The Role of Ground Beetles (Coleoptera: Carabidae) in Monitoring Programmes in Australia
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Ann. Zool. Fennici 35: 163–171 ISSN 0003-455X Helsinki 11 December 1998 © Finnish Zoological and Botanical Publishing Board 1998 The role of ground beetles (Coleoptera: Carabidae) in monitoring programmes in Australia Timothy R. New New, T. R., Department of Zoology, La Trobe University, Bundoora, Victoria 3083, Australia Received 4 May 1998, accepted 6 August 1998 Use of the diverse Australian carabid fauna in environmental assessment is at present restricted, because of lack of ecological and faunistic information and the difficulties of identifying most taxa. They are not yet a core focal group in monitoring studies. In contrast to groups such as ants, in particular, many carabids are usually captured in only small numbers, and functional groups of Australian Carabidae are poorly defined. Al- though a few studies have demonstrated the predominance of particular taxa in local assemblages and their responses to changes in land management, the presence of par- ticular taxa and the richness of assemblages is unpredictable because of lack of knowl- edge of habitat requirements. The general usefulness of carabids as indicators in Aus- tralia is not yet proven. Carabidae are one of several groups of epigaeic invertebrates with potential for incorporation into a portfolio of focal groups for environmental as- sessment, but are still far from being a ‘stand alone’ group in Australia. 1. Introduction vation assessment in Australia, especially of their values in helping to evaluate habitat quality. Most The use of Carabidae (ground beetles) for envi- of the problems of employing carabids result sim- ronmental assessment in Australia has received ply from our ignorance of the group, and of the little attention, and is by no means as common as responses of individual species to habitat change in much of the northern hemisphere, where con- at even very broad levels. As elsewhere, they are siderable ecological interpretation at species and among the widespread groups of epigaeic insects assemblage levels has been undertaken. There, ca- amenable to trapping by relatively simple tech- rabids are one of the most important insect groups niques, appear to show strong relationships with used as indicators in many terrestrial ecosystems particular habitats, and which also occur reason- (Stork 1990, Desender et al. 1994). Despite their ably strongly in heavily altered landscapes. Cara- undoubted values and potential as monitors in bidae, simply, merit increased study to determine some environments, their use in Australia is not their worth as ecological tools in Australia. Such likely to increase substantially during the next few studies must encompass the biology of the more years, at the least. In this paper I explore why this abundant taxa and seek to define the characteris- is so, in the context of a broader summary of the tic carabid assemblages of a variety of vegetation use of terrestrial epigaeic invertebrates in conser- types and microhabitats. 164 New • ANN. ZOOL. FENNICI Vol. 35 2. The Australian Carabidae series of some 50 papers by T. G. Sloane is diffi- cult for a non-specialist to digest. Sequences of The Australian Carabidae are a remarkable ele- papers more recently by B. P. Moore and M. Baehr, ment of the diverse beetle fauna of the isolated in particular, have made notable advances to our island continent, with many phylogenetically im- knowledge of some groups, and their distributional portant taxa. Carabidae are by no means the larg- relationships. Cicindelinae were appraised by Frei- est family of beetles in Australia, but still comprise tag (1979), so that the 29 species of Cicindela L. an impressive, and very approximate, 2500 spe- can be recognised clearly, and the other genera of cies. Many of these are undescribed, although the this small subfamily diagnosed. However, by far listing in the Zoological Catalogue of Australia the majority of Australian Carabidae belong to (Moore et al. 1987) enumerates 266 genera and the Carabinae (with 32 tribes recognised: Law- about 1800 described species, many with addi- rence & Britton 1994). tional synonyms. More recent revisionary studies As with many insect groups, endemism in Aus- have extended the described fauna to slightly over tralian Carabidae is very high. A high proportion 2000 species. Much of the basic descriptive tax- of species is geophilous, although recent studies onomy does not incorporate biological informa- in northern Queensland have greatly increased the tion, and there have been few complementary eco- known diversity of arboreal species (such as the logical studies and surveys of ground beetles. Ba- species of Philipis Erwin: Baehr 1995). Many taxa sic inferences on regional diversity, local species appear to have very restricted distributions. Noto- richness, and distribution patterns of most groups nomus Chaudoir, for example, contains around are fragmentary or non-existent. The detailed tem- 100 described species, all flightless and many lim- plates of species incidence and seasonal patterns ited to forest environments in eastern Australia. taken for granted by entomologists working on In these habitats, there is considerable species turn- carabids in parts of Europe simply are unavailable. over along latitudinal and other gradients, as dem- Likewise, there is relatively little non-special- onstrated by Darlington (1961). ist literature on the family. Matthews (1980) pro- The broad geographical pattern of Australian vided keys to the genera that occur in South Aus- carabids is one of older elements in the south of tralia, and Moore (1980) included a general ap- the country, reflecting persistence of Gondwanan praisal of the family in his book. A rather more elements in the Bassian region and various de- technical account, with keys to tribes, is provided grees of northern incursives (taxa with strong re- by Lawrence and Britton (1994). However, almost lationships to the faunas of Indonesia, Papua New universally for species level studies, the informa- Guinea and, more broadly, the Oriental region) tion needed to identify species is in the primary extending from north to south. However, many literature, or does not exist in any synthesised species appear to be uncommon, and are known form. Some groups, such as Harpalinae, are par- from few specimens and, in some cases, from only ticularly difficult to identify. Even separation to their type locality. Their distributions are essen- generic level is difficult without access to a large tially unknown except in the most general terms, institutional collection and, as for many other and usually lack strong ecological correlates at groups of insects in Australia, the overall taxo- smaller scales. nomic impediment and dearth of secondary guides Ecological specialisations include a substan- largely precludes reliable non-specialist identifi- tial troglobiont fauna, with local taxa in caves in cations of Carabidae. Few larvae are recognisable many different parts of the country — including to species level, and life history data are fragmen- local endemics in Tasmania, New South Wales tary even for many of the most common species. and the Nullarbor Plain. Speotarus princeps, for As Moore et al. (1987) noted, many of the larger example, has been recorded from a single cave in genera have not been subjects of any recent revi- New South Wales, in which recent searches by sion, and contain varying amounts of undetected Eberhard and Spate (1995) failed to locate it. Sev- or undocumented synonymy, in addition to unde- eral obligate cave dwellers are listed as ‘Vulner- scribed taxa. The solid descriptive foundation on able’ on Tasmania’s interim list of threatened in- Australian Carabidae laid earlier this century in a vertebrates (IAC 1994). Many of the intriguing ANN. ZOOL. FENNICI Vol. 35 • The role of ground beetles in monitoring programmes 165 cave-dwelling carabids have been described by uation of any major habitat. The particular groups Moore over the last 35 years. involved will clearly differ in different contexts, Likewise, the flightless forest taxa, both geo- but should preferably incorporate taxa which show philous and arboreal, tend to be highly localised. some ecological complementarity and can be sam- They were incorporated by Monteith (1995) in pled straightforwardly by simple, standardised developing a conservation index for evaluating techniques (New 1993, 1995, 1998). This context and ranking the highly sensitive tropical wet for- is currently receiving considerable attention in est areas of Queensland. However, in those areas, evaluations involving invertebrates in Australia. arboreal taxa (collected by insecticide fogging of In altered landscapes, such as those heavily modi- tree trunks: method summarised by Baehr 1995) fied for intensive agriculture or softwood planta- were the predominant fauna collected. tion forestry (mainly of the exotic Monterey pine, There is little definitive information on carabid Pinus radiata) in the southeast, dramatic changes phenology, simply because surveys and detailed in the epigaeic invertebrate fauna can result. Con- life history studies have only rarely been done, siderable effort has been made to evaluate and even for many of the most abundant species. Near document such changes, and to implement moni- Melbourne, Notonomus gravis (Chaudoir) has been toring systems involving the responses of differ- captured in every month of the year (P. A. Horne, ent invertebrates and invertebrate groups. 1992), but in very small numbers during winter com- However, there is