Records of the Western Australian Museum Supplement No. 76 A Guide to the Ants of South-western Australia Brian E. Heterick Imprint and publication details page – to come PREFACE Increasingly, invertebrates are being used as indicators of environmental health in various native and altered ecosystems throughout Australia. Among invertebrates that can be utilised in this way, ants are a very suitable indicator group because they are abundant and have high biodiversity, are relatively well known taxonomically, are easy to collect and identify, and are sufficiently robust to be able to be handled without special preparation. They are also reasonably sensitive to environmental disturbance. Assessing the progress of revegetation of minesites is one of the more common applications where ants can be used as indicators of success. However, to this point of time, there has been no single authoritative reference source for the ant species found in Western Australia, including those collected in rehabilitated minesites and other programmes involving sampling of ants. This present work attempts a comprehensive overview of all the described ant species currently recognised from the south-west of Western Australia, specifically, the South-West Botanical Province (a phytogeographic zone). Also included are the many undescribed species, or those of uncertain taxonomic status, recognised by the Curtin University of Technology. The latter are indicated in this monograph by voucher numbers. Taxonomic keys will enable an enquirer to arrive at subfamily, genus and species name (if described) for any particular worker ant specimen. Although this volume covers the ants of South-Western Australia, many of these species are also present in the Pilbara, where Rio Tinto Iron Ore has most of its mining interests. We are therefore proud to be associated with the sponsorship of this important work. Warwick Smith Managing Director Expansion Projects Rio Tinto Iron Ore TABLE OF CONTENTS Introduction ..................................................................................................................................................................... 7 Botanical Districts within the SWBP in relation to the ant fauna............................................................................. 8 Nomenclature .................................................................................................................................................................. 9 What’s in a name? ........................................................................................................................................................... 9 What makes an ant an ant? .......................................................................................................................................... 12 Where and how do ants live in the SWBP? ............................................................................................................... 12 Pest ants and tramp ants .............................................................................................................................................. 13 Ants as bioindicators .................................................................................................................................................... 15 Key to the ant subfamilies of the South-West Botanical Province ......................................................................... 16 Plates ............................................................................................................................................................................... 20 Key to the ant genera of the South-West Botanical Province .................................................................................. 28 Key to the ant species of the South-West Botanical Province ................................................................................. 42 A note on taxonomic decisions made in this work .................................................................................................. 42 Species key and discussion of species ........................................................................................................................ 43 Appendix 1: Ant species and morphospecies recorded from the SWBP ............................................................ 180 Appendix 2: Ant species and morphospecies recorded from the SWBP placed by botanical district .................................................................................................................................. 187 Glossary of terms used in this work ......................................................................................................................... 198 References ..................................................................................................................................................................... 202 Acknowledgements .................................................................................................................................................... 206 A Guide to the Ants of South-western Australia 7 A Guide to the Ants of South-western Australia B. E. Heterick1 Department of Environmental and Aquatic Sciences, Curtin University of Technology, Bentley, Western Australia 6102, Australia. E-mail: [email protected] Abstract – This work constitutes a review of what is known about the ants of the South-West Botanical Province, a region internationally recognized as having a megadiverse flora. The ant fauna is also highly diverse, including no fewer than 12 subfamilies, 61 genera and at least 500 species. The author includes three illustrated taxonomic keys to the 13 Australian subfamilies, 61 genera and the workers of 497 morphospecies, respectively. The last- mentioned key includes all species described for the region, but excludes a tiny handful that cannot be identified with assurance because the information in the original description is too scant or the type specimens have been lost. Also included in the species key are workers of all the other morphospecies known from the Province that appear to constitute recognizable species, and are at present allocated voucher numbers in the Curtin Ant Collection. Many of the south-west ants (almost 50%) appear to be undescribed. All of the above ant taxa, described or undescribed, are included in a discussion following the keys. Novelties mentioned in the key to genus include the first WA record of the genus Mayriella, and the genus Rogeria (tentatively assigned to two spe- cies). The genus Anillomyrma is removed from the WA checklist, as the local species is now considered a Monomorium. Four species (Iridomyrmex argutus Shattuck (under Iridomyrmex innocens Forel), Iridomyrmex occiduus Shat- tuck (under I. innocens Forel), Pachycondyla (Trachymesopus) clarki Wheeler (under Pachycondyla (Trachymesopus) rufonigra Clark), and Crematogaster perthensis Crawley (under Crematogaster frivola (Forel)) here pass into synon- ymy, and Tapinoma rottnestense Wheeler becomes Doleromyrma rottnestensis (Wheeler) in a new combination. Also included in this work are short discus- sions on a variety of topics not well covered in the Australian ant literature, a comprehensive glossary of terms, a complete ant check list (Appendix 1) and a table showing known ant species distributions within the seven botanical dis- tricts that together make up the South-West Botanical Province (Appendix 2). Key words: South-West Botanical Province, ant fauna, taxonomic keys INTRODUCTION to the author’s knowledge, sixty-one described ant genera, including almost 500 identifiable The phytogeographic region in Western Australia morphospecies, have been recorded for this known as the South-West Botanical Province, Province. These are the species that appear in the (hereafter, SWBP) (Figure 1), is well known as a key to worker ants for the Province. Over half-a- hotspot of mega-diversity for vascular plants (e.g. dozen additional names for ants described from Beard et al. 2000). However, this region also has a the region can be found in the literature, but their rich ant fauna, with, for example, approximately status is uncertain and the bulk of these are likely ten times the number of ant species found in the to become junior synonyms in future revisions. United Kingdom. Twelve of the thirteen subfamilies The paucity of novel taxa now being identified currently recognized as occurring in Australia can by Curtin staff and students, along with myself, be found in the SWBP. The thirteenth subfamily, suggests that additional species to those covered Aenictinae, has been recorded south-east of in this monograph are likely either to be very rare, Newman (Pilbara region) and may well occur or at the fringes of a distribution that mostly lies in the far north of the SWBP. For this reason, the outside of the SWBP. key to subfamilies provided below includes the Despite the high ant biodiversity at a species Aenictinae. level, only six of the twelve subfamilies are At a generic and species level, the ant fauna is represented by two or more genera. On the generic also very diverse: the actual number of species level, several important recent changes from the possibly exceeds well over 500. At the present time, genera discussed in Shattuck (1999) are noted here: 8 Brian E. Heterick Figure 1 The South-West Botanical Province, showing major cities in the Province. Inset: The South-West Botanical Province in relation to the rest of the Australian