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Bellis G.A.,Northern Australia Quarantine Strategy | Gopurenko D.,Australian Department of Primary Industries and Fisheries | Gopurenko D.,Graham Center for Agricultural Innovation | Cookson B.,AAC International | And 5 more authors.
Austral Entomology | Year: 2015

Light trap surveillance across northern Australia and Papua New Guinea (PNG) has detected the presence of several Oriental species of Culicoides not previously reported from those countries and which appear to have arrived in recent times. Detections of C.nudipalpisDelfinado in Western Australia, C.flavipunctatusKitaoka and C.palpiferDas Gupta and Ghosh in the Northern Territory and of C.flavipunctatus, C.fulvusSen and Das Gupta and C.orientalisMacfie in Queensland (Qld) provide evidence of multiple pathways for incursions of biting midges into northern Australia. Of these, only C.fulvus appears to have established. Additionally, three species, C.fulvus, C.wadai Kitaoka and C.brevipalpisDelfinado, are newly reported from PNG and all appear to be well established. The arrival in PNG of C.fulvus and C.brevipalpis, both not previously reported from Qld, suggests that pathways exist for the entry of Oriental insects into New Guinea directly from Asia, rather than via Australia. Molecular analyses using DNA barcodes (partial mitochondrial cytochrome oxidase subunit one sequences) confirmed morphological identification of specimens and additionally provided strong evidence relating to the source of these incursions. At least two of these species are vectors of important livestock viruses and are likely to impact on the epidemiology of these viruses as they continue to disperse. © 2015 Australian Entomological Society.

Bellis G.A.,Northern Australia Quarantine Strategy | Donaldson J.F.,83 Mills Road | Quintao V.,Directorate of Quarantine and Biosecurity | Rice A.,Northern Australia Quarantine Strategy | And 2 more authors.
Austral Entomology | Year: 2014

Examination of Delphacini holdings in Australian insect collections and comparison with material from overseas collections has revealed several species not previously recorded from Australia, Timor Leste and/or Papua New Guinea. Newly recorded species from Australia are Anchodelphax olenus Fennah, Cemus sauteri (Muir), Falcotoya auriniaFennah, Hagamiodes fuscicaudata (Muir), Horcoma colorata lacteipennis (Muir), Latistria placitus (van Duzee), Nemetor sabinusFennah, Nilaparvata bakeri (Muir), Nilaparvata myersi (Muir), Numata corporaali (Muir), Nycheuma coctum (Yang), Perkinsiella bakeri (Muir), Rhombotoya pseudonigripennis (Muir), Tagosodes pusanus (Distant), Toya bridwelli (Muir). Newly recorded species from Timor Leste are Falcotoya aurinia, Horcoma colorata lacteipennis, Latistria placitus, Nycheuma coctum and Tagosodes pusanus. Newly recorded species from Papua New Guinea are Hagamiodes fuscicaudata and Laodelphax striatellus (Fallén). An updated checklist of Australian Delphacini is provided. [Correction added on 19 December 2013, after first online publication: 'Laodelphax striatellus' has been removed from the list of newly recorded species.] © 2013 Australian Entomological Society.

Miyata S.,Japan National Agriculture and Food Research Organization | Kato H.,Japan National Agriculture and Food Research Organization | Davis R.,Northern Australia Quarantine Strategy | Smith M.W.,Bundaberg Research Station | And 2 more authors.
Journal of General Plant Pathology | Year: 2011

'Candidatus Liberibacter asiaticus' is the most widespread of the three species of 'Ca. Liberibacter' that cause citrus greening disease (huanglongbing). To ascertain the phylogenetic relationships among Indian isolates that have higher diversity in the 16S rDNA than Asian isolates of this species, we collected symptomatic leaves from Northeast India, Papua New Guinea and Timor-Leste (East Timor) and detected 'Ca. L. asiaticus' by PCR using primers specific for nusG-rplK genes and 16S rDNA. Phylogenetic analysis with 16S rDNA sequences and single nucleotide polymorphisms of the omp gene region revealed that the Northeast Indian isolates were genetically closer to Asian-common isolates from Japan, Taiwan, and Vietnam than to Indian isolates reported previously. Thus, the Asian-common strains of 'Ca. L. asiaticus' are apparently also present in Northeast India. © 2010 The Phytopathological Society of Japan and Springer.

Katoh H.,Japan National Agriculture and Food Research Organization | Davis R.,Northern Australia Quarantine Strategy | Smith M.W.,Bundaberg Research Station | Weinert M.,Center for Tropical Agriculture | Iwanami T.,Japan National Agriculture and Food Research Organization
Annals of Applied Biology | Year: 2012

Japanese isolates of 'Candidatus Liberibacter asiaticus' have been shown to be clearly differentiated by simple sequence repeat (SSR) profiles at four loci. In this study, 25 SSR loci, including these four loci, were selected from the whole-genome sequence and were used to differentiate non-Japanese samples of 'Ca. Liberibacter asiaticus' (13 Indian, 3 East Timorese, 1 Papuan and 8 Floridian samples). Out of the 25 SSR loci, 13 were polymorphic. Dendrogram analysis using SSR loci showed that the clusters were mostly consistent with the geographical origins of the isolates. When single nucleotide polymorphisms (SNPs) were searched around these 25 loci, only the upstream region of locus 091 exhibited polymorphism. Phylogenetic tree analysis of the SNPs in the upstream region of locus 091 showed that Floridian samples were clustered into one group as shown by dendrogram analysis using SSR loci. The differences in nucleotide sequences were not associated with differences in the citrus hosts (lime, mandarin, lemon and sour orange) from which the isolates were originally derived. © 2012 Association of Applied Biologists.

Onyango M.G.,CSIRO | Onyango M.G.,Deakin University | Aitken N.C.,Australian National University | Jack C.,Australian National University | And 9 more authors.
BMC Genomics | Year: 2016

Background: The advent of genotyping by Next Generation Sequencing has enabled rapid discovery of thousands of single nucleotide polymorphism (SNP) markers and high throughput genotyping of large populations at an affordable cost. Genotyping by sequencing (GBS), a reduced representation library sequencing method, allows highly multiplexed sequencing of genomic subsets. This method has limitations for small organisms with low amounts of genomic DNA, such as the bluetongue virus (BTV) vectors, Culicoides midges. Results: This study employed the GBS method to isolate SNP markers de novo from whole genome amplified Culicoides brevitarsis genomic DNA. The individuals were collected from regions representing two different Australian patterns of BTV strain distribution: the Northern Territory (NT) and the east coast. We isolated 8145 SNPs using GBS. Phylogenetic analysis conducted using the filtered 3263 SNPs revealed the presence of a distinct C. brevitarsis sub-population in the NT and this was confirmed by analysis of mitochondrial DNA. Two loci showed a very strong signal for selection and were unique to the NT population. Bayesian analysis with STRUCTURE indicated a possible two-population cluster. Conclusions: The results suggest that genotyping vectors with high density markers in combination with biological and environmental data is useful. However, more extensive sampling over a wider spatial and temporal range is needed. The presence of sub-structure in populations and loci under natural selection indicates the need for further investigation of the role of vectors in shaping the two Australian systems of BTV transmission. The described workflow is transferable to genotyping of small, non-model organisms, including arthropod vectors of pathogens of economic and medical importance. © 2016 The Author(s).

PubMed | Graham Center for Agricultural Innovation, University of Queensland, Kenya International Livestock Research Institute, Northern Australia Quarantine Strategy and 2 more.
Type: | Journal: Veterinary research | Year: 2015

Bluetongue virus (BTV) is a major pathogen of ruminants that is transmitted by biting midges (Culicoides spp.). Australian BTV serotypes have origins in Asia and are distributed across the continent into two distinct episystems, one in the north and another in the east. Culicoides brevitarsis is the major vector of BTV in Australia and is distributed across the entire geographic range of the virus. Here, we describe the isolation and use of DNA microsatellites and gauge their ability to determine population genetic connectivity of C. brevitarsis within Australia and with countries to the north. Eleven DNA microsatellite markers were isolated using a novel genomic enrichment method and identified as useful for genetic analyses of sampled populations in Australia, northern Papua New Guinea (PNG) and Timor-Leste. Significant (P<0.05) population genetic subdivision was observed between all paired regions, though the highest levels of genetic sub-division involved pair-wise tests with PNG (PNG vs. Australia (FST=0.120) and PNG vs. Timor-Leste (FST=0.095)). Analysis of multi-locus allelic distributions using STRUCTURE identified a most probable two-cluster population model, which separated PNG specimens from a cluster containing specimens from Timor-Leste and Australia. The source of incursions of this species in Australia is more likely to be Timor-Leste than PNG. Future incursions of BTV positive C. brevitarsis into Australia may be genetically identified to their source populations using these microsatellite loci. The vectors panmictic genetic structure within Australia cannot explain the differential geographic distribution of BTV serotypes.

Lu B.,Key Laboratory of Integrated Pest Management on Tropical Crops | Lu B.,Chinese Academy of Sciences | Zhu W.,Key Laboratory of Integrated Pest Management on Tropical Crops | Zhu W.,Chinese Academy of Sciences | And 9 more authors.
Biocontrol Science and Technology | Year: 2014

To optimise the production of Asecodes hispinarum Bouček (Hymenoptera: Eulophidae), a parasitoid of coconut leaf beetle, Brontispa longissima (Gestro) (Coleoptera: Chrysomelidae), some of the factors affecting rates of parasitism, number of offspring produced per host and sex ratio of A. hispinarum were investigated. The numbers and sex ratio of A. hispinarum offspring per host reduced significantly at extreme low humidity (30% relative humidity [RH]), but there was no significant effect on parasitism. Photoperiod had no significant effects on any of the life traits tested. A. hispinarum was able to reproduce via arrhenotoky, and while increasing the proportion of female parents increased the number of parasitoids produced, the proportion of female offspring decreased. Older females showed a lower rate of parasitism than young females, however, maternal age did not affect the number or the sex ratio of offspring. Increasing the number of hosts offered to a pair of parasitoids significantly increased the number of parasitised hosts but decreased the parasitism rate while the sex ratio of progeny was not affected. Present work showed that to maximise the production of female parasitoids, a parasitoid/host ratio of 1:1, using one-day old A. hispinarum at a female/male ratio of 3:1 and RH of at least 55% is recommended. © 2013 © 2013 Taylor & Francis.

Eagles D.,CSIRO | Eagles D.,University of Queensland | Melville L.,Khan Research Laboratories | Weir R.,Khan Research Laboratories | And 5 more authors.
BMC Veterinary Research | Year: 2014

Background: Previous studies investigating long-distance, wind-borne dispersal of Culicoides have utilised outbreaks of clinical disease (passive surveillance) to assess the relationship between incursion and dispersal event. In this study, species of exotic Culicoides and isolates of novel bluetongue viruses, collected as part of an active arbovirus surveillance program, were used for the first time to assess dispersal into an endemic region.Results: A plausible dispersal event was determined for five of the six cases examined. These include exotic Culicoides specimens for which a possible dispersal event was identified within the range of two days - three weeks prior to their collection and novel bluetongue viruses for which a dispersal event was identified between one week and two months prior to their detection in cattle. The source location varied, but ranged from Lombok, in eastern Indonesia, to Timor-Leste and southern Papua New Guinea.Conclusions: Where bluetongue virus is endemic, the concurrent use of an atmospheric dispersal model alongside existing arbovirus and Culicoides surveillance may help guide the strategic use of limited surveillance resources as well as contribute to continued model validation and refinement. Further, the value of active surveillance systems in evaluating models for long-distance dispersal is highlighted, particularly in endemic regions where knowledge of background virus and vector status is beneficial. © 2014 Eagles et al.; licensee BioMed Central Ltd.

McTaggart A.R.,Khan Research Laboratories | Shuey L.S.,Khan Research Laboratories | McKenna S.G.,Northern Australia Quarantine Strategy | Davis R.I.,Northern Australia Quarantine Strategy | Shivas R.G.,Khan Research Laboratories
Australasian Plant Pathology | Year: 2014

A specimen of downy mildew on leaves of Sphagneticola trilobata found in northern Queensland was identified by a systematic approach as a novel species of Plasmopara. A new species, Plasmopara sphagneticolae, is proposed for this specimen, which differs from other species of Plasmopara by morphology, host range, and sequence data from nuclear-ribosomal DNA and mitochondrial DNA. Plasmopara sphagneticolae, together with P. halstedii, are downy mildews found on host species in the tribe Heliantheae (Asteraceae). Plasmopara halstedii causes downy mildew on Helianthus annuus, and is not present on sunflower in Australia. Phylogenetic analysis of the large subunit region of ribosomal DNA showed that P. sphagneticolae was sister to P. halstedii on sunflower. © 2014, Australasian Plant Pathology Society Inc.

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