Preference and performance of Aconophora compressa Walker (Hemiptera: Membracidae) on different lantana phenotypes in Australia

The plant phenotypic preference and performance of Aconophora compressa, a biocontrol agent for Lantana camara in Australia, were assessed. Overall, there were no significant trends of A. compressa favouring any one particular phenotype. However, there was a gradual decrease in performance through subsequent generations, with populations of A. compressa dying out on two phenotypes. Females did not show preference for any particular lantana phenotype, ovipositing similarly on all five phenotypes presented in choice trials and all 16 phenotypes in no-choice trials. Nymphs developed on all 16 phenotypes tested. Percent development and time to complete development were not significant in the first generation but were significant in the second generation. There was a general decrease in performance with generation. However, this was probably due to rising temperatures with season rather than an effect of phenotype. These results suggest that A. compressa should establish on all phenotypes within its geographic range.

Native and exotic pests of Eucalyptus: A worldwide perspective.

Eucalyptus species, native to Australia, Indonesia, the Philippines, and New Guinea, are the most widely planted hardwood timber species in the world. The trees, moved around the globe as seeds, escaped the diverse community of herbivores found in their native range. However, a number of herbivore species from the native range of eucalypts have invaded many Eucalyptus-growing regions in North America, Europe, Africa, Asia, and South America in the last 30 years. In addition, there have been shifts of native species, particularly in Africa, Asia, and South America, onto Eucalyptus. There are risks that these species as well as generalist herbivores from other parts of the world will invade Australia and threaten the trees in their native range. The risk to Eucalyptus plantations in Australia is further compounded by planting commercially important species outside their endemic range and shifting of local herbivore populations onto new host trees. Understanding the mechanisms underlying host specificity of Australian insects can provide insight into patterns of host range expansion of both native and exotic insects.

Characterization of the mitochondrial active-site serine protein LACTB: filaments in the mitochondrial intermembrane space

Mitochondria have evolved from endosymbiotic alpha-proteobacteria. During the endosymbiotic process early eukaryotes dumped the major component of the bacterial cell wall, the peptidoglycan layer. Peptidoglycan is synthesized and maintained by active-site serine enzymes belonging to the penicillin-binding protein and the β-lactamase superfamily. Mammals harbor a protein named LACTB that shares sequence similarity with bacterial penicillin-binding proteins and β-lactamases. Since eukaryotes lack the synthesis machinery for peptidoglycan, the physiological role of LACTB is intriguing. Recently, LACTB has been validated in vivo to be causative for obesity, suggesting that LACTB is implicated in metabolic processes. The aim of this study was to investigate the phylogeny, structure, biochemistry and cell biology of LACTB in order to elucidate its physiological function. Phylogenetic analysis revealed that LACTB has evolved from penicillin binding-proteins present in the bacterial periplasmic space. A structural model of LACTB indicates that LACTB shares characteristic features common to all penicillin-binding proteins and β-lactamases. Recombinat LACTB protein expressed in E. coli was recovered in significant quantities. Biochemical and cell biology studies showed that LACTB is a soluble protein localized in the mitochondrial intermembrane space. Further analysis showed that LACTB preprotein underwent proteolytic processing disclosing an N-terminal tetrapeptide motif also found in a set of cell death-inducing proteins. Electron microscopy structural studies revealed that LACTB can polymerize to form stable filaments with lengths ranging from twenty to several hundred nanometers. These data suggest that LACTB filaments define a distinct microdomain in the intermembrane space. A possible role of LACTB filaments is proposed in the intramitochondrial membrane organization and microcompartmentation. The implications of these findings offer novel insight into the evolution of mitochondria. Further studies of the LACTB function might provide a tool to treat mitochondria-related metabolic diseases.

IXth International Symposium on Thysanoptera and Tospoviruses, 31st August-4th September 2009, Sea World Resort, Queensland, Australia.

This proceedings contains abstracts of 108 papers focusing on the different Tospovirus diseases of various crops and their thysanopteran vectors. The genetics of these pests and pathogens, the different methods used in their control and their geographical distribution are also highlighted.

Subtropical Banana Information Kit. Agrilink, your growing guide to better farming guide

Each Agrilink kit has been designed to be both comprehensive and practical. As the kits are arranged to answer questions of increasing complexity, they are useful references for both new and experienced producers of specific crops. Agrilink integrates the technology of horticultural production with the management of horticultural enterprises. REPRINT INFORMATION - PLEASE READ! For updated information please call 13 25 23 or visit the website www.deedi.qld.gov.au (Select: Queensland Industries – Agriculture link) This publication has been reprinted as a digital book without any changes to the content published in 2004. We advise readers to take particular note of the areas most likely to be out-of-date and so requiring further research: see detailed information on first page of the kit. Even with these limitations we believe this information kit provides important and valuable information for intending and existing growers. This publication was last revised in 2004. The information is not current and the accuracy of the information cannot be guaranteed by the State of Queensland. This information has been made available to assist users to identify issues involved in the production of subtropical bananas. This information is not to be used or relied upon by users for any purpose which may expose the user or any other person to loss or damage. Users should conduct their own inquiries and rely on their own independent professional advice. While every care has been taken in preparing this publication, the State of Queensland accepts no responsibility for decisions or actions taken as a result of any data, information, statement or advice, expressed or implied, contained in this publication.

Effect of constant temperature on the development of Sceliodes cordalis (Doubleday) (Lepidoptera: Crambidae) on eggplant.

Abstract Sceliodes cordalis, eggfruit caterpillar, is an important pest of eggplant in Australia but little information was available on its biology. This study was conducted to determine the effect of temperature on the development on eggplant of eggs, larvae and pupae. Insects were reared at five constant temperatures from 20.5°C to 30.5°C with a 12:12 L : D photoperiod and the thermal summation model was fitted to the developmental rate data. Developmental zeroes and thermal constants of 11.22°C and 61.32 day-degrees for eggs, 12.03°C and 179.60 day-degrees for larvae, and 14.43°C and 107.03 day-degrees for pupae were determined. Several larvae reared at 20.5°C entered diapause.

Healthy hardwoods. A field guide to pests, diseases and nutritional disorders in subtropical hardwoods.

Healthy hardwoods: A field guide to pests, diseases and nutritional disorders in subtropical hardwoods can be used to help identify the common damaging insects, fungi and nutritional disorders in young eucalypt (Eucalyptus and Corymbia species) plantations in subtropical eastern Australia. This guide includes photographs of each insect, fungus and nutritional disorder and the damage they cause, along with a brief description to aid identification. A brief host list for insects and fungi, including susceptibility and occurrence, is provided as a guide only. A hand lens will be useful, especially to identify fungi. Although it is possible to identify insects and fungi from these photographs, laboratory examination will sometimes be necessary. For example, microscopes and culturing media might be used to identify fungi. Information about four exotic pests and diseases has also been included in the Biosecurity threats chapter. Potentially, these would have a severe impact on plantation and natural forests if introduced into Australia. To prevent establishment of these pests, early detection and identification is crucial. If an exotic insect or disease is suspected, then an immediate response is required. Usually, the first response will be to contact the nearest Australian Quarantine and Inspection Service office or forestry agency to seek advice.

The Mechanisms of Hedgehog Signal Transduction

Studies in both vertebrates and invertebrates have identified proteins of the Hedgehog (Hh) family of secreted signaling molecules as key organizers of tissue patterning. Initially discovered in Drosophila in 1992, Hh family members have been discovered in animals with body plans as diverse as those of mammals, insects and echinoderms. In humans three related Hh genes have been identified: Sonic, Indian and Desert hedgehog (Shh, Ihh and Dhh). Transduction of the Hh signal to the cytoplasm utilizes an unusual mechanism involving consecutive repressive interactions between Hh and its receptor components, Patched (Ptc) and Smoothened (Smo). Several cytoplasmic proteins involved in Hh signal transduction are known in Drosophila, but mammalian homologs are known only for the Cubitus interruptus (Ci) transcription factor (GLI(1-3)) and for the Ci/GLI-associated protein, Suppressor of Fused (Su(fu)). In this study I analyzed the mechanisms of how the Hh receptor Ptc regulates the signal transducer Smo, and how Smo relays the Shh signal from the cell surface to the cytoplasm ultimately leading to the activation of GLI transcription factors. In Drosophila, the kinesin-like protein Costal2 (Cos2) is required for suppression of Hh target gene expression in the absence of ligand, and loss of Cos2 causes embryonic lethality. Cos2 acts by bridging Smo to the Ci. Another protein, Su(Fu) exerts a weak suppressive influence on Ci activity and loss of Su(Fu) causes subtle changes in Drosophila wing pattern. This study revealed that domains in Smo that are critical for Cos2 binding in Drosophila are dispensable for mammalian Smo function. Furthermore, by analyzing the function of Su(Fu) and the closest mouse homologs of Cos2 by protein overexpression and RNA interference I found that inhibition of the Hh response pathway in the absence of ligand does not require Cos2 activity, but instead critically depends on the activity of Su(Fu). These results indicate that a major change in the mechanism of action of a conserved signaling pathway occurred during evolution, probably through phenotypic drift made possible by the existence in some species of two parallel pathways acting between the Hh receptor and the Ci/GLI transcription factors. In a second approach to unravel Hh signaling we cloned > 90% of all human full-length protein kinase cDNAs and constructed the corresponding kinase-activity deficient mutants. Using this kinome resource as a screening tool, two kinases, MAP3K10 and DYRK2 were found to regulate Shh signaling. DYRK2 directly phosphorylated and induced the proteasome dependent degradation of the key Hh-pathway regulated transcription factor, GLI2. MAP3K10, in turn, affected GLI2 indirectly by modulating the activity of DYRK2.

Probiotic activity of Lactobacillus delbrueckii subsp. bulgaricus in the oral cavity

Yogurt consumption has been related to longevity of some populations living on the Balkans. Yogurt starter L. delbrueckii subsp. bulgaricus and Str. thermophilus have been recognized as probiotics with verified beneficial health effects. The oral cavity emerges as a arget for probiotic applications. Probiotics have demonstrated promising results in controlling dental diseases and oral yeast infections. However, L. bulgaricus despite its broad availability in dairy products has not been evaluated for probiotic activity in the mouth. These series of studies investigated in vitro properties of L. bulgaricus to outline its potential as an oral probiotic. Prerequisite probiotic properties in the mouth are resistance to oral defense mechanisms, adherence to saliva-coated surfaces, and inhibition of oral pathogens. L. bulgaricus strains showed a strain-dependent inhibition of oral streptococci and Aggregatibacter actinomycetemcomitans, whereas none of the dairy starter strains could affect growth of Porphyromonas gingivalis and Fusobacterium nucleatum. Adhesion is a factor contributing to colonization of the species at the target site. Radiolabeled L. bulgaricus strains and L. rhamnosus GG were tested for their ability to adhere to saliva-coated surfaces. The effects of lysozyme on adhesion and adhesion of Streptococcus sanguinis after lactobacilli pretreatment were also assessed. Adhesion of L. bulgaricus remained lower in comparison to L. rhamnosus GG. One L. bulgaricus strain showed binding frequency comparable to S. sanguinis. Lysozyme pretreatment significantly increased Lactobacillus adhesion. Low gelatinolytic activity was observed for all strains and no conversion of proMMP-9 to its active form was induced by L. bulgaricus. Safety assessment ruled out deleterious effects of L. bulgaricus on extracellular matrix structures. Cytokine response of oral epithelial cells was assessed by measuring IL-8 and TNF-α in cell culture supernatants. The effect of P. gingivalis on cytokine secretion after lactobacilli pretreatment was also assessed. A strain- and time-dependent induction of IL-8 was observed with live bacteria inducing the highest levels of cytokine secretion. Levels of TNF-α were low and only one of ten L. bulgaricus strains stimulated TNF-α secretion similar to positive control. The addition of P. gingivalis produced immediate reduction of cytokine levels within the first hours of incubation irrespective of lactobacilli strains co-cultured with epithelial cells. According to these studies strains among the L. delbrueckii subsp. bulgaricus species may have beneficial probiotic properties in the mouth. Their potential in prevention and management of common oral infectious diseases needs to be further studied.

Preliminary investigation into the induction of reproduction in Ulva spp. in Southeast Queensland for mass cultivation purposes

Ulva is a common component of marine intertidal flora in Australia with many species frequently observed along the Queensland coastline. Three species of Ulva, U. lactuca, U. intestinalis and U. prolifera were found to naturally occur at the Bribie Island Research Centre (BIRC) in Southeast Queensland. Studies were undertaken to establish the most optimal conditions for growing Ulva in the BIRC laboratory. These tests were conducted in order to condition the algal material prior to the sporulation studies, offering more controlled material to assess treatment effects conclusively, and helping eliminate other potentially confounding environmental factors. Results showed that a stocking density of between 5-20 grams of Ulva per litre along with the addition of the soluble fertiliser Aquasol at a rate of 87 mg/L of seawater was ideal for achieving a desired doubling of growth per week. In the wild the formation of Ulva fragments occurs naturally in the ocean through wave and storm action. This breakage can trigger a survival response mechanism which stimulates the algae to form and release gametes. By chopping the tissue, this process could be artificially simulated in the laboratory and creating a simple and easy way to produce new individuals. Studies performed into inducing sporulation in Ulva through a combination of fragmentation and renewal of medium at BIRC showed that sporulation can be successfully induced in all three species of Ulva through these methods, however it was found to be to a degree that would not meet the demands of commercial production with on average a rate of only 33% achieved. While the current study did not find a method suitable for a commercial application the results presented here contribute to increasing our understanding about Ulva reproduction and set a platform for future work in to cultivating Ulva within Southeast Queensland.

The spatiotemporal dynamics of Tribolium castaneum (Herbst): adult flight and gene flow.

Tribolium castaneum (Herbst) has been used as a model organism to develop and test important ecological and evolutionary concepts and is also a major pest of grain and grain products globally. This beetle species is assumed to be a good colonizer of grain storages through anthropogenic movement of grain, and active dispersal by flight is considered unlikely. Studies using T. castaneum have therefore used confined or walking insects. We combine an ecological study of dispersal with an analysis of gene flow using microsatellites to investigate the spatiotemporal dynamics and adult flight of T. castaneum in an ecological landscape in eastern Australia. Flying beetles were caught in traps at grain storages and in fields at least 1 km from the nearest stored grain at regular intervals for an entire year. Significantly more beetles were trapped at storages than in fields, and almost no beetles were caught in native vegetation reserves many kilometres from the nearest stored grain. Genetic differentiation between beetles caught at storages and in fields was low, indicating that although T. castaneum is predominantly aggregated around grain storages, active dispersal takes place to the extent that significant gene flow occurs between them, mitigating founder effects and genetic drift. By combining ecological and molecular techniques, we reveal much higher levels of active dispersal through adult flight in T. castaneum than previously thought. We conclude that the implications of adult flight to previous and future studies on this model organism warrant consideration.

The function of Bmps and Runx2 in normal tooth development and in the pathogenesis of cleidocranial dysplasia

The development of many embryonic organs is regulated by reciprocal and sequential epithelial-mesenchymal interactions. These interactions are mediated by conserved signaling pathways that are reiteratively used. Cleidocranial dysplasia (CCD) is a congenital syndrome where both bone and tooth development is affected. The syndrome is characterized by short stature, abnormal clavicles, general bone dysplasia, and supernumerary teeth. CCD is caused by mutations in RUNX2, a transcription factor that is a key regulator of osteoblast differentiation and bone formation. The first aim of this study was to analyse the expression of a family of key signal molecules, Bone morphogenetic protein (Bmp) at different stages of tooth development. Bmps have a variety of functions and they were originally discovered as signals inducing ectopic bone formation. We performed a comparative in situ hybridisation analysis of the mRNA expression of Bmp2-7 from initiation of tooth development to differentiation of dental hard tissues. The expression patterns indicated that the Bmps signal between the epithelial and mesenchymal tissues during initiation and morphogenesis of tooth development, as well as during the differentiation of odontoblasts and ameloblasts. Furthermore, they are also part of the signalling networks whereby the enamel knot regulates the patterning of tooth cusps. The second aim was to study the role of Runx2 during tooth development and thereby to gain better understanding of the pathogenesis of the tooth phenotype in CCD. We analysed the tooth phenotype of Runx2 knockout mice and examined the patterns and regulation of Runx2 gene expression.. The teeth of wild-type and Runx2 mutant mice were compared by several methods including in situ hybridisation, tissue culture, bead implantation experiments, and epithelial-mesenchymal recombination studies. Phenotypic analysis of Runx2 -/- mutant tooth development showed that teeth failed to advance beyond the bud stage. Runx2 expression was restricted to dental mesenchyme between the bud and early bell stages of tooth development and it was regulated by epithelial signals, in particular Fgfs. We searched for downstream targets of Runx2 by comparative in situ hybridisation analysis. The expression of Fgf3 was downregulated in the mesenchyme of Runx2 -/- teeth. Shh expression was absent from the enamel knot in the lower molars of Runx2 -/- and reduced in the upper molars. In conclusion, these studies showed that Runx2 regulates key epithelial-mesenchymal interactions that control advancing tooth morphogenesis and histodifferentiation of the epithelial enamel organ. In addition, in the upper molars of Runx2 mutants extra buddings occured at the palatal side of the tooth bud. We suggest that Runx2 acts as an inhibitor of successional tooth formation by preventing advancing development of the buds. Accordingly, we propose that RUNX2 haploinsuffiency in humans causes incomplete inhibition of successional tooth formation and as a result supernumerary teeth.

Optimise efficacy of broiler house treatments for the management of lesser mealworm

The Australian chicken meat industry requires effective agents for the management of lesser mealworm in broiler houses. The only two appropriate insecticides currently registered are cyfluthrin and spinosad, with gamma cyhalothrin being developed for registration. The industry requires the efficacy of cyfluthrin to be investigated, with progress and adoption of the latter two chemicals. Optimising the efficacy of each chemical and studying them singly and in rotation will, in addition to improving their efficacy, reduce overall insecticide use and improve their cost effectiveness.

Monitoring darkling beetle populations for resistance to spinosad

Management of insecticide resistance.

Trialling Biological Agents for the Management of Lesser Mealworm in Australian Broiler Houses

For approximately three decades the Australian broiler industry has relied heavily on the use of insecticides as its key tool for management of darkling beetle or lesser mealworm, Alphitobius diaperinus [Panzer] in broiler houses. The use of these chemicals over this period has been largely unchecked which has resulted in the development of strong insecticide resistance in many beetle populations from broiler farms. Although we are in a period now with an improved knowledge of managing resistance and the availability of new more effective insecticides that are currently marketed, the industry still requires more pest management options in order to inhibit development of resistance and reduce overall chemical use. In response to this need, ‘natural’ agents such as entomopathogenic nematodes and fungi were proposed as potential agents for managing darkling beetle populations in Australian broiler houses. Since 2007 laboratory and field studies have been undertaken to assess these agents. This report outlines these studies and discusses potential benefits to the Chicken Meat industry resulting from this research.