Ants in French Polynesia and the Pacific: species distributions and conservation concerns Paul Krushelnycky Dept of Plant and Environmental Protection Sciences, University of Hawaii, Honolulu, Hawaii Hervé Jourdan Centre de Biologie et de Gestion des Populations, INRA/IRD, Nouméa, New Caledonia The importance of ants • In most ecosystems, form a substantial portion of a communities’ biomass (1/3 of animal biomass and ¾ of insect biomass in Amazon rainforest) Photos © Alex Wild The importance of ants • In most ecosystems, form a substantial portion of a communities’ biomass (1/3 of animal biomass and ¾ of insect biomass in Amazon rainforest) • Involved in many important ecosystem processes: predator/prey relationships herbivory seed dispersal soil turning mutualisms Photos © Alex Wild The importance of ants • Important in shaping evolution of biotic communities and ecosystems Photos © Alex Wild Ants in the Pacific • Pacific archipelagoes the most remote in the world • Implications for understanding ant biogeography (patterns of dispersal, species/area relationships, community assembly) • Evolution of faunas with depauperate ant communities • Consequent effects of ant introductions Hypoponera zwaluwenburgi Ants in the Amblyopone zwaluwenburgi Pacific – current picture Ponera bableti Indigenous ants in the Pacific? Approx. 30 - 37 species have been labeled “wide-ranging Pacific natives”: Adelomyrmex hirsutus Ponera incerta Anochetus graeffei Ponera loi Camponotus chloroticus Ponera swezeyi Camponotus navigator Ponera tenuis Camponotus rufifrons Prionopelta kraepelini Cardiocondyla nuda Rogeria stigmatica Pheidole fervens ? Carebara atomus Solenopsis papuana Cryptopone testacea Strumigenys godeffroyi Eurhopalothrix procera Strumigenys mailei Hypoponera confinis Strumigenys szalayi Iridomyrmex anceps Tapinoma minutum Monomorium liliuokalanii Technomyrmex vitiensis Monomorium australicum Tetramorium cf. grassii Odontomachus simillimus Tetramorium insolens Paratrechina minutula Tetramorium pacificum Pheidole oceanica Tetramorium tenuicrine Pheidole sexspinosa Tetramorium tonganum Pheidole umbonata Vollenhovia denticulata Platythyrea parallela Indigenous Pheidole fervens species? Indigenous Pheidole oceanica species? Tetramorium Indigenous pacificum species? Monomorium Indigenous antarcticum species? Indigenous ants in the Pacific? • Currently unknown which species are actually native • Are several possibilities regarding the biogeography of these species, each of which has interesting and important implications…. Photo © Alex Wild Indigenous ants in the Pacific? A. Species were introduced by people If true, ants could help in understanding pathways of human migration and/or trade B. Species truly indigenous If true, represents a highly unusual example in the Pacific regarding colonization and adaptive radiation; also implications for conservation of other native arthropods C. Cryptic endemic species? If true, informs understanding of ant dispersal, biogeography and evolution D. Some combination of above E.g., former endemic species may have been driven to extinction by new species introduced by people Invasive ants • Many ants species in the Pacific are clearly non- native (“tramp ants”) • A fraction of these can cause major problems for biodiversity conservation, agriculture, tourism, and even public health (“invasive ants”) • Necessitates thorough surveys as well as effective preventative measures Photos © Alex Wild Ant Surveys: Sampling intensity is important, as are repeat visits pre- vs post-1967 sampling Morrison. 1996. Ecography 19: 73-84. Ant Surveys: Sampling intensity is important, as are repeat visits pre- vs post-1967 Raiatea Rurutu sampling Rimatara Morrison. 1996. Ecography 19: 73-84. How many more species can Pacific islands support? Currently: Hawaiian Islands: approx. 55 spp. Society Islands: approx. 52 spp. Austral Islands: approx. 31 spp. How many more species can Pacific islands support? 60 Currently: Hawaii 50 Hawaiian Islands: c approx. 55 spp. 40 30 Society Islands: 20 approx. 52 spp. Cumulative spe 10 Cumulative species Austral Islands: 0 approx. 31 spp. 1860 1880 1900 1920 1940 1960 1980 2000 Year Year Invasive species Argentine ant (Linepithema humile) Photo © Alex Wild • Reduces native biodiversity (including pollinators, seed dispersers) • Tends pestiferous Hemiptera • Currently in Hawaii (higher elevations) and Rapa Nui (Easter Island) Invasive species Bigheaded ant (Pheidole megacephala) Photo © Alex Wild • Reduces native biodiversity • Tends pestiferous Hemiptera • Currently in Hawaii, Marquesas, Tonga, Samoa, Tahiti (but not rest of Society Is. and Australs) Invasive species Red imported fire ant (Solenopsis invicta) Photo © Alex Wild • Reduces native biodiversity (including vertebrates) • Tends pestiferous Hemiptera • Aggressive with painful sting • Affects economy and quality of life • Currently in California, Australia, China, Taiwan Invasive species Little fire ant (Wasmannia auropunctata) Photo © Alex Wild • Reduces native biodiversity (including vertebrates) • Tends pestiferous Hemiptera • Extremely abundant with irritating sting • Affects economy and quality of life • Currently in New Caledonia, Hawaii, Tahiti, Australia, Vanuatu, PNG, Solomon Islands… Species of Concern White-footed ants (Technomyrmex spp.) Photo © Alex Wild • Tend pestiferous Hemiptera (can impact native plants - Mauritius) • Household pest, nest arboreally • T. albipes and T. difficilis currently in Hawaii, Pohnpei, Palau; T. vitiensis widespread in Pacific Species of Concern Iridomyrmex anceps Photo: AntWeb • Recently found on Mt. Marau, Tahiti • Ecology and impacts unknown • Currently in western Pacific, Fiji, Tokelau, Cook Islands, commonly intercepted in New Zealand Mauruuru! R. Gillespie, G. Roderick, E. Claridge, J.Y. Meyer, and the Gillespie-Roderick Lab at UC Berkeley, A. Wild Délégation à la Recherche, Gouvernement de la Polynésie française UC Berkeley Gump Research Station National Science Foundation and the Margaret C. Walker Fund Ants in the Pacific Monomorium minutum var. liliuokalanii Ants in the Pseudocryptopone zwaluwenburgi Pacific – Pseudocryptopone swezeyi 1930’s Ponera kalakauae Ponera mumfordi Ponera perkinsi Pheidole sexspinosa adamsoni Amblyopone zwaluwenburgi Smithistruma mumfordi Pheidole oceanica var. boraborensis Pheidole oceanica nigriscapa var. tahitiana Oligomyrmex tahitiensis Plagiolepis mactavishi Monomorium rapaense Hypoponera zwaluwenburgi Ants in the Amblyopone zwaluwenburgi Pacific – 1967 Strumigenys mumfordi Oligomyrmex tahitiensis Hypoponera zwaluwenburgi Ants in the Amblyopone zwaluwenburgi Pacific – 1967 Strumigenys mumfordi Oligomyrmex tahitiensis Hypoponera zwaluwenburgi Ants in the Amblyopone zwaluwenburgi Pacific – 1967 Strumigenys mumfordi Oligomyrmex tahitiensis.