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Browsing Environment Institute Leaders publications by Advisors "Austin, Andrew Donald"
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Item Open Access The ecology of key arthropods for the management of Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae) in Coonawarra vineyards, South Australia.(2008) Paull, Cate; Austin, Andrew Donald; Schellhorn, Nancy A.; School of Earth and Environmental Sciences : Ecology and Evolutionary BiologyThere is currently little knowledge about the dynamics of invertebrates in Australian viticultural ecosystems. This study was conducted in Coonawarra vineyards over three seasons (years) and has focused on identifying natural enemies, their seasonal phenology, multiple species interactions, and potential for the suppression of the pest lepidopteran Epiphyas postvittana (Tortricidae). The work presented in this thesis shows that endemic natural enemies have far greater potential to control E. postvittana than has been realised. An initial survey identified a diverse and abundant range of potential natural enemies. Of these, the species most likely to attack E. postvittana include a predatory mite Anystis baccarum and a number of hymenopteran parasitoids. The most abundant parasitoid in the vineyards was a braconid, Dolichogenidea tasmanica. Understanding the characteristic behaviour of parasitoids in response to host density can help to gauge their potential for pest suppression. The results of large-scale field experiments showed that the response of D. tasmanica to the density of E. postvittana was inversely density-dependent, and that parasitism was consistently higher in Cabernet Sauvignon compared with Chardonnay varieties. Despite the fact that interactions among multiple species of natural enemies can increase or decrease pest suppression, particularly when they share a common prey/host, few multispecies interactions have been investigated. Laboratory studies identified a novel interaction between the predatory mite A. baccarum an abundant predator in the vine canopy, the parasitoid D. tasmanica and host E. postvittana larvae. Although A. baccarum readily ate E. postvittana eggs and free roaming larvae, they could not access larva in their silk leaf rolls. However, the addition of D. tasmanica significantly increased predation of E. postvittana larvae, by altering the behaviour of host larvae and increasing their vulnerability to the mite. Experiments conducted at a landscape level in the Coonawarra showed that D. tasmanica was also present in habitat other than vineyards including native vegetation. However, it was not present in highly disturbed habitats. Although the exact mechanism for this remains unknown, results indicate that viticultural practices and resources in the surrounding landscape can influence the presence of parasitoids. Together, the findings presented in this thesis make a significant contribution towards developing sustainable pest management in Australian viticulture.Item Open Access Ecology of the Fergusonina fly and Fergusobia nematode gall association in South Australia.(2008) Head, Elise; Riley, Ian Timothy; Davies, Kerrie Ann; Taylor, Gary Stewart; Austin, Andrew Donald; School of Agriculture, Food and Wine : Plant and Food ScienceAttempts were made to grow Fergusobia nematodes in a dual aseptic culture with Eucalyptus camaldulensis. Callus tissue was grown from E. camaldulensis stem pieces in aseptic conditions. Calli were prone to deterioration after 14 days unless transferred to fresh growth medium. Lower levels of solutes (25% Murashige and Skoog salts, 25% plant vitamins and 0.5% sucrose) were more successful than published concentrations. Fergusobia J2 nematodes were surface sterilised with either Hibitane or washed with water to prepare them for inoculation of callus (Hay, 1994). Fergusobia subsequently recovered from plates of callus were all dead, which raised questions of how the nematodes are suited to Murashige and Skoog salt solutions. The survival of Fergusobia in aqueous solutions was then observed. It has been assumed that Fergusobia live about 2 days after dissection. Amphimictic nematodes from E. camaldulensis axial bud galls were used for a survival study. Nematodes lived for as long as 12 days in fresh tap water and 11 days in 1% M.S. solution. They were more active in tap water than in 1% M.S. solution. Nematodes in a dish together with dissected gall material died within 2 days. Nematodes in a separate dish with fresh tap water and clean gall fibres were observed to gather around the fibres. Observations of Fergusobia could be made within fresh solutions providing deteriorating gall tissues were removed from the dish. Gall production was attempted on E. camaldulensis grown in the glasshouse. These tree saplings were pruned to encourage new growth and periodically treated for infestations of scale insects leading to growth of sooty mould. Two forms of cage construction were used: (1) 1 m ³ screened cages and (2) acetate sleeves as used by Goolsby et al., 2000. Within the 1 m ³ cages containing flies, the growing points on saplings were blackened, possibly due to over-exploitation by ovipositing flies. One growing point caged in an acetate sleeve showed oviposition scars but did not produce a mature gall. Production of galls in the glasshouse was hindered by a lack in coincidence of flies emerging from mature galls and the flush of new growth following pruning. The production of galls within the glasshouse was not achieved. The phenology of E. camaldulensis, a host for the Fergusonina/Fergusobia mutualism, and gall ecology were observed in a two-year, non-destructive, field study in the Urrbrae Wetlands, Adelaide, South Australia. Tree growth and gall development was observed in the lower regions (0 – 2 m) of young trees. Three bud forms, terminal leaf bud, axial leaf bud and flower bud galls were monitored on the trees. The densities of galls were highly seasonal. Greatest density of growing points, axial leaf bud and flower bud galls occurred mostly during mid-winter to spring, whereas that of terminal leaf bud galls occurred during mid-spring to summer. Galling of flower buds did not appear to influence flowering and more flower buds and flowers occurred in the second year of the study as the trees matured. Trees mostly had medium (30-70%) levels of leaf damage, but there were seasonal trends in damage levels. Low scores for leaf damage were associated with increases in flower bud and flower production. Leaf damage, including sooty mould, appeared to increase during the cooler winter months. There were no significant seasonal relationships between levels of leaf damage and either growing point density or the occurrence of galls. When trees were compared with each other, those with lower leaf damage were more likely to have more growing points. The appearance of the canopy and the likelihood of a tree to have galls varied greatly between the trees. One tree was particularly susceptible to leaf attack, rarely had new leaves and produced no mature galls during the study. The colouring of leaves varied between trees, which indicates possible genetic variations causing some trees to be more likely hosts for Fergusonina/Fergusobia. Both new vegetative growth and terminal leaf bud galls were concentrated on the northern and eastern quadrants. Axial leaf bud and flower bud galls occurred more on the western or southern quadrants where they were possibly more protected from sun exposure on the northern or eastern quadrants. Axial galls on the northern side of one tree became reddened while those in the southern and western quadrants remained green. Reddening of axial galls may increase their likelihood of parasitism and predation by birds. Each of the three gall forms occurred within certain positions in the canopy. The tree host resource is partitioned effectively, with the three gall forms occurring on three different host structures. Additionally, the two vegetative forms terminal leaf bud and axial leaf bud galls occur on different shoot regions and in different seasons. The numbers of the galls is probably also affected by biotic and climatic influences. Parasitism, plant canopy shading, nutrient levels and host genetics are possible influences. Assuming an interval of 4 weeks between oviposition and first observation within the current study, terminal leaf bud galls had an average longevity of 11 weeks and axial leaf bud galls an average longevity of 14 weeks. Flower bud galls had longevities of 14 to 27 weeks from oviposition to senescence, assuming an interval of 6 weeks between oviposition and first observation within the current study. Flowers and flower buds occur irregularly within the eucalypts so it would be advantageous for flies and nematodes developing within flower bud galls to have extended or variable longevities to allow fly emergences to coincide with new flower buds. Not all of the galls recorded matured to produce adult flies. Nearly half of the terminal leaf bud galls initiated were aborted, recorded as absent, parasitised or eaten (45% of initiated galls). Of the three gall forms, they were the most prone to obvious parasitism and as many as 12 hymenopteran species have been reared from terminal leaf bud galls on E. camaldulensis (Taylor et al., 1996). These galls obviously provide a resource for many species within multiple trophic levels. Fourteen percent of axial leaf bud galls were absent or eaten and birds were seen breaking off and feeding on the galls. More than half (55%) of the initiated flower bud galls disappeared during the period of observation, possibly due to the foraging of birds. Destructive sampling and rearing out of parasitoids from both axial leaf bud and flower bud gall forms is needed to establish what species exist within them. Terminal leaf bud galls ranged from 7.5 to 30.1 mm in diameter and 10.0 to 43.6 mm in length. Flower bud gall size varied, with the largest being 15.0 mm by 22.3 mm. Axial leaf bud galls, ranged from 2.6 to 13.0 mm in diameter and length ranged from 2.3 to 10.5 mm. The larger axial leaf bud galls were nodular and appeared to have multiple locules. Destructive sampling and rearing out of flies is needed to establish the relationship between size and numbers of flies emerging. Terminal leaf bud galls increased in size, including many locules and exit holes per gall. Axial leaf bud galls were much smaller than the terminal leaf bud galls and 99% had only one to three exit holes. The rounded shape and presence of few locules within the axial leaf bud galls indicate that this form is limited to a shape and size producing few flies. The observation of greater size of terminal leaf bud galls suggests that these galls may have multiple foundresses. Twelve of the 13 flower bud galls with exit holes had either one or two holes. In flower bud galls on E. camaldulensis. the operculum remains sealed and the characteristic Fergusonina “window” appears at the side of the flower bud before fly emergence through a single hole. Destructive sampling is also necessary to determine parasitism of each of the gall forms.Item Open Access Modes of speciation in subterranean diving beetles from a single calcrete aquifer in Central Western Australia.(2010) Bradford, Tessa Margaret; Cooper, Steven John Baynard; Austin, Andrew Donald; School of Earth and Environmental Sciences : Ecology and Evolutionary BiologyCalcrete aquifers from the Yilgarn region in central Western Australia‘s arid zone contain a highly diverse range of obligate groundwater invertebrate species (stygofauna), with many endemic to single calcretes. Phylogenetic studies on the diving beetles from the Yilgarn calcretes suggest a scenario of invasion of the subterranean environment by several surface dwelling ancestors during aridification of the region since the Miocene. This system is ideal for examining modes of speciation within a closed calcrete body and in particular the relative roles of allopatric, parapatric and sympatric speciation in the generation of diving beetle (Dytiscidae) species diversity. Previous phylogenetic analyses have identified 13 independent cases of sympatric sister species pairs of large and small diving beetles in separate calcretes, suggesting the potential for their speciation in sympatry as a result of ecological niche partitioning. A single calcrete at Sturt Meadows contains a sympatric sister triplet of large and small diving beetles (Paroster macrosturtensis, P. mesosturtensis, P microsturtensis), and can be accessed by an extensive grid of mineral exploration bores (3.5km², 115 bores), allowing intensive sampling for population genetic studies and biodiversity assessment. Comparative phylogeographic analyses by others on these Paroster beetle species found no evidence for long term allopatric processes operating within the calcrete, although any fragmentation event that could have led to the evolution of the three beetle species may not have persisted post-speciation, and thus would not been seen in their gene genealogies. The aim of this study was to investigate the possibility that the three beetle species at Sturt Meadows may have evolved by sympatric speciation due to trophic niche partitioning. Two main approaches were used to achieve this aim. First, whether the different beetle species have different trophic niches was determined and, second, whether micro-allopatric processes, such as fragmentation events, may have led to the evolution of the three beetle species was investigated. To detect evidence for such fragmentation events, a comparative phylogeography of chiltoniid amphipods in the Sturt Meadows calcrete was undertaken. A DNA barcoding framework was established for the macro-invertebrates in the Sturt Meadows calcrete, in order to obtain sequence information on potential prey groups for the diving beetles. A 623-bp fragment of the mitochondrial cytochrome c oxidase 1 (COI) gene was amplified from stygofauna plus terrestrial organisms that were found in the calcrete. Phylogenetic analyses revealed the existence of 12 divergent monophyletic groups of haplotypes, including three unrelated lineages of chiltoniid amphipod that are morphologically cryptic. Allozyme analyses on the amphipods showed them to be three species that can be separated at multiple allozyme loci. Spatial variation in genetic diversity was assessed for the chiltoniid amphipods, enabling a comparative phylogeography of the three species across the bore field. There was no common pattern in the gene trees of the amphipod species, so no evidence for three isolation events in the diversification of the diving beetles at this site. However, high haplotype diversity coupled with low nucleotide diversity, plus signatures of population expansion and isolation by distance in two out of three species, match previous findings for diving beetles at the same site and indicate the potential for micro-allopatric evolutionary processes to have operated within the calcrete. Isolation of populations in pockets of favourable habitat (refugia) within the calcrete followed by expansion events, are proposed as the most likely generator of population genetic diversity, and are thought to be related to water level changes in the aquifer. Trophic niche partitioning in the sister triplet of large and small Paroster diving beetles and their larvae was investigated by molecular amplification of small fragments of the COI gene identified by the barcode. Amphipods (Chiltoniidae) and copepods (Harpacticoida, Cyclopoidea) were chosen for the analysis as they were the most abundant potential prey items in the calcrete. There was not complete trophic partitioning in the adult beetles, with all three species feeding on amphipods and copepods. As the trophic analysis was molecular, differences in size of the prey were not tested for. There was some evidence for preferential feeding on particular prey species by the adult beetle species, however, small sample sizes precluded making comparisons between their larvae. It is thought that in the impoverished environment of the aquifer, the adult beetles are scavengers and opportunistic feeders, as well as active predators. Stable isotope analysis confirmed that the three diving beetle species are feeding on similar food items, and indicated a separate source of carbon and nitrogen to the tree roots as the basis of the food web of the calcrete. In summary, there was no evidence for complete trophic niche partitioning in the adult diving beetles of different sizes that could have led to their speciation in sympatry. Any further investigation of trophic differences needs to concentrate on preferential feeding in the adults, and the trophic niche of the beetle larvae which are active predators. The potential for micro-allopatry in the diversification of the different sized diving beetles at Sturt Meadows has been identified, through congruence in current population genetic patterns for the amphipods and the diving beetles. Stygofauna in the calcrete have high genetic diversity, which is thought to be the result of historical water level fluctuations leading to frequent population bottlenecks, followed by range expansion after aquifer recharge. Identification of at least 12 macro-invertebrate species in a single calcrete increases the total number of stygobytic and troglobytic species discovered in the Yilgarn, and has enabled estimates to be made of possible numbers of subterranean species in the region still to be discovered. The presence of large and small dytiscid beetles in multiple calcretes that are sympatric sister species still points to some common ecological niche differentiation within the calcrete environment. It is hypothesized that there could be depth partitioning in the different sized diving beetles related to their oxygen requirements. The population genetic and ecological data generated at Sturt Meadows provide a baseline for the Yilgarn calcretes. Extending such a study to examine spatial and ecological differentiation in sympatric sister species of subterranean diving beetles across multiple calcretes, would be a powerful approach in the investigation of modes of speciation.Item Open Access Phylogenetics and biogeography of Australian subterranean Parabathynellidae.(2012) Abrams, Kym; Guzik, Michelle Tanya; Austin, Andrew Donald; Cooper, Steven John Baynard; King, Rachael Amy; School of Earth and Environmental SciencesThe putatively ancient subterranean crustacean family Parabathynellidae has been poorly studied, in part because of the problem of obtaining material from difficult to access subterranean habitats in which they live. Further, the systematics of the group has been complicated by their generally simplified morphology and isolated descriptions of new taxa in the absence of any phylogenetic framework. This thesis provides a comprehensive molecular systematics framework for Australian Parabathynellidae, which is used to explore phylogenetic relationships amongst parabathynellids, their diversity, some aspects of character evolution and their biogeographic history within Australia. In addition, taxonomic descriptions are provided for the first parabathynellid species from South Australia. For the first data chapter molecular sequence data from the mitochondrial cytochrome c oxidase subunit 1 (COI) and 18S rRNA genes were generated in order to examine phylogenetic relationships amongst Australian genera and assess the species diversity of this group within Australia. The resultant phylogenetic framework, in combination with an ancestral state reconstruction analysis, was used to explore the evolution of two key morphological characters previously used to define genera, and assess the oligomerization principle (i.e. serial appendage reduction over time), which is commonly invoked in crustacean systematics. The ancestral state reconstruction analysis was also used to determine whether there has been convergent evolution of appendage numbers during the evolution of Australian parabathynellids. Phylogenetic analyses revealed that species of each known genus, defined by traditional morphological methods, were monophyletic, suggesting that the commonly used generic characters are robust for defining distinct evolutionary lineages. These analyses also revealed a remarkable diversity of parabathynellids. Additionally, ancestral state reconstruction analysis provided evidence for multiple cases of convergent evolution for the two morphological characters evaluated and contradicted the conventional view of parabathynellid evolution, which assumes that more simplified taxa (i.e. those with fewer-segmented appendages and setae) are derived and more complex taxa are primitive. The third chapter focuses on South Australia, where phylogenetic analyses revealed a previously unknown diversity of parabathynellids from South Australia, and a complex set of relationships with the New South Wales and Western Australian fauna. Additionally, the first parabathynellid genus from South Australia, Arkaroolabathynella gen. nov, is described and a key to and checklist of Australian parabathynellid genera is also provided. The final data chapter used an expanded dataset to investigate the geographic distribution, history and evolutionary relationships of extant parabathynellids between subterranean bioregions in Australia. This study found evidence for significant regional biogeographic structuring of parabathynellids at the genus and species levels, indicating a long and complex evolutionary history for these animals in Australia, likely shaped by fluctuating climates throughout the continent’s development. The high incidence of regional endemism for parabathynellids is signifcant because it confirms the poor dispersal capability of these animals, which makes them particularly vulnerable to disturbance or destruction of their subterranean habitats.Item Open Access Phylogenetics of the Cotesia flavipes species complex: towards the effective control of stemborer pests in Australia.(2010) Muirhead, Kate; Austin, Andrew Donald; School of Earth and Environmental SciencesThe Cotesia flavipes species complex of parasitoid wasps are economically important worldwide for the biological control of lepidopteran stemborers. The complex currently comprises three species: Cotesia flavipes Cameron, C. sesamiae (Cameron) and C. chilonis (Matsumura), which appear morphologically similar. Despite their economic importance, considerable confusion surrounds the identity of species and host-associated biotypes. Differences in the biology and variation in host range of geographic populations have generally been interpreted as genetic divergence among strains, but direct genetic evidence is lacking. In Australia, several stemborer pests in neighbouring countries have been identified as significant threats to the sugar industry. However, the status of C. flavipes in Australia is unknown. To examine the genetic variation among worldwide populations of the C. flavipes complex and investigate the status of the Australian C. flavipes-like species, a pilot study based on 21 geographic populations of the complex and four outgroups was carried out using partial sequence data generated for mitochondrial gene regions, 16S rRNA and COI. Phylogenetic analyses supported the monophyly of the complex and the existence of genetically divergent populations of C. flavipes and C. sesamiae. The geographically isolated Australian haplotypes formed a distinct lineage within the complex and were ~3.0% divergent from the other species. Based on molecular, morphological and preliminary investigations into biological differences, the Australian species Cotesia nonagriae Olliff stat. rev. was redescribed and formally removed from synonymy with C. flavipes. Investigations of biology and behaviour of C. nonagriae on the native stem borer host, Bathytricha truncata (Walker) (Noctuidae) revealed that duration of the larval stages and adult longevity of C. nonagriae were longer than previously recorded for other members of the species complex. In addition, C. nonagriae oviposited an average of over 100 eggs into each host, almost three times more than for other species in the C. flavipes complex (30-40). During microhabitat location, both naïve and experienced females demonstrated a strong response towards the plant host complex, with experienced wasps benefiting by having a more rapid response time to infested than noninfested plants. Genetic variation and relationships among the complex were further studied by generating nucleotide sequence data for two partial mtDNA gene regions (COI, 16S) and three anonymous nuclear loci (CfBN, CfCN, CfEN) among 42 worldwide populations within the C. flavipes complex and three outgroups. Phylogenetic reconstructions provided strong support for the monophyly of the complex and the presence of at least four species, C. chilonis (from China and Japan), C. sesamiae (from Africa), C. flavipes (originating from the Indo-Asia region but introduced into Africa and the New World), and C. nonagriae (from Australia and PNG). Although there was geographic variation within species, the analyses did not support the overall separation and monophyly of clades associated with different host species. Members of the complex habour polydnavirus (PDV) symbionts, which play a key role in determining host range by host immune suppression during the course of parasitoid development. A worldwide phylogeny of the C. flavipes complex PDV CrV1 locus was determined to investigate cophylogeny between wasps and their PDV symbionts. The results showed that there were numerous PDV CrV1 haplotypes within worldwide populations. However, not all coevolutionary analyses supported the cophylogeny between wasp and PDV trees. Phylogenetic incongruence was most likely a result of the ability of PDVs to coevolve with host resistance through a process of natural selection, whereas the wasp genes were not under selection. The most important result of this study was the implication for the use of the CrV1 locus as a virulence marker in biological control.Item Open Access The reproductive ecology of two terrestrial orchids, Caladenia Rigida and Caladenia tentaculata.(2010) Faast, Renate; Facelli, Jose Maria; Austin, Andrew Donald; School of Earth and Environmental Sciences : Ecology and Evolutionary BiologyThe reproductive outcome of plants is often determined by a multitude of interacting factors operating at both the plant level and the population level. For many plants, fruit production and the subsequent release of seeds are paramount for the persistence of the species. Understanding the processes that influence variation within and among populations is therefore crucial for the successful long-term management of threatened plants. While abiotic factors such as resource availability and environmental conditions can influence seed production directly through their effects on plant growth, biological interactions such as those between plants and pollinators or herbivores can be equally important. The relative intensity and direction of such interactions are often determined by the nature of the plants themselves, or by characteristics of the plant population or the habitat in which it occurs. This thesis examines the processes that influence spatio-temporal variation in the reproductive success of two terrestrial orchids, Caladenia rigida and Caladenia tentaculata. The study was carried out over three years (2005 – 2007), in several populations located in the Mount Lofty region of South Australia. A detailed investigation of the pollination strategy employed by C. rigida revealed that this species is a generalist, being pollinated by a suite of food-seeking insects, possibly attracted by the presence of small amounts of nectar. Successful pollination and seed release for C. rigida was highly variable across space and time. Furthermore, both measures were consistently higher than for the sexually deceptive species, C. tentaculata, leading to the suggestion that the highly specialised pollination syndrome of the latter species may place it at a reproductive disadvantage. Pollination success of C. rigida was influenced by the height of flowers, but not by the local density of conspecifics. Small populations of C. rigida did not produce capsules when environmental conditions were stressful, suggesting that resource availability may indirectly restrict reproductive success by limiting the availability of pollinators. Poor seed quality in some populations may also be attributed to reduced population size. Both orchid species were subject to intense levels of vertebrate florivory and capsule predation, leading to significant reductions in seed output. A herbivore exclusion experiment was carried out to help elucidate the size and type of herbivores, and video surveillance identified birds as a predominant florivore in some populations. The intensity of florivory varied within and among populations, as well as among years, in response to several factors including flower height, the local density of conspecifics, concealment amongst neighbourhood vegetation and proximity to the habitat edge. Spatio-temporal variation in seed release was thus the net outcome of processes acting on both mutualistic and antagonistic interactions. This work provides valuable baseline data of factors that influence the reproductive ecology and, hence, population dynamics of Caladenia species. Implications for the conservation and management of threatened populations are discussed, with respect to both short-term and long-term goals. The thesis is presented as a series of five manuscripts. Two of these have been published, and the remaining three have been prepared for submission as publications.Item Open Access The seasonality, diversity and ecology of cavernicolous guano dependent arthropod ecosystems in southern Australia(2006) Moulds, Timothy A.; Austin, Andrew Donald; Jennings, John; School of Earth and Environmental SciencesGuano deposits in caves form a rich food resource supporting diverse arthropod communities. Guano piles consist of distinct micro - habitats, fresh, moist, highly basic guano and older, dry, slightly acidic guano. Micro - habitat variation is strongly controlled by seasonal guano deposition that, in turn, effects the structure of arthropod communities. The maternity chamber of Bat Cave, Naracoorte, South Australia, contains extensive guano deposits supporting 38 species from three classes and 12 orders. This community was studied to determine spatial and temporal variation of arthropod communities, and biogeographic relationships between different regions in Australia. Species richness forms a positive linear relationship with pH, in situ moisture content and guano deposition. Many species show strong associations with fresh guano and hence are strongly seasonal, although some species are present throughout the year. Arthropod community structure in winter was found to be more closely related to prior summer arthropod structure than to subsequent seasons. Starlight Cave near Warrnambool, western Victoria, the only other maternity site for Miniopterus schreibersii bassanii, contained 43 species from 39 families and 14 orders. Seven species are common to both caves. The community structure of Starlight Cave was found to be more homogeneous than Bat Cave with samples clustering by season rather than sample year as was the case at Bat Cave. Different cave morphology was found to significantly alter the micro - habitat conditions and, hence, community structure in Starlight Cave compared with Bat Cave. Migration of guano associated arthropods at local, regional and continental scales was assessed using mtDNA and allozyme electrophoresis the pseudoscorpion genus Protochelifer as a model organism. Phylogenetic tree reconstruction revealed a wide geographic distribution of cavernicolous species across southern Australia. Cave colonisation is believed to have occurred only once, followed by dispersal to the Nullarbor Plain and other caves in south - eastern Australia. Dispersal was possibly phoretic on cave bats or occurred prior to aridification of surface environments that currently restricts migration. The distribution of guano - associated arthropods from arid, semi - arid and monsoonal karst areas in Australia are compared with temperate south - eastern Australia. Different climatic areas show large biogeographical differences in community structure, although similar families ( Urodinychidae, Reduviidae, Anobiidae, Carabidae and Tineidae ) are present in many Australian guano communities. Several potential mechanisms of dispersal are discussed including phoresy, colonisation from soil, terrestrial migration and interstitial cavities. Endemism to specific caves cannot be definitely assigned to any species, although 13 species show restricted distribution.