The evolutionary success of beetles and numerous other terrestrial insects is generally attributed to co-radiation with flowering plants but most studies have focused on herbivorous or pollinating insects. Non-herbivores represent a significant proportion of beetle diversity yet potential factors that influence their diversification have been largely unexamined. In the present study, we examine the factors driving diversification within the Scarabaeidae, a speciose beetle family with a range of both herbivorous and non-herbivorous ecologies. In particular, it has been long debated whether the key event in the evolution of dung beetles (Scarabaeidae: Scarabaeinae) was an adaptation to feeding on dinosaur or mammalian dung. Here we present molecular evidence to show that the origin of dung beetles occurred in the middle of the Cretaceous, likely in association with dinosaur dung, but more surprisingly the timing is consistent with the rise of the angiosperms. We hypothesize that the switch in dinosaur diet to incorporate more nutritious and less fibrous angiosperm foliage provided a palatable dung source that ultimately created a new niche for diversification. Given the well-accepted mass extinction of non-avian dinosaurs at the Cretaceous-Paleogene boundary, we examine a potential co-extinction of dung beetles due to the loss of an important evolutionary resource, i.e., dinosaur dung. The biogeography of dung beetles is also examined to explore the previously proposed “out of Africa” hypothesis. Given the inferred age of Scarabaeinae as originating in the Lower Cretaceous, the major radiation of dung feeders prior to the Cenomanian, and the early divergence of both African and Gondwanan lineages, we hypothesise that that faunal exchange between Africa and Gondwanaland occurred during the earliest evolution of the Scarabaeinae. Therefore we propose that both Gondwanan vicariance and dispersal of African lineages is responsible for present day distribution of scarabaeine dung beetles and provide examples.

Under extreme (>80%) levels of habitat loss and fragmentation, exponentially increasing risks of extinction have been predicted; however, the proportion of species that will decline is uncertain. Factors influencing species declines include patch characteristics, such as size and condition, and species' ecological traits, such as dispersal ability. In central New South Wales, Australia, 90% of the mallee woodland has been cleared for agriculture. At each of three 100-km 2 locations, we sampled beetles in 10 sites and asked: (1) How is the impact of habitat loss and fragmentation mediated by remnant condition and size? (2) What proportion of the beetle fauna is declining? (3) Are ecological traits based on body size, trophic group, flight, and position relative to the ground correlated with beetle responses to habitat loss and fragmentation? Seven of 34 beetle species (21%) occurred in fragmented and isolated populations in the agricultural landscape, implying that they may be at risk of local extinction. Most declining species depended on large remnants, but two species were confined to disturbed linear remnants, emphasizing the importance of diverse management regimes for invertebrate conservation. In contrast, approximately one-quarter of the beetle fauna survived in paddocks and so was not at risk of decline. Greatest species richness was observed in narrow linear remnants, not square reserves, because of the influx of species from the matrix and the presence of strip-specialist species. Flying ability and position explained most of the variation in species responses to fragmentation. Flightless species or species living underground were most vulnerable to decline in agricultural landscapes. Combinations of traits were also implicated in beetle responses, however, suggesting that causal mechanisms involve more than just the effects of flight or position. To identify species vulnerable to decline in fragmented landscapes, then, many traits need to be considered simultaneously.Resumen: Bajo niveles extremos (>80%) de pérdida y fragmentación de hábitat, se han previsto riesgos de extinción que incrementan exponencialmente; sin embargo, la proporción de especies que declinarán es incierta. Los factores que influyen en la declinación de especies incluyen características del parche, como tamaño y condición, y los atributos ecológicos de las especies, como habilidad dispersora. En el centro de New South Wales, Australia, 90% del bosque se ha desmontado para agricultura. En cada una de tres localidades de 10 km 2 , muestreamos escarabajos en 10 sitios y preguntamos (1) ¿ ¿Cómo intervienen el tamaño y condición del remanente en el impacto de la pérdida de hábitat y fragmentación? (2) ¿Qué proporción de la fauna de §Current address: Beetle Responses to Habitat Fragmentation 183escarabajos esta declinando? (3) ¿Están correlacionados los atributos ecológicos basados en tamaño corporal, grupo trófico, suelo y posición en relación con el suelo con las respuestas de escarabajos a la pérdida y fragmentación de hábitat? Siete ...

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Climate fluctuations and tectonic reconfigurations associated with environmental changes play large roles in determining patterns of adaptation and diversification, but studies documenting how such drivers have shaped the evolutionary history and diversification dynamics of limnic organisms during the Mesozoic are scarce. Members of the heteropteran infraorder Nepomorpha, or aquatic bugs, are ideal for testing the effects of these determinants on their diversification pulses because most species are confined to aquatic environments during their entire life. The group has a relatively mature taxonomy and is well represented in the fossil record. We investigated the evolution of Nepomorpha based on phylogenetic analyses of morphological and molecular characters sampled from 115 taxa representing all 13 families and approximately 40% of recognized genera. Our results were largely congruent with the phylogenetic relationships inferred from morphology. A divergence dating analysis indicated that Nepomorpha began to diversify in the late Permian (approximately 263 Ma), and diversification analyses suggested that palaeoecological opportunities probably promoted lineage diversification in this group.

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Water striders and their allies (Hemiptera, Gerromorpha) are familiar inhabitants of water surfaces throughout the world. One of the most species-rich groups is the subfamily Microveliinae (Veliidae) and, in particular, the genus Microvelia Westwood, 1834. This genus comprises small or very small bugs inhabiting the nearshore areas of stagnant or slow-flowing fresh water. Accumulation of material during the past 30 years has shown that the Australian fauna of Microvelia is much richer and more diverse than previously recognised. In the present paper we discuss the subgeneric classification of the genus Microvelia based on the results of a phylogenetic analysis using maximum parsimony, describe three new subgenera and redescribe all previously known Australian species of the genus. The new taxa are: Microvelia (Austromicrovelia), subgen. nov. (type species: Microvelia mjobergi Hale, 1925) with the species Microvelia (Austromicrovelia) spurgeon, M. hypipamee, M. margaretae, M.�monteithi, M. tuberculata, M. myorensis, M. woodwardi, M. carnarvon, M. annemarieae, M. mossman, spp. nov. (all from Queensland), M. eborensis and M. milleri, spp. nov. (New South Wales), M. queenslandiae, M.�ventrospinosa, spp. nov. (New South Wales, Queensland), M. angelesi, M. alisonae, M. odontogaster, spp. nov. (Northern Territory), M. apunctata, sp. nov. (Northern Territory, Queensland), M. pennicilla, sp. nov. (Northern Territory, Western Australia), M. herberti, M. malipatili, M. torresiana, and M. australiensis, spp. nov. (Northern Territory, Queensland, Western Australia), Microvelia (Barbivelia), subgen. nov. (type species: Microvelia barbifer, sp. nov.) with the species Microvelia (Barbivelia) barbifer, sp. nov. (Queensland) and M. falcifer, sp. nov. (Northern Territory); Microvelia (Pacificovelia), subgen. nov. (type species: Microvelia oceanica Distant, 1914) with the species M. tasmaniensis, sp. nov. (Tasmania), M. lilliput, and M. kakadu, spp. nov. (Northern Territory, Queensland, Western Australia). We further recognise the subgenus Microvelia (Picaultia), stat. nov. (type species: Picaultia pronotalis Distant, 1913), and describe the following new species: Microvelia (Picaultia) justi and M. paramega, spp. nov. (Northern Territory, Queensland, Western Australia), and M. cassisi, sp. nov. (New South Wales). Finally, Microvelia fluvialis weiri Malipatil, 1980, is synonymised with Microvelia fluvialis Malipatil, 1980. Keys to adults of all species are provided and their distributions mapped.

The semiaquatic bugs (Hemiptera:Heteroptera, infraorder Gerromorpha), comprising water striders and their allies, are familiar inhabitants of water surfaces in all continents. Currently, the world fauna has more than 1900 described species classified in eight families and 165 genera. A phylogenetic analysis using maximum parsimony was performed on a dataset comprising 56 morphological characters scored for 24 exemplar genera covering all families and subfamilies of Gerromorpha. The phylogenetic relationships found concur with those presented by Andersen (1982) except that the relationships between some subfamilies of Veliidae and Gerridae are unresolved. The Australian fauna of Gerromorpha comprises six families, 30 genera, and 123 species. One-third of the genera and more than 80% of the species are endemic to Australia. Previously, we have covered all Australian species of the families Gerridae, Hermatobatidae and Veliidae. The present paper deals with the families Hebridae, Hydrometridae, and Mesoveliidae. We offer redescriptions or descriptive notes on all previously described species, describe Mesovelia ebbenielseni , sp. nov. (Mesoveliidae), Austrohebrus apterus , gen. et sp. nov., and Hebrus pilosus , sp. nov. (Hebridae), and synonymise Hebrus woodwardi Lansbury, syn. nov. (Hebridae) and Hydrometra halei Hungerford and Evans, syn. nov. (Hydrometridae). We present keys for the identification of genera and species, and map the distribution of all species. We also give a key for the identification of the families of Gerromorpha known from Australia.