Pheidole sexspinosa

In Singapore, this species has been found in mangrove back forest or swamp forest. Colonies were found nesting inside a decayed stem of Rhizophora sp. and cable roots of Excoecaria agallocha. The latter is a common mangrove tree species in Singapore, and secretes milky latex, which is toxic to animals including insects (Mendhulkar et al., 2017; Wang et al., 2018).

Distribution
Wang et al. (2018): Pheidole sexspinosa can be found throughout the Oceanian realm sensu Holt et al. (2013), including, New Guinea, and the Solomon, Palau, Caroline, Fiji, Samoa, Tuvalu, Austral, Society and Marquesas Islands (antmaps.org, accessed on 24 October 2018; Guénard et al., 2017). The only record in Fiji is for a single worker (AntWeb v7.53, CASENT0194651) – this might indicate an incipient or transient occurrence of the species (Sarnat & Economo, 2012). It has also been recorded once in New Zealand as an exotic human-introduced species (Ward et al., 2006). With its discovery from Singapore in this paper, the distribution range of this species can thus be expanded to include the Oriental realm as well.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Cook Islands, French Polynesia, Micronesia (Federated States of), New Guinea, Niue, Palau, Samoa, Singapore, Solomon Islands, Tokelau, Tuvalu, Vanuatu, Wallis and Futuna Islands.

Nomenclature

 *  sexspinosa. Pheidole sexspinosa Mayr, 1870b: 977 (s.w.) TUVALU. Combination in P. (Pheidolacanthinus): Mann, 1919: 307. Senior synonym of adamsoni: Wilson & Taylor, 1967: 52. Current subspecies: nominal plus biroi, fuscescens.
 * adamsoni. Pheidole (Pheidolacanthinus) sexspinosa subsp. adamsoni Wheeler, W.M. 1932c: 157 (s.w.q.m.) FRENCH POLYNESIA (Marquesas Is). Junior synonym of sexspinosa: Wilson & Taylor, 1967: 52.

Type Material

 * Pheidole sexspinosa – syntype, major, CASENT0919761, Tuvalu, Oceania, only part of head and thorax being intact.
 * Pheidole sexspinosa adamsoni – cotype, major, CASENT0249104, Marquesas Is.; cotype, major, LACMENT182082, Marquesas Is.
 * Pheidole sexspinosa biroi – syntype, major, CASENT0904306, New Guinea; syntype, minor, CASENT0904307, New Guinea.