Quaternary beetles : a review and issues for Australian studies

Few Australian entomologists, ecologists, biogeographers or Quaternary researchers are familiar with the details of Quaternary beetle research. Since the 1950s the study of fossil beetles has developed to become an important discipline of the Quaternary sciences. Unfortunately, however, the significance of the discipline for ecological and evolutionary research has been slow to penetrate mainstream entomological, ecological, and evolutionary thought. This paper outlines the history, methods and results of Quaternary beetle studies, based primarily upon research from the well-studied Northern Hemisphere, and then examines issues relevant to Australian research. Analysis of Quaternary beetle assemblages from Australia can contribute to the reconstruction of past environments and climates, in particular quantitative estimation of past temperature regimes, and potentially, effective precipitation. Of more significance to entomology, however, is the potential to reconstruct climatically-induced changes in distribution, essential for understanding the Quaternary biogeographic history of Australia's insect fauna. Furthermore, it will be possible to examine evidence, or the lack thereof, for speciation during the Quaternary, in the context of Quaternary environmental change.

The mode of pheromone evolution: evidence from bark beetles

Sex and aggregation pheromones consist of species-specific blends of chemicals. The way in which different species’ blends have evolved has been the subject of some debate. Theoretical predictions suggest that differences between species have arisen not through the accruing of small changes, but through major shifts in chemical composition. Using data on the aggregation pheromones of 34 species of bark beetle from two genera, Dendroctonus and Ips, we investigated how the distributions of the chemical components of their pheromone blends mirror their phylogenetic relationships. We tested whether there were consistent patterns that could be used to help elucidate the mode of pheromone evolution. Although there were obvious differences in pheromone blends between the two genera, the differences between species within each genus followed a less clear phylogenetic pattern. In both genera, closely related species are just as different as more distantly related species. Within Dendroctonus, particularly, most chemical components were distributed randomly across the phylogeny. Indeed, for some chemicals, closely related species may actually be more different than would be expected from a random distribution of chemical components. This argues strongly against the idea of minor shifts in pheromone evolution. Instead, we suggest that, within certain phylogenetic constraints, pheromone evolution in bark beetles is characterized by large saltational shifts, resulting in sibling species being substantially phenotypically (i.e. pheromonally) different from one another, thus agreeing with theoretical predictions.

Species overlap, speciation and the evolution of aggregation pheromones in bark beetles

Theoretical predictions suggest that species-specific signals used in the attraction of mates should evolve to reduce the risk of mismating and hybridization. These predictions lead to the hypothesis that the signals of spatially overlapping (i.e. sympatric or syntopic) species should differ more substantially than those of non-overlapping species. Earlier studies have tested this prediction for auditory and visual signals. Here we test the hypothesis using olfactory signals, specifically the aggregation pheromones of species from two genera of bark beetles, Dendroctonus and Ips. We found no direct evidence from within these genera regarding the fact that the chemical blends that make up these pheromones differ more substantially in species that overlap in their geographical ranges and/or host-tree use than in allopatric taxa. However, when comparing between genera, the pheromones of overlapping species appear to be more similar than non-overlapping species. We hypothesize that the species of host tree utilized by the beetles may have some influence on their pheromone blends. Additionally, within genera, species that overlap in host use tend to be more closely related than species that use different hosts. These results may provide indirect evidence for an effect of species overlap on the evolution of bark beetle pheromones.

Plantations, not farmlands, cause biotic homogenisation of ground-active beetles in South-Eastern Australia

Following landscape change, species invasions and extinctions may lead to biotic homogenisation, resulting in increased taxonomic and functional similarity between previously distinct biotas. Biotic homogenisation is more likely to occur in landscapes where the matrix contrasts strongly with native vegetation patches. To test this, we examined the distribution of ground-active beetles in a landscape of remnant Eucalyptus open woodland patches where large areas of lower contrast matrix (farmland) are being transformed to high-contrast pine plantations in south-eastern Australia. We sampled beetles from 30 sites including six replicates of five categories; (1) remnants adjacent to farmland, (2) remnants adjacent to plantation, (3) farmland, (4) plantation, and, (5) remnants between pine plantation and farmland. Community composition in the pine matrix was similar to native patches embedded in pine (ANOSIM, Global R=. 0.49, P<. 0.000), which we suggest is due to biotic homogenisation. Remnant patches with edges of both farmland and pine plantation did not represent an intermediate community composition between patches surrounded by either matrix type, but rather a unique habitat with unique species. Farmland supported the greatest number of individuals (. F=. 9.049, df. =. 25, P<. 0.000) and species (. F=. 5.875, df. =. 25, P=. 0.002), even compared to native remnant patches. Our results suggest that matrix transformations can reduce species richness and homogenise within-patch populations. This may increase the risk of species declines in fragmented landscapes where plantations are not only replacing native vegetation patches, but also other matrix types that may better support biodiversity. Our findings are particularly concerning given expanding plantation establishment worldwide.

Unveiling the diversification dynamics of Australasian predaceous diving beetles in the Cenozoic

During the Cenozoic, Australia experienced major climatic shifts that have had dramatic ecological consequences for the modern biota. Mesic tropical ecosystems were progressively restricted to the coasts and replaced by arid-adapted floral and faunal communities. Whilst the role of aridification has been investigated in a wide range of terrestrial lineages, the response of freshwater clades remains poorly investigated. To gain insights into the diversification processes underlying a freshwater radiation, we studied the evolutionary history of the Australasian predaceous diving beetles of the tribe Hydroporini (147 described species). We used an integrative approach including the latest methods in phylogenetics, divergence time estimation, ancestral character state reconstruction, and likelihood-based methods of diversification rate estimation. Phylogenies and dating analyses were reconstructed with molecular data from seven genes (mitochondrial and nuclear) for 117 species (plus 12 outgroups). Robust and well-resolved phylogenies indicate a late Oligocene origin of Australasian Hydroporini. Biogeographic analyses suggest an origin in the East Coast region of Australia, and a dynamic biogeographic scenario implying dispersal events. The group successfully colonized the tropical coastal regions carved by a rampant desertification, and also colonized groundwater ecosystems in Central Australia. Diversification rate analyses suggest that the ongoing aridification of Australia initiated in the Miocene contributed to a major wave of extinctions since the late Pliocene probably attributable to an increasing aridity, range contractions and seasonally disruptions resulting from Quaternary climatic changes. When comparing subterranean and epigean genera, our results show that contrasting mechanisms drove their diversification and therefore current diversity pattern. The Australasian Hydroporini radiation reflects a combination of processes that promoted both diversification, resulting from new ecological opportunities driven by initial aridification, and a subsequent loss of mesic adapted diversity due to increasing aridity.

Are only the strong surviving? Little influence of restoration on beetles (Coleoptera) in an agricultural landscape

Habitat restoration has become an important part of biodiversity conservation in the face of extensive habitat loss and fragmentation, especially in agricultural landscapes. Study of invertebrates such as beetles (Coleoptera) may be important to assess the effectiveness of restoration techniques in maintaining native fauna, because they provide a variety of trophic roles and ecosystem services. In this study we examined the conservation value for beetles of revegetation in linear strips and alongside remnant patches compared with remnant vegetation and cleared roadsides. We also assessed how habitat variables structured beetle community composition. Beetle species richness and abundance did not substantially differ between revegetated, remnant and cleared areas, and was not substantially influenced by vegetation type and structure. Herbivorous beetles and the family Curculionidae were more species rich in cleared linear strips. Beetle fauna in these agricultural landscapes may be a robust subset of the pre-clearing beetle community, possibly due to the widespread degradation of remnant areas and the ground layer habitats within them. One beetle species had slightly higher abundance in remnant linear strips, suggesting that remnant habitats may be important for some beetle species. Importantly, environmental variables strongly influenced beetle community composition, signifying that beetle communities are still responding to factors such as soil type and native vegetation, rather than variables mainly associated with land management. The restoration practices currently being undertaken in agricultural areas may not maintain beetle species that require specific habitat variables to survive. Ground-layer attributes need to be included in future revegetation projects, and translocation of specialist species of beetles may be required to restore communities.

Marketing aboriginal art: an intellectual property fiction?

This paper argues that legality is not enough in seeking to solve the problems caused by charlatans and carpet baggers in the Australian Aboriginal art market. It examines the role of social marketing initially posited for the health sector and seeks to apply its strategies to the Aboriginal art market. The author draws comparisons between successes in health and the need for successes in the Aboriginal art market. It suggests that social marketing has been overlooked as a way forward for the Aboriginal art market. The paper concludes by stating that conditions will not change with quick-fix legal solutions sought for complex problems. They are an intellectual property fiction.

Vibrant, oppositional culture : the media and Australian political culture, 1880-1910

The notion that Australia has an entrenched “utilitarian political culture” has predominated in representations of political life and political culture in this country. Ostensibly, political life has been characterised above all by materialism and pragmatism, largely devoid of meaningful debate over ideas. There has, however, been a growing recognition that Australian political culture has been richer, more complex and less settled than commonly believed.

This paper examines the experience in late nineteenth and early twentieth century Australia, focussing on the role of the media in tandem with a burgeoning reading public as integral elements of a vibrant oppositional culture. Here, a passion for knowledge and self-improvement combined with a strong sense that cultivation of the mind was intrinsic to goals of moral, political and social development existed. The print media was centrally important in catering to and stimulating the interests, outlooks and aspirations of a diverse community of readers. Radical papers and journals jostled for attention alongside the mainstream press, supported by a spreading carpet of Mechanics Institutes and Schools of Arts, bookshops stocking a vast array of titles, and a comparatively large and increasingly professionalised literary-artistic intelligentsia.

Many different publics were being engaged and indeed constituted, from the very pragmatic to the strongly idealistic; from anarchists through to conservatives; from the strongly nationalistic through to those deeply loyal to God and Empire. Moreover, potentially quite complex patterns of understanding and attachment were being stimulated during this time. Taking clearer account of the media’s contribution to intellectual and literary pursuits during this period increases our understanding of the diverse and often contradictory traditions that have been part of Australian political culture.

Hope

In his second documentary on the trials of refugees to Australia, Steve Thomas tells the story of a maritime tragedy in October 2001. Amal Basry, (Amal means Hope) an Iraqi passenger on a people smuggling boat called Siev X destined for Australia, tells how it sank between Indonesia and Australia. Out of the 400 people crowded on the boat, 350 people drowned. As a survivor she fights to ensure that the disaster is not forgotten and to reunite her family. She tells of her terrible ordeal and her new life in Australia reunited with her husband and two sons.

The room that was

Wood, sensor, found office chair, DVD player and screen, spy-hole, carpet 1.9x2.5x7m. The ghost of a mad astormonk inhabits the space the viewer sits in. The Room That Was creates a new learning space for the improvement of the unco-operative body – a mobile mnemonia room. It is a place where the subject’s memory can be rendered to suit other points of view. The subject can be indoctrinated anytime, anywhere, and by any method inside the The Room That Was – especially designed for the dimensions of the average sized human body (astromonk – an incipient being). It is a mobile asylum for the European consciousness (much like Australia).

Predation of a small passerine by the Purple-winged Roller Coracias temminckii, an endemic species of Sulawesi

The usual diet of the Purple-winged Roller, a species endemic to Sulawesi, is grasshoppers, locusts, beetles and small lizards. This note describes an observation of this species preying on an adult Eurasian Tree Sparrow Passer montanus. The presence of birds in the diet of other roller species is discussed.

Effects of humidity on the response of the bark beetle Ips grandicollis (Eichhoff) (Coleoptera: Curculionidae: Scolytinae) to synthetic aggregation pheromone

Environmental factors may affect chemical communication between individuals by limiting their ability to detect and respond to these signals. One such factor, high humidity, has been shown to interfere with the normal response of some invertebrate species to their attractant pheromones. The effect of humidity on the response of the five-spined bark beetle, Ips grandicollis, to a synthetic form of the aggregation pheromone component ipsenol, was tested in an experimental chamber in the laboratory. The response was measured as both the number of beetles to reach the pheromone source and the time taken, and was tested under high (>80% relative humidity) and low (30–40% relative humidity) conditions of humidity. There was no significant difference in response of beetles between the two treatments although there was a reduction in response in the high-humidity treatment when relative humidity levels were in excess of 90%. These findings suggest that atmospheric humidity does not influence bark beetles response to synthetic pheromone, except perhaps in unlikely conditions of excessive humidity.