverse to irregular rugae; lateral sides of pronotum, anepisternum, katepisternum, and propodeum with dense and moderately thick to thin rugoreticulae; inner hypostomal teeth distinct, large, closely spaced, triangular, with rounded apex directed slightly inward; outer hypostomal teeth lobe-like, wider than inner hypostomal teeth, and approximately the same height, apex directed outward; inner and outer hypostomal teeth closely spaced and connected by concavity; base of first gastral tergite smooth. Minor workers. HL <0.5 mm and WL <0.6 mm, scape, when laid back, surpassing the posterior head margin by one-fifth of its length; propodeal spines minute, triangular; head relatively oval, smooth, and shiny with a few short, longitudinal rugae on the anterolateral sides of head; body brown; mesosoma smooth, indistinct foveolae can occur on propodeal dorsum and lateral sides of pronotum.

Description.

Major workers. Measurements (N = 10): HL: 0.91-1.05 (0.98); HW: 0.97-1.06 (1.02); SL: 0.55-0.6 (0.57); EL: 0.12-0.15 (0.14); WL: 0.82-0.87 (0.85); PSL: 0.13-0.18 (0.15); MTL: 0.51-0.56 (0.53); PNW: 0.43-0.5 (0.46); PTW: 0.14-0.16 (0.15); PPW: 0.26-0.34 (0.3); CI: 93.0-101.0 (96.2); SI: 51.4-61.6 (56.3); PSLI: 13.3-17.7 (14.9); PPI: 44.0-58.0 (50.2); PNI: 44.0-58.0 (50.2); MTI: 49.2-53.6 (51.9).

Head. In full-face view sub-oval, slightly widening posteriorly, with anterior and posterior sides convex (Fig. 61B ). In lateral view sub-oval; ventral and dorsal faces convex; inner hypostomal teeth visible. Sides of the head with dense, very long, suberect to erect pilosity; whole head with dense, long, decumbent to erect pilosity. Medial part of frons with moderately dense, thick, longitudinal and interrupted rugae, interspaces shiny and smooth; anterolateral sides with longitudinal, thick, and dense rugae; interspaces shiny with relatively dense and distinct rugofoveolae; posterolateral sides with thick, dense, and irregular rugae with relatively dense and distinct rugofoveolae. Occipital lobes with sparse, thick, and irregular rugae; interspaces rugofoveolate. Gena with relatively dense, thick, longitudinal rugae and rugofoveolate interspaces. Area posterolateral from eyes shiny, with dense, thick rugofoveolae and smooth interspaces. Centre of clypeus smooth and shiny, lateral sides with indistinct rugulae; median notch present, moderately wide, and shallow; median longitudinal carina present; lateral longitudinal carinae absent. Scape, when laid back, exceeding the midlength of head by one-fifth of its length; pilosity subdecumbent to erect (Fig. 61B, D ). Inner hypostomal teeth distinct, large, closely spaced, triangular, with rounded apex directed slightly inward; outer hypostomal teeth lobe-like, wider than inner hypostomal teeth and approximately the same height, apex directed outward; inner and outer hypostomal teeth closely spaced and connected by concavity (Fig. 64S ). Mesosoma. In lateral view, promesonotum short, angular, and moderately low, posterior mesonotum moderately steep, mesonotal process indistinct, tubercle-like or absent; promesonotal groove absent; metanotal groove absent; propodeal spines moderately short, with wide base and acute apex; humeral area laterally weakly produced (Fig. 61D ). Surface shiny; promesonotal dorsum with rugofoveolae and additional thick transverse to irregular rugae; lateral sides of pronotum, anepisternum, katepisternum, and propodeum with dense and moderately thick to thin rugoreticulae. Pilosity sparse, long, and erect (Fig. 61D, F ). Petiole. Shiny with fine foveolae; node smooth to finely foveolate, low, triangular, with rounded and thin apex, in rear view node dorsoventrally straight to slightly convex; pilosity moderately sparse and erect (Fig. 61D, F ). Postpetiole. Shiny and foveolate; dorsum with reduced sculpture and smooth notch; in dorsal view oval, lateral margins medially with two dentate projections; pilosity long, moderately sparse, and erect (Fig. 61D, F ). Gaster. Shiny and smooth; pilosity dense, long, and erect (Fig. 61D, F ). Colour. Dark brown; legs and antennae yellow (Fig. 61D, F ).

Minor workers. Measurements (N = 10): HL: 0.48-0.51 (0.5); HW: 0.44-0.46 (0.45); SL: 0.47-0.51 (0.49); EL: 0.09-0.11 (0.1); WL: 0.57-0.62 (0.59); PSL: 0.06-0.08 (0.07); MTL: 0.37-0.39 (0.38); PNW: 0.27-0.31 (0.29); PTW: 0.06-0.08 (0.07); PPW: 0.11-0.13 (0.12); CI: 108.8-116.0 (112.0); SI: 105.4-111.4 (108.4); PSLI: 11.2-14.6 (13.0); PPI: 56.9-70.2 (62.7); PNI: 61.4-68.6 (65.3); MTI: 81.3-88.2 (84.3).

Head. Cephalic margin indistinctly concave or straight (Fig. 61A ). Pilosity relatively sparse, long, decumbent to suberect. Sculpture smooth and shiny with a few short, longitudinal rugae on the anterolateral sides of head; antennal sockets with few thick, curved outward rugae and smooth interspaces. Clypeus with median longitudinal carina absent; two lateral longitudinal carinae absent. Scape, when laid back, surpassing the posterior head margin by one-fifth of its length; pilosity dense, subdecumbent to erect (Fig. 61A, C ). Mesosoma. In lateral view, promesonotum moderately high and short, arched; promesonotal groove absent; metanotal groove distinct; propodeal spines minute, triangular (Fig. 61C ). Sculpture shiny and smooth; indistinct foveolae can occur on propodeal dorsum and lateral sides of pronotum. Pilosity very sparse, moderately long, and erect (Fig. 61C, E ). Postpetiole. Short, low, and relatively flat; with few short, erect setae (Fig. 61C, E ). Gaster. With sparse, erect pilosity (Fig. 61C, E ). Colour. Brown, legs and antenna yellow (Fig. 61C, E ).

Etymology.

Malagasy for brown in reference to body colouration.

Biology.

The species was collected at 1300 m in elevation, in montane rainforest. Nests were located in rotten logs.

Comments.

Pheidole volontany sp. nov. belongs to the group of species characterised by small body size (major workers: HL <1.05 mm, WL <0.9 mm and minor workers HL <0.5 mm, WL <0.6 mm), sub-oval, slightly widening posteriorly head with anterior and posterior sides convex in major workers, and minor workers with yellow to brown body colouration and foveolate head or head predominantly smooth and relatively oval. The group includes six species: P. havoana sp. nov., P. kely sp. nov., P. parvula sp. nov., P. parvulogibba sp. nov., P. volontany sp. nov., and P. midongy sp. nov. Because of dark body colouration P. volontany sp. nov., known from Forêt Classée d’Analavelona in Toliara, is most similar to P. midongy sp. nov., described form Parc National Befotaka-Midongy in Fianarantsoa. Major workers of P. volontany sp. nov. differ from P. midongy sp. nov. in frons with moderately dense, thick, longitudinal, and interrupted rugae with shiny and smooth interspaces, and sides of the head with dense, very long, suberect to erect pilosity; minor workers differ in predominantly smooth head and darker brown body colouration.

Figures

Figure 61. Pheidole volontany Forel, full-face view (A), profile (C), and dorsal view (E) of minor paratype worker (CASENT 0491862) and full-face view (B), profile (D), and dorsal view (F) of holotype major worker (CASENT 0491861).

Figure 64. Major worker, hypostomal teeth. Pheidole masoandro sp. nov. (A). Pheidole mavohavoana sp. nov. (B). Pheidole midongy sp. nov. (C). Pheidole mikros sp. nov. (D). Pheidole mivory sp. nov. (E). Pheidole nitidobruna sp. nov. (F). Pheidole parvula sp. nov. (G). Pheidole parvulogibba sp. nov. (H). Pheidole renirano sp. nov. (I). Pheidole sava sp. nov. (J). Pheidole sikorae Forel (K). Pheidole sofia sp. nov. (L). Pheidole sparsa sp. nov. (M). Pheidole tampony sp. nov. (N). Pheidole trichotos sp. nov. (O). Pheidole tsaravoniana sp. nov. (P). Pheidole vadum sp. nov. (Q). Pheidole veteratrix Forel (R). Pheidole volontany sp. nov. (S). Pheidole vony sp. nov. (T).

Figure 67. Distribution. Pheidole renirano sp. nov. (A). Pheidole sava sp. nov. (B). Pheidole sikorae Forel (C). Pheidole sofia sp. nov. (D). Pheidole sparsa sp. nov. (E). Pheidole tampony sp. nov. (F). Pheidole trichotos sp. nov. (G). Pheidole tsaravoniana sp. nov. (H). Pheidole vadum sp. nov. (I). Pheidole veteratrix Forel (J). Pheidole volontany sp. nov. (K). Pheidole vony sp. nov. (L).