A revision of Pheidole Westwood (Hymenoptera: Formicidae) in the islands of the Southwest Indian Ocean and designation of a neotype for the invasive Pheidole megacephala Author FISCHER, G. Author FISHER, B. L. text Zootaxa 2013 2013-07-05 3683 4 301 356 http://dx.doi.org/10.11646/zootaxa.3683.4.1 journal article 20094 10.11646/zootaxa.3683.4.1 4f6d65aa-8c5b-48ca-9d27-ee17d022a1b9 1175-5326 5641557 2A3C7450-C8D8-479C-A295-C2BB49A151EF Pheidole fervens Smith, F. ( Figs. 17A–F ) Pheidole fervens Smith, F. 1858: 176 . Lectotype ( 1 major worker , CASENT0901520 ) [designated here]: SINGAPORE ( BMNH ) [examined]; paralectotype ( 1 minor worker , CASENT0901519 ): same data as lectotype ( BMNH ) [examined] . Solenopsis pungens Smith, 1861: 48 . Lectotype (major worker), designated by Eguchi (2004) : INDONESIA ( Sulawesi ) [not examined]. Combination in Pheidologeton : Donisthorpe, 1932: 469 ; in Pheidole : Bolton, 1995: 328 . Junior synonym of Pheidole fervens : Eguchi, 2004: 198 . Pheidole javana Mayr, 1867: 98 . Lectotype (major worker), designated by Eguchi (2004) : INDONESIA ( Java ) [not examined]. Junior synonym of Pheidole fervens : Wilson & Taylor, 1967: 45 . Pheidole cavannae Emery, 1887: 464 . Syntype (s) (major worker(s)): NEW CALEDONIA [not examined]. Subspecies of Pheidole oceanica : Emery, 1914: 401 . Junior synonym of Pheidole fervens : Wilson & Taylor, 1967: 45 . Pheidole javana var. dharmsalana Forel, 1902: 184 , 198. Lectotype (major worker), designated by Eguchi (2004) : INDIA [not examined]. [Also described as new by Forel, 1902: 546 ]. Subspecies of Pheidole fervens : Bolton, 1995: 320 . Junior synonym of Pheidole fervens : Eguchi, 2004: 198 . Pheidole amia Forel, 1912: 60 . Lectotype (major worker), designated by Eguchi (2004) : TAIWAN [not examined]. Junior synonym of Pheidole fervens : Eguchi, 2004: 197 . Pheidole javana var. dolenda Forel, 1912: 60 . Lectotype (major worker), designated by Eguchi (2004) : TAIWAN [not examined]. Subspecies of Pheidole fervens : Bolton, 1995: 320 . Junior synonym of Pheidole fervens : Eguchi, 2004: 198 . Pheidole oceanica subsp. nigriscapa Santschi, 1928: 48 . Syntypes (1 major worker, 7 minor workers): SAMOA [not examined]. Junior synonym of Pheidole fervens : Wilson & Taylor, 1967: 45 . Pheidole oceanica subsp. nigriscapa var. tahitiana Cheesman & Crawley, 1928: 516 . TAHITI [not examined]. Unavailable name; material referred to Pheidole fervens by Wilson & Taylor, 1967: 45 . Pheidole javana var. desucta Wheeler, 1929: 2 . Lectotype (major worker), designated by Eguchi (2001) : CHINA [not examined]. Subspecies of Pheidole fervens : Bolton, 1995: 320 . Junior synonym of Pheidole fervens : Eguchi, 2001: 53 . Pheidole javana var. soror Santschi, 1937b: 369 . Lectotype (major worker), designated by Eguchi (2004) : TAIWAN [not examined]. Subspecies of Pheidole fervens : Bolton, 1995: 330 . Junior synonym of Pheidole fervens : Eguchi, 2004: 198 . Pheidole nodus st. azumai Santschi, 1941: 274 . Lectotype (major worker), designated by Eguchi (2004) : JAPAN [not examined]. Junior synonym of Pheidole fervens : Eguchi, 2004: 198 . FIGURE 17 Pheidole fervens Mayr , full-face view (A), profile (B), and dorsal view (C) of minor worker (CASENT006581) and full-face view (D), profile (E), and dorsal view (F) of major worker (CASENT0060250). Diagnosis: Large species (WL major 1.06–1.17, WL minor 0.82–0.91), minor workers with relatively long scapes and legs (SI 133–154, FI 142–158) and major workers with long scapes and relatively long legs (SI 61–71, FI 84–91), both with promesonotal processes well developed and postpetiolar ventral process inconspicuous or very shallow. Major with frontal carinae reaching at least 4/5 of the distance to the posterior head margin, face longitudinally rugose, scrobe area and interspaces at sides of head punctate to weakly punctate, head in full-face view with coarse suberect hairs, eyes moderately large (EI 13–15), in profile metanotal groove vestigial to absent, propodeum sloped down toward spines, postpetiole in dorsal view trapezoidal and almost twice as wide as petiole (PpWI 172-195). Minor head oval and rounded posteriorly, occipital carina visible in full-face view but not well developed, face mostly smooth, often with fine, long rugulae at the sides, sometimes together with superficial punctures. Eyes moderately large (EI 21–25), dorsal promesonotum smooth, promesonotal process developed, subangulate in profile, metanotal groove well developed, impressed, propodeum relatively high and sloped toward spines. Description of major workers: Measurements (n=5): HW 1.13–1.31 (1.25), HL 1.13–1.38 (1.28), SL 0.80– 0.86 (0.83), MDL 0.61–0.71 (0.67), EL 0.16–0.17 (0.17), WL 1.06–1.17 (1.14), PNH 0.41–0.49 (0.45), PNW 0.54–0.59 (0.56), MNH 0.72–0.79 (0.77), PDH 0.34–0.39 (0.36), PTL 0.36–0.40 (0.38), PPL 0.23–0.26 (0.24), PTH 0.22–0.26 (0.24), PPH 0.16–0.22 (0.20), PTW 0.17–0.20 (0.19), PPW 0.31–0.39 (0.34), PSL 0.13–0.17 (0.15), MFL 1.03–1.13 (1.08), MTL 0.77–0.84 (0.82), CI 95–100 (98), SI 61–71 (67), MDI 50–56 (53), EI 13–15 (13), FI 84–91 (87), PSLI 10–14 (12), LPpI 110–144 (120), DPpI 133–150 (143), PpWI 172–195 (183), PpLI 60– 68 (64), PpHI 70–95 (86). Head almost as wide as long (CI 95–100), sides convex in full-face view. Mandibles smooth, moderately long (MDI 50–56), clypeus smooth, median carina absent and two weak lateral carinae present. Frontal carinae well developed and reaching at least 4/5 of the distance to posterior head margin, antennal scrobe present and punctate. Face longitudinally rugose, interspaces on frons superficially punctate, sides of head and posterolateral lobes with additional cross-meshes between rugae or weakly reticulate, interspaces punctate or weakly punctate. Scapes long (SI 61–71) with decumbent to subdecumbent pilosity and few longer, erect hairs on outer edge. Eyes well developed, moderately large (EI 13–15). Submedian hypostomal teeth and median process small to inconspicuous. Promesonotum high-domed, convex, posteriorly subangulate, in profile with prominent angulate promesonotal process and transverse groove. Dorsum of pronotum mostly smooth with some weak to superficial transverse rugulae, lateropronotum smooth except for weak to superficial curved rugulae, rest of mesosoma punctate, dorsally more weakly so, metanotal groove in profile not impressed or very shallow, with cross-ribs often reduced, dorsum of propodeum in profile usually weakly sloped toward spines and about as long as posterior declivity. Propodeal spines short-spiniform, acute, sometimes very weakly curved posteriorly, slightly shorter than distance between their bases (PSLI 10–14). Metatibia moderately long (FI 84–91), pilosity mostly subdecumbent, along outer edge also with longer suberect hairs. Postpetiole on average 1.4 times wider than long (DPpI 133–150) and 1.8 times wider than petiole (PpWI 172–195), postpetiole shape in dorsal view trapezoidal to hexagonal, sides angulate, ventral process absent or inconspicuous. Dorsum of petiole weakly to superficially punctate, of postpetiole smooth, remainder of both waist segments punctate. Gaster smooth. Standing hairs relatively coarse and abundant, of medium length to moderately long, yellowish, with shorter subdecumbent pilosity between. Color usually brown to darker brown, with darker gaster. Description of minor workers: Measurements (n=5): HW 0.52–0.61 (0.58), HL 0.66–0.71 (0.68), SL 0.80– 0.84 (0.81), MDL 0.40–0.44 (0.42), EL 0.13, WL 0.82–0.91 (0.86), PNH 0.30–0.31 (0.30), PNW 0.35–0.40 (0.37), MNH 0.57–0.59 (0.58), PDH 0.26–0.28 (0.27), PTL 0.22–0.30 (0.24), PPL 0.15–0.18 (0.16), PTH 0.14–0.18 (0.16), PPH 0.14–0.16 (0.15), PTW 0.11–0.13 (0.12), PPW 0.19–0.21 (0.19), PSL 0.06–0.08 (0.07), MFL 0.82– 0.90 (0.85), MTL 0.64–0.69 (0.66), CI 79–88 (85), SI 133–154 (140), MDI 70–77 (73), EI 21–25 (22), FI 142–158 (147), PSLI 10–13 (12), LPpI 50–53 (52), DPpI 117–133 (122), PpWI 161–173 (166), PpLI 61–70 (65), PpHI 89– 100 (96). Head shape roundly oval, longer than wide (CI 79–88), sides convex, posterior head margin relatively wide and weakly rounded, occipital carina visible in full-face view, narrow. Mandibles moderately long (MDI 70–77), longitudinally rugulose. Clypeus smooth, sometimes with short lateral carinae present. Face mostly smooth to superficially punctate, several strong oblique malar carinae present, reaching posterior eye level, sometimes with weak punctures in between, sculpture fading posterior of eyes. Scapes relatively long, about 1.2 times longer than head (SI 133–154), when laid back surpassing posterior head margin by about the length of eleventh funicular segment, with coarse, mostly suberect pilosity. Pronotum in profile flatly convex and subangulate, posterior promesonotal process well developed, bluntly subangulate and prominently produced, metanotal groove well developed and impressed, with weak to inconspicuous cross-ribs, propodeum slightly longer than high, in profile declining smoothly or convexly toward spines. Propodeal spines very short to short-triangular and acute, much shorter than distance between their bases (PSLI 14–19). Promesonotum usually smooth to mostly smooth, remainder of mesosoma punctate to weakly punctate. Metafemur relatively long (FI 142–158), metatibia mostly with subdecumbent to suberect pilosity. Postpetiole usually slightly longer than high (LPpI 100–113), on average 1.7 times wider (PpWI 161–173) and significantly shorter than petiole (PpLI 61–70), with ventral process inconspicuous or very small. Dorsum of petiolar node and postpetiole mostly smooth, remainder weakly to superficially punctate. Gaster smooth and shiny. Standing hairs moderately long, abundant, and blunt, with shorter subdecumbent to suberect pilosity. Color light to darker reddish brown, head usually darker. Discussion: Pheidole fervens , described from Singapore , is a widespread invasive species and could be native to the Oriental or the Oceanic region ( Eguchi 2004 , Wilson & Taylor 1967 ). It usually nests in soil or under stones and usually prefers disturbed habitats ( Eguchi 2004 ). On Fiji it was collected in elevations between 1–800 m and tended to inhabit several different habitats from forest edge and mangrove forest to disturbed and undisturbed rainforest. On Mauritius , which seems to be its western distribution limit, this ant was found in the leaf litter of lowland rainforest ( 200 m elevation). As with most other introduced ants, such as P. teneriffana , it is unclear what effect, if any, P. fervens might have on the rest of the local ant fauna. Considering that the ecosystems of the Mauritius islands have been severely altered and disturbed since the arrival of human settlers several hundred years ago, and native species must also contend with the invasions of introduced organisms ( Fisher 2005 , Ward 1990 ), parts of the original ant fauna might have been marginalized or driven to extinction long ago. We speculate that the scarcity of P. fervens specimens in Mauritius ant collections and its presence in the rainforest means that this ant has not yet become an invasive and dominant aggressor toward other ant species. Nevertheless, efforts to further investigate the presence and activity of introduced Pheidole species are worthwhile, especially in the few remaining undisturbed habitats. The workers of P. fervens can be easily confused with those of P. teneriffana . Morphologically the minor workers are best separated by coarse, mostly suberect scape pilosity, impressed metanotal groove, relatively smaller eyes and shorter spines (EI 21–25, PSLI 10–13) in P. fervens versus decumbent to subdecumbent scape pilosity with longer suberect hairs along outer edge, inconspicuous metanotal groove in profile, and larger eyes and longer spines (EI 25–30, PSLI 14–19) in P. teneriffana . The major workers of P. fervens are recognizable by having longer scapes (SI 61–71 versus SI 49–62) and a narrower postpetiole in dorsal view than P. teneriffana (DPpI 133–150 and PpWI 172–195 versus DPpI 146–235 and PpWI 190–247). In P. fervens , the pilosity in the face and on the metatibia is coarser and at least partly suberect, and the punctures on the sides of the face are stronger than the thinner and more decumbent to subdecumbent pilosity and superficial punctures on the sides of the face in P. teneriffana . Additional material examined: MAURITIUS : Brise Mt. , Bambous , 20.3455 S , 57.7547 E , 200 m , rainforest, 27.v.2005 ( B.L. Fisher et al .); La Nicolière Reserve , 06.v.2007 ( M. Madl ) .