Ants (Hymenoptera: Fonnicidae) of Samoa!

The ants of Samoa have been well studied compared with those of other Pacific island groups. Using Wilson and Taylor's (1967) specimen records and taxonomic analyses and Wilson and Hunt's (1967) list of 61 ant species with reliable records from Samoa as a starting point, we added published, unpublished, and new records of ants collected in Samoa and updated taxonomy. We increased the list of ants from Samoa to 68 species. Of these 68 ant species, 12 species are known only from Samoa or from Samoa and one neighboring island group, 30 species appear to be broader-ranged Pacific natives, and 26 appear to be exotic to the Pacific region. The seven-species increase in the Samoan ant list resulted from the split of Pacific Tetramorium guineense into the exotic T. bicarinatum and the native T. insolens, new records of four exotic species (Cardiocondyla obscurior, Hypoponera opaciceps, Solenopsis geminata, and Tetramorium lanuginosum), and new records of two species of uncertain status (Tetramorium cf. grassii, tentatively considered a native Pacific species, and Monomorium sp., tentatively considered an endemic Samoan form). SAMOA IS AN ISLAND CHAIN in western Polynesia with nine inhabited islands and numerous smaller, uninhabited islands. The western four inhabited islands, Savai'i, Apolima, Manono, and 'Upolu, are part of the independent country of Samoa (formerly Western Samoa). The eastern five inhabited islands, Tutuila, Aunu'u, Ofu, Olosega, and Ta'u, are part of American Samoa, an unincorporated territory of the United States. The ants of Samoa have been well studied compared with those of other Pacific I Financial support was provided by American Samoa Community College; the Cooperative Research, Education, and Extension Service of the U.S. Department of Agriculture (CRIS Accession no. 164128, administered by the American Samoa Community College); Wheaton College; and Florida Atlantic University. Manuscript accepted 17 March 2003. 2 Wilkes Honors College, Florida Atlantic University, 5353 Parkside Drive, Jupiter, Florida 33458 (phone: 561799-8648; fax: 561-799-8602; E-mail: [email protected]). 3 Community and Natural Resources, American Samoa Community College, P.O. Box 5319, Pago Pago, American Samoa 96799. Pacific Science (2003), vol. 57, no. 4:409-419 © 2003 by University of Hawai'i Press All rights reserved island groups, prompting Wilson and Taylor (1967:4) to feel "confident that a nearly complete faunal list could be made for the Samoan Islands." Samoa is of particular interest because it is one of the easternmost Pacific island groups with a substantial endemic ant fauna. Wilson and Taylor (1967:1) concluded that "few if any ant species are native to the islands east of Rotuma, Samoa, Tonga, and New Zealand. This part of Polynesia has been populated by tramp species" (i.e., species that associate with humans and are spread by human commerce). In this study, we combine published, unpublished, and new records from Samoa, increasing the list of ants known from Samoa to 68 species.