Pheidole sikorae Forel, 1891

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

publication ID

https://dx.doi.org/10.3897/zookeys.949.51269

publication LSID

lsid:zoobank.org:pub:93BFA448-BB73-43CD-BC4E-A86090DA63D5

persistent identifier

https://treatment.plazi.org/id/554932BE-F634-5443-A6E9-4C2C115F813E

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scientific name

Pheidole sikorae Forel, 1891
status

 

Pheidole sikorae Forel, 1891 Figs 53A-F View Figure 53 , 64K View Figure 64 , 67C View Figure 67

Type material.

Pheidole sikorae Forel, 1891: 223 (s.w.). Lectotype [designated here]: major worker (top specimen, CASENT0101692): Madagascar, Antananarivo, Andrangoloaka, coll. Sikora (MHNG) [examined]. Paralectotypes: 1 major worker (CASENT0876548, bottom specimen, the same pin as lectotype) (MHNG) [examined], 3 minor workers (CASENT0101668) (MHNG) [examined].

Other material.

Madagascar. - Fianarantsoa: • 1w., 1s.; 2 km W Andrambovato, along river Tatamaly; -21.51167, 47.41; alt. 1075 m; 3 Jun 2005; B. L. Fisher et al. leg.; montane rainforest, ex rotten pocket above ground; BLF12209 (CASC). • 6w., 3s.; Parc National de Ranomafana, Vatoharanana River, 4.1 km 231°SW Ranomafana; -21.29, 47.43333; alt. 1100 m; 27 Mar 2003; B. L. Fisher et al. leg.; montane rainforest, ex rotten log; BLF08414 (CASC).- Toamasina: • 1w., 1s.; Ile Sainte Marie, Forêt Ambohidena, 22.8 km 44° Ambodifotatra; -16.82433, 49.96417; alt. 20 m; 22 Nov 2005; B. L. Fisher et al. leg.; littoral rainforest, ex dead twig above ground; BLF12907 (CASC).- Toliara: • 1w., 1s.; Réserve Spéciale Kalambatritra, Ambinanitelo; -23.4502, 46.45658; alt. 1325 m; 11 Feb 2009; B. L. Fisher et al. leg.; montane rainforest, ex rotten log; BLF21764 (CASC). • 2w., 1s.; ibid.; BLF21779 (CASC). • 1w., 1m.; ibid.; BLF21794 (CASC). • 1w., 1s.; ibid.; BLF21805 (CASC). • 1w.; ibid.; BLF21826 (CASC). •1 w., 1m.; ibid.; BLF21829 (CASC). • 1w., 1s.; ibid.; BLF21843 (CASC). • 1w., 1s.; ibid.; BLF21849 (CASC). • 1w.; Réserve Spéciale Kalambatritra, Ampanihy; -23.4635, 46.4631; alt. 1270 m; 9 Feb 2009; B. L. Fisher et al. leg.; montane rainforest; BLF21567 (CASC). • 1w., 1s.; ibid.; BLF21609 (CASC). • 1w., 1s.; ibid.; under moss on rotten log; BLF21647 (CASC). • 1w., 1s.; Réserve Spéciale Kalambatritra, Ampanihy; -23.463, 46.47057; alt. 1269 m; 10 Feb 2009; B. L. Fisher et al. leg.; montane rainforest, ex rotten log; BLF21655 (CASC). • 1w., 1s.; ibid.; BLF21656 (CASC). • 2w., 1s., 1q.; ibid.; BLF21712 (CASC). • 1w., 1s.; ibid.; BLF21716 (CASC). • 1w., 1s.; Réserve Spéciale Kalambatritra, Ampanihy; -23.4635, 46.4631; alt. 1270 m; 10 Feb 2009; B. L. Fisher et al. leg.; montane rainforest, ex rotten log; BLF21745 (CASC). • 1w.; Réserve Spéciale Kalambatritra, Befarara; -23.4178, 46.4478; alt. 1390 m; 7 Feb 2009; B. L. Fisher et al. leg.; montane rainforest; BLF21329 (CASC). • 2w., 1s., 1m.; ibid.; ex rotten log; BLF21358 (CASC). • 1w., 1s.; ibid.; BLF21360 (CASC). • 1m.; ibid.; BLF21361 (CASC). • 1w., 1s.; ibid.; BLF21362 (CASC). • 2w., 1s., 1q.; ibid.; BLF21369 (CASC). • 1w., 1s.; ibid.; BLF21392 (CASC). • 1w., 1s.; ibid.; BLF21400 (CASC). • 1w., 1s.; Réserve Spéciale Kalambatritra, Betanana; -23.4144, 46.459; alt. 1360 m; 8 Feb 2009; B. L. Fisher et al. leg.; montane rainforest, ex rotten log; BLF21426 (CASC). • 1w., 1s.; ibid.; BLF21437 (CASC). • 1w., 1s.; ibid; under moss on rotten log; BLF21450 (CASC). • 1m.; ibid; ex rotten log; BLF21482 (CASC).

Diagnosis.

Moderately large species. Major workers. Head in full-face view sub-oval, widening posteriorly, with anterior and posterior sides convex, in lateral view sub-oval; ventral and dorsal faces convex; impressed and smooth concavity placed lateral to antennal socket and tentorial pit present; sides of the head with dense, long, suberect to erect pilosity; anterior and medial parts of frons with sparse, thick, longitudinal, and sometimes interrupted rugae and smooth to indistinctly rugulae interspaces; posterolateral sides with more irregular rugae and smooth to indistinctly rugulate interspaces, area posterolateral from eyes without smooth notches; scape, when laid back, exceeding the midlength of head by approximately one-third of its length; inner hypostomal teeth distinct, moderately high, closely spaced, triangular, with rounded apex and wide base; outer hypostomal teeth lobe-like, wider and higher than inner hypostomal teeth, apex directed outward; inner and outer hypostomal teeth closely spaced and connected by concavity; promesonotum predominantly smooth, with sparse, thin to thick, transverse rugae on pronotum and sometimes with fine, irregular rugulae on anepisternum and katepisternum; propodeum with fine, sparse, and indistinct rugulae; gaster smooth; body yellow to orange. Minor workers. Head sculpture variable, from smooth with foveolae restricted to anterior or medial frons to foveolate with smooth patches on vertex and area posterolateral from eyes; foveolae always sparse, frons sometimes with additional, sparse, and irregular rugae; scape, when laid back, surpassing the posterior head margin by one-fifth of its length; promesonotum moderately high and short; promesonotal groove present; propodeal spines very small and triangular; mesosoma smooth and shiny, only dorsum with few transverse, thick rugulae and propodeum with indistinct and sparse foveolae; body yellow to orange.

Description.

Major workers. Measurements (N = 10): HL: 0.94-1.18 (1.11); HW: 0.93-1.19 (1.14); SL: 0.65-0.7 (0.67); EL: 0.12-0.15 (0.14); WL: 0.9-1.07 (1.01); PSL: 0.13-0.19 (0.16); MTL: 0.59-0.69 (0.66); PNW: 0.39-0.5 (0.47); PTW: 0.13-0.15 (0.14); PPW: 0.23-0.3 (0.27); CI: 94.2-101.4 (97.3); SI: 55.6-69.7 (59.3); PSLI: 12.1-15.7 (14.5); PPI: 42.5-55.4 (50.1); PNI: 40.0-42.2 (41.5); MTI: 54.4-63.7 (57.7).

Head. In full-face view sub-oval, widening posteriorly, with anterior and posterior sides convex (Fig. 53B View Figure 53 ). In lateral view sub-oval; ventral and dorsal faces convex; inner hypostomal teeth invisible. Sides of the head with dense, long, suberect to erect pilosity; whole head with relatively dense, long, decumbent to erect pilosity. Anterior and medial parts of frons with sparse and thick, longitudinal, and sometimes interrupted rugae and smooth to indistinctly rugulate interspaces; posterolateral sides with more irregular rugae and smooth to indistinctly rugulate interspaces. Impressed and smooth concavity placed lateral to antennal socket and tentorial pit present. Occipital lobes with thick, sparse, irregular rugae, sometimes fading medially, interspaces smooth or with fine, indistinct rugulae. Gena with sparse, thick, and longitudinal rugae and smooth interspaces. Area posterolateral from eyes with weaker and sparser rugoreticulae. Centre of clypeus smooth and shiny, lateral sides with indistinct rugulae; median notch present, wide, and shallow; median longitudinal carina absent; lateral longitudinal carinae absent. Scape, when laid back, exceeding the midlength of head by approximately one-third of its length; pilosity decumbent to suberect (Fig. 53B, D View Figure 53 ). Inner hypostomal teeth distinct, moderately high, closely spaced, triangular, with rounded apex and wide base; outer hypostomal teeth lobe-like, wider and higher than inner hypostomal teeth, apex directed outward; inner and outer hypostomal teeth closely spaced and connected by concavity (Fig. 64K View Figure 64 ). Mesosoma. In lateral view, promesonotum short, angular, and moderately high, posterior mesonotum moderately steep, mesonotal process indistinct, tubercle-like; promesonotal groove absent; metanotal groove present; propodeal spines moderate, triangular, thin, with acute apex; humeral area laterally weakly produced (Fig. 53D View Figure 53 ). Surface shiny, promesonotum predominantly smooth, with sparse, thin to thick, transverse rugae on pronotum and sometimes with fine, irregular rugulae on anepisternum and katepisternum; propodeum with fine, sparse, and indistinct rugulae. Pilosity sparse, long, and erect (Fig. 53D, F View Figure 53 ). Petiole. Shiny with fine and sparse rugulae; peduncle; node smooth to indistinctly rugulose, low, triangular, with rounded apex, in rear view node dorsoventrally convex; pilosity moderately sparse and erect (Fig. 53D, F View Figure 53 ). Postpetiole. Shiny, with fine and sparse rugulae; in dorsal view postpetiole oval, lateral margins medially with two dentate projections; pilosity long, moderately sparse, and erect (Fig. 53D, F View Figure 53 ). Gaster. Shiny and smooth; pilosity sparse, long, and erect (Fig. 53D, F View Figure 53 ). Colour. Yellow to orange; gaster usually slightly darker (Fig. 53D, F View Figure 53 ).

Minor workers. Measurements (N = 10): HL: 0.55-0.61 (0.58); HW: 0.46-0.51 (0.49); SL: 0.58-0.63 (0.61); EL: 0.1-0.12 (0.11); WL: 0.67-0.76 (0.72); PSL: 0.06-0.08 (0.07); MTL: 0.45-0.53 (0.48); PNW: 0.3-0.35 (0.33); PTW: 0.07-0.09 (0.08); PPW: 0.13-0.16 (0.14); CI: 114.4-120.7 (118.4); SI: 121.9-127.5 (124.6); PSLI: 10.3-14.0 (11.8); PPI: 49.3-69.0 (60.6); PNI: 64.9-68.8 (67.5); MTI: 94.4-103.9 (98.9).

Head. Cephalic margin straight or indistinctly convex (Fig. 53A View Figure 53 ). Pilosity moderately dense, long, and erect. Head sculpture variable, from smooth with foveolae restricted to anterior or medial frons to foveolate with smooth patches on vertex and area posterolateral from eyes; foveolae always sparse, frons sometimes with additional, sparse, and irregular rugae; antennal sockets with few thick, curved outward rugae and smooth to foveolae 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, suberect to erect (Fig. 53A, C View Figure 53 ). Mesosoma. In lateral view, promesonotum moderately high, short, arched; promesonotal groove present, sometimes indistinct; metanotal groove present and distinct; propodeal spines very small and triangular, apex acute (Fig. 53C View Figure 53 ). Sculpture smooth and shiny, only dorsum with few transverse, thick rugulae and propodeum with indistinct and sparse foveolae. Pilosity sparse, moderately long, and erect (Fig. 53C, E View Figure 53 ). Petiole. Peduncle short and thin with ventral face slightly convex(Fig. 53C, E View Figure 53 ). Postpetiole. Short, low, and convex; with few short, erect setae (Fig. 53C, E View Figure 53 ). Gaster. With sparse, erect pilosity (Fig. 53C, E View Figure 53 ). Colour. Orange to yellow (Fig. 53C, E View Figure 53 ).

Biology.

The species was collected between 20-1580 m in elevation, in montane and littoral rainforest. Nests were located in rotten logs, dead twigs above ground, under moss, and rot pockets above ground.

Comments.

Major workers of Pheidole sikorae can be easily separated from all other Malagasy Pheidole based on strongly reduced sculpture of mesosoma and presence of impressed and smooth concavity placed lateral to antennal socket and tentorial pit. However, minor workers of P. sikorae have highly variable head sculpture. In most cases the head is predominantly smooth with sparse foveolae restricted to anterior and medial frons, but sometimes sparse foveolae extend to the whole frons and smooth patches are present only on vertex and area posterolateral from eyes. Minors of P. sikorae with strongly developed head sculpture are indistinguishable from minor workers of P. antranohofa sp. nov., a species known from Parc National de Marojejy in Antsiranana. Distribution ranges of these taxa do not overlap.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Hymenoptera

Family

Formicidae

Genus

Pheidole