Corymbia leaf oils, latitude, hybrids and herbivory: a test using common-garden field trials

Foliar oils, particularly monoterpenes, can influence the susceptibility of plants to herbivory. In plants, including eucalypts, monoterpenes are often associated with plant defence. A recent analysis revealed an increase in foliar oil content with increasing latitudinal endemism, and we tested this pattern using three eucalypt taxa comprising a latitudinal replacement cline. We also examined the relative concentrations of two monoterpenes (alpha-pinene and 1,8-cineole), for which meta-analyses also showed latitudinal variation, using hybrids of these three taxa with Corymbia torelliana. These, and pure C. torelliana, were then assessed in common-garden field plots for the abundance and distribution of herbivory by four distinct herbivore taxa. Differing feeding strategies among these herbivores allowed us to test hypotheses regarding heritability of susceptibility and relationships to alpha-pinene and 1,8-cineole. We found no support for an increase in foliar oil content with increasing latitude, nor did our analysis support predictions for consistent variation in alpha-pinene and 1,8-cineole contents with latitude. However, herbivore species showed differential responses to different taxa and monoterpene contents. For example, eriophyid mites, the most monophagous of our censused herbivores, avoided the pure species, but fed on hybrid taxa, supporting hypotheses on hybrid susceptibility. The most polyphagous herbivore (leaf blister sawfly Phylacteophaga froggatti) showed no evidence of response to plant secondary metabolites, while the distribution and abundance patterns of Paropsis atomaria showed some relationship to monoterpene yields.

Evaluation of rumen fatty acid hydrogenation intermediates and differences in bacterial communities after feeding wheat- or corn-based dried distillers grains to feedlot cattle

The effect of partially replacing rolled barley (86.6% of control diet) with 20% wheat dried distillers grains plus solubles (DDGS), 40% wheat DDGS, 20% corn DDGS, or 40% corn DDGS (dietary DM basis) on rumen fluid fatty acid (FA) composition and some rumen bacterial communities was evaluated using 100 steers (20 per treatment). Wheat DDGS increased the 11t-to 10t-18:1 ratio (P < 0.05) in rumen fluid and there was evidence that the conversion of trans-18:1 to 18:0 was reduced in the control and wheat DDGS diets but not in the corn DDGS diet. Bacterial community profiles obtained using denaturing gradient gel electrophoresis and evaluated by Pearson correlation similarity matrices were not consistent for diet and, therefore, these could not be linked to different specific rumen FA. This inconsistency may be related to the nature of diets fed (dominant effect of barley), limited change in dietary composition as the result of DDGS inclusion, large animal-to-animal variation, and possibly additional stress as a result of transport just before slaughter. Ruminal densities of a key fiber-digesting bacteria specie that produces 11t-18:1 from linoleic and linolenic acids (Butyrivibrio fibrisolvens), and a lactate producer originally thought responsible for production of 10t, 12c-18:2 (Megasphaera elsdenii) were not influenced by diet (P > 0.05).

Comparison of the reproductive ecology of two sympatric blacktip sharks (Carcharhinus limbatus and Carcharhinus tilstoni) off north-eastern Australia with species identification inferred from vertebral counts

Precaudal vertebral counts were used to distinguish between 237 morphologically similar Carcharhinus limbatus and Carcharhinus tilstoni and were congruent with differences in reproductive ecology between the species. In addition to differing lengths at maturity and adult body size, the two species had asynchronous parturition, were born at different sizes and the relative frequencies of neonates differed in two coastal nursery areas. Despite evidence that hybridization can occur, these differences suggest the species are largely reproductively isolated.

A review of the biology, ecology, distribution and control of Mozambique tilapia, Oreochromis mossambicus (Peters 1852) (Pisces: Cichlidae) with particular emphasis on invasive Australian populations

Oreochromis mossambicus (Peters 1852) are native to the eastward flowing rivers of central and southern Africa but from the early 1930s they have been widely distributed around the world for aquaculture and for biological control of weeds and insects. While O. mossambicus are now not commonly used as an aquaculture species, the biological traits that made them a popular culture species including tolerance to wide ranging ecological conditions, generalist dietary requirements and rapid reproduction with maternal care have also made them a 'model' invader. Self-sustaining populations now exist in almost every region to which they have been imported. In Australia, since their introduction in the 1970s, O. mossambicus have become established in catchments along the east and west coasts and have the potential to colonise other adjacent drainages. It is thought that intentional translocations are likely to be the most significant factor in their spread in Australia. The ecological and physical tolerances and preferences, reproductive behaviour, hybridization and the high degree of plasticity in the life history traits of O. mossambicus are reviewed. Impacts of O. mossambicus on natural ecosystems including competitive displacement of native species, habitat alteration, predation and as a vector in the spread of diseases are discussed. Potential methods for eradicating or controlling invasive populations of O. mossambicus including physical removal, piscicides, screens, environmental management and genetic technologies are outlined.

Australian spore-feeding thrips of the genus Phaulothrips (Thysanoptera, Idolothripinae)

Breeding by several of the spore-feeding species in the genus Phaulothrips is shown to be associated with abandoned tunnels of bees and scolytid beetles, as well as with the dead seed capsules of Eucalyptus species. The breeding sites for other species in the genus remain unknown, but 16 species are here recognised from Australia, of which the following six are newly described: P. daguilaris, P. flindersi, P. kingae, P. kranzae, P. oakeyi, P. whyallae. Copyright © 2013 Magnolia Press.

An overview on the role of Hexanchiformes in marine ecosystems: biology, ecology and conservation status of a primitive order of modern sharks

The large size, high trophic level and wide distribution of Hexanchiformes (cow and frilled sharks) should position this order as important apex predators in coastal and deep-water ecosystems. This review synthesizes available information on Hexanchiformes, including information not yet published, with the purpose of evaluating their conservation status and assessing their ecological roles in the dynamics of marine ecosystems. Comprising six species, this group has a wide global distribution, with members occurring from shallow coastal areas to depths of c. 2500 m. The limited information available on their reproductive biology suggests that they could be vulnerable to overexploitation (e.g. small litter sizes for most species and suspected long gestation periods). Most of the fishing pressure exerted on Hexanchiformes is in the form of commercial by-catch or recreational fishing. Comprehensive stock and impact assessments are unavailable for most species in most regions due to limited information on life history and catch and abundance time series. When hexanchiform species have been commercially harvested, however, they have been unable to sustain targeted fisheries for long periods. The potentially high vulnerability to intense fishing pressure warrants a conservative exploitation of this order until thorough quantitative assessments are conducted. At least some species have been shown to be significant apex predators in the systems they inhabit. Should Hexanchiformes be removed from coastal and deep-water systems, the lack of sympatric shark species that share the same resources suggests no other species would be capable of fulfilling their apex predator role in the short term. This has potential ecosystem consequences such as meso-predator release or trophic cascades. This review proposes some hypotheses on the ecology of Hexanchiformes and their role in ecosystem dynamics, highlighting the areas where critical information is required to stimulate research directions.

The importance of grasslands for animal production and other functions: a review on management and methodological progress in the tropics

The global importance of grasslands is indicated by their extent; they comprise some 26% of total land area and 80% of agriculturally productive land. The majority of grasslands are located in tropical developing countries where they are particularly important to the livelihoods of some one billion poor peoples. Grasslands clearly provide the feed base for grazing livestock and thus numerous high-quality foods, but such livestock also provide products such as fertilizer, transport, traction, fibre and leather. In addition, grasslands provide important services and roles including as water catchments, biodiversity reserves, for cultural and recreational needs, and potentially a carbon sink to alleviate greenhouse gas emissions. Inevitably, such functions may conflict with management for production of livestock products. Much of the increasing global demand for meat and milk, particularly from developing countries, will have to be supplied from grassland ecosystems, and this will provide difficult challenges. Increased production of meat and milk generally requires increased intake of metabolizable energy, and thus increased voluntary intake and/or digestibility of diets selected by grazing animals. These will require more widespread and effective application of improved management. Strategies to improve productivity include fertilizer application, grazing management, greater use of crop by-products, legumes and supplements and manipulation of stocking rate and herbage allowance. However, it is often difficult to predict the efficiency and cost-effectiveness of such strategies, particularly in tropical developing country production systems. Evaluation and on-going adjustment of grazing systems require appropriate and reliable assessment criteria, but these are often lacking. A number of emerging technologies may contribute to timely low-cost acquisition of quantitative information to better understand the soil-pasture-animal interactions and animal management in grassland systems. Development of remote imaging of vegetation, global positioning technology, improved diet markers, near IR spectroscopy and modelling provide improved tools for knowledge-based decisions on the productivity constraints of grazing animals. Individual electronic identification of animals offers opportunities for precision management on an individual animal basis for improved productivity. Improved outcomes in the form of livestock products, services and/or other outcomes from grasslands should be possible, but clearly a diversity of solutions are needed for the vast range of environments and social circumstances of global grasslands.

Dingoes at the doorstep: Preliminary data on the ecology of dingoes in urban areas

Wild carnivores are becoming increasing common in urban areas. In Australia, dingoes exist, in most large cities and towns within their extended range. However, little empirical data is available to inform dingo management or address potential dingo–human conflicts during urban planning. From GPS tracking data, the nine dingoes, predominately juvenile and female, we tracked lived within 700 m of residential homes at all times and frequently crossed roads, visited backyards and traversed built-up areas. Home range sizes ranged between 0.37 km2 and 100.32 km2. Dingoes were mostly nocturnal, averaging 591 m/h between dusk and dawn. Juvenile and adult dingoes spent up to 19% and 72% of their time in urban habitats. Fresh scats from most areas surveyed tested positive to a variety of common zoonoses. These data suggest dingoes are capable of exploiting peri-urban areas and might contribute to human health and safety risks, the significance of which remains unknown.

Localization of feeding of Anomalococcus indicus (Hemiptera: Lecanodiaspididae) and supplementary biological notes: Towards the biological management of the invasive tree Vachellia nilotica indica (Fabales: Mimosoideae) in North-Eastern Australia

. Management of the invasive Vachellia nilotica indica infesting tropical grasslands of Northern Australia has remained unsuccessful to date. Presently Anomalococcus indicus is considered a potential agent in the biological management of V. n. indica. Whereas generic biological details of A. indicus have been known, their feeding activity and details of their mouthparts and the sensory structures that are associated with their feeding action are not known. This paper provides details of those gaps. Nymphal instars I and II feed on cortical-parenchyma cells of young stems of V. n. indica, whereas nymphal instars III and adult females feed on phloem elements of older shoots. Nymphal instars and adults (females) trigger stress symptoms in the feeding tissue with cells bearing enlarged and disfigured nuclei, cytoplasmic shrinkage, cytoplasmic trabeculae, abnormal protuberances and uneven cell wall thickening, unusual cell membrane proliferation, and exhausted and necrosed cells. Continuous nutrient extraction by A. indicus can cause stem death. We provide evidence that A. indicus, by virtue of its continuous feeding activity and intense population build up, can be an effective biological-management agent to regulate populations of V. n. indica in infested areas. © 2014 © 2014 Société entomologique de France.

A new gall midge of the genus Dentifibula (Diptera: Cecidomyiidae), a predator of the scale insect Aulacaspis australis feeding on mangrove Bruguiera gymnorrhiza

Dentifibula nigroapicalisKolesik sp. nov., a new species of gall midge, is described whose larvae were found preying on the mangrove scale insect Aulacaspis australisBrimblecombe (Hemiptera: Coccoidea: Diaspididae). The mangrove scale was feeding on leaves of the mangrove Bruguiera gymnorrhiza (Rhizophoraceae) in Queensland. The new species is the first DentifibulaFelt known from Australia. © 2013 Australian Entomological Society.

Fungus-feeding thrips from Australia in the worldwide genus Hoplandrothrips (Thysanoptera, Phlaeothripinae)

From Australia, 16 species of Hoplandrothrips are here recorded, of which 11 are newly described. An illustrated key is provided to 15 species, but Phloeothrips leai Karny cannot at present be recognised from its description. The generic relationships between Hoplandrothrips, Hoplothrips and some other Phlaeothripinae that live on freshly dead branches are briefly discussed.

Rhipicephalus (Boophilus) microplus tick in vitro feeding methods for functional (dsRNA) and vaccine candidate (antibody) screening

Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) ticks cause economic losses for cattle industries throughout tropical and subtropical regions of the world estimated at $US2.5 billion annually. Lack of access to efficacious long-lasting vaccination regimes and increases in tick acaricide resistance have led to the investigation of targets for the development of novel tick vaccines and treatments. In vitro tick feeding has been used for many tick species to study the effect of new acaricides on the transmission of tick-borne pathogens. Few studies have reported the use of in vitro feeding for functional genomic studies using RNA interference and/or the effect of specific anti-tick antibodies. In particular, in vitro feeding reports for the cattle tick are limited due to its relatively short hypostome. Previously published methods were further modified to broaden optimal tick sizes/weights, feeding sources including bovine and ovine serum, optimisation of commercially available blood anti-coagulant tubes, and IgG concentrations for effective antibody delivery. Ticks are fed overnight and monitored for ∼5–6 weeks to determine egg output and success of larval emergence using a humidified incubator. Lithium-heparin blood tubes provided the most reliable anti-coagulant for bovine blood feeding compared with commercial citrated (CPDA) and EDTA tubes. Although >30 mg semi-engorged ticks fed more reliably, ticks as small as 15 mg also fed to repletion to lay viable eggs. Ticks which gained less than ∼10 mg during in vitro feeding typically did not lay eggs. One mg/ml IgG from Bm86-vaccinated cattle produced a potent anti-tick effect in vitro (83% efficacy) similar to that observed in vivo. Alternatively, feeding of dsRNA targeting Bm86 did not demonstrate anti-tick effects (11% efficacy) compared with the potent effects of ubiquitin dsRNA. This study optimises R. microplus tick in vitro feeding methods which support the development of cattle tick vaccines and treatments.