School of BioSciences - Research Publications

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    Genome-wide SNPs of vegetable leafminer, Liriomyza sativae: Insights into the recent Australian invasion
    Xu, X ; Schmidt, TL ; Liang, J ; Ridland, PM ; Chung, J ; Yang, Q ; Jasper, ME ; Umina, PA ; Liu, W ; Hoffmann, AA (WILEY, 2022-06-28)
    Liriomyza sativae, the vegetable leafminer, is an important agricultural pest originally from the Americas, which has now colonized all continents except Antarctica. In 2015, L. sativae arrived on the Australian mainland and established on the Cape York Peninsula in the northeast of the country near the Torres Strait, which provides a possible pathway for pests to enter Australia and evade biosecurity efforts. Here, we assessed genetic variation in L. sativae based on genome-wide single nucleotide polymorphisms (SNPs) generated by double digest restriction-site-associated DNA sequencing (ddRAD-seq), aiming to uncover the potential origin(s) of this pest in Australia and contribute to reconstructing its global invasion history. Our fineRADstructure results and principal component analysis suggest Australian mainland populations were genetically close to populations from the Torres Strait, whereas populations from Asia, Africa, and Papua New Guinea (PNG) were more distantly related. Hawaiian populations were genetically distinct from all other populations of L. sativae included in our study. Admixture analyses further revealed that L. sativae from the Torres Strait may have genetic variation originating from multiple sources including Indonesia and PNG, and which has now spread to the Australian mainland. The L. sativae lineages from Asia and Africa appear closely related. Isolation-by-distance (IBD) was found at a broad global scale, but not within small regions, suggesting that human-mediated factors likely contribute to the local spread of this pest. Overall, our findings suggest that an exotic Liriomyza pest invaded Australia through the Indo-Papuan conduit, highlighting the importance of biosecurity programs aimed at restricting the movement of pests and diseases through this corridor.
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    Australian Bryobia mites (Trombidiformes: Tetranychidae) form a complex of cryptic taxa with unique climatic niches and insecticide responses
    Umina, PA ; Weeks, AR ; Maino, JL ; Hoffmann, AA ; Song, SV ; Thia, J ; Severtson, D ; Cheng, X ; van Rooyen, A ; Arthur, AA (JOHN WILEY & SONS LTD, 2022-04-22)
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    Warmer temperatures reduce chemical tolerance in the redlegged earth mite (Halotydeus destructor), an invasive winter-active pest
    Thia, JA ; Cheng, X ; Maino, J ; Umina, PA ; Hoffmann, AA (JOHN WILEY & SONS LTD, 2022-04-29)
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    Climate contributes to the evolution of pesticide resistance
    Maino, JL ; Umina, PA ; Hoffmann, AA (WILEY, 2018-02-01)
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    The mitogenome of Halotydeus destructor (Tucker) and its relationships with other trombidiform mites as inferred from nucleotide sequences and gene arrangements
    Thia, JA ; Young, ND ; Korhnen, PK ; Yang, Q ; Gasser, RB ; Umina, PA ; Hoffmann, AA (WILEY, 2021-09-22)
    The redlegged earth mite, Halotydeus destructor (Tucker, 1925: Trombidiformes, Eupodoidea, Penthaleidae), is an invasive mite species. In Australia, this mite has become a pest of winter pastures and grain crops. We report the complete mitogenome for H. destructor, the first to represent the family Penthaleidae, superfamily Eupodoidea. The mitogenome of H. destructor is 14,691 bp in size, and has a GC content of 27.87%, 13 protein-coding genes, two rRNA genes, and 22 tRNA genes. We explored evolutionary relationships of H. destructor with other members of the Trombidiformes using phylogenetic analyses of nucleotide sequences and the order of protein-coding and rRNA genes. We found strong, consistent support for the superfamily Tydeoidea being the sister taxon to the superfamily Eupodoidea based on nucleotide sequences and gene arrangements. Moreover, the gene arrangements of Eupodoidea and Tydeoidea are not only identical to each other but also identical to that of the hypothesized arthropod ancestor, showing a high level of conservatism in the mitogenomic structure of these mite superfamilies. Our study illustrates the utility of gene arrangements for providing complementary information to nucleotide sequences with respect to inferring the evolutionary relationships of species within the order Trombidiformes. The mitogenome of H. destructor provides a valuable resource for further population genetic studies of this important agricultural pest. Given the co-occurrence of closely related, morphologically similar Penthaleidae mites with H. destructor in the field, a complete mitogenome provides new opportunities to develop metabarcoding tools to study mite diversity in agro-ecosystems. Moreover, the H. destructor mitogenome fills an important taxonomic gap that will facilitate further study of trombidiform mite evolution.
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    High Incidence of Related Wolbachia across Unrelated Leaf-Mining Diptera
    Xu, X ; Ridland, PM ; Umina, PA ; Gill, A ; Ross, PA ; Pirtle, E ; Hoffmann, AA (MDPI, 2021-09-01)
    The maternally inherited endosymbiont, Wolbachia pipientis, plays an important role in the ecology and evolution of many of its hosts by affecting host reproduction and fitness. Here, we investigated 13 dipteran leaf-mining species to characterize Wolbachia infections and the potential for this endosymbiont in biocontrol. Wolbachia infections were present in 12 species, including 10 species where the Wolbachia infection was at or near fixation. A comparison of Wolbachia relatedness based on the wsp/MLST gene set showed that unrelated leaf-mining species often shared similar Wolbachia, suggesting common horizontal transfer. We established a colony of Liriomyza brassicae and found adult Wolbachia density was stable; although Wolbachia density differed between the sexes, with females having a 20-fold higher density than males. Wolbachia density increased during L. brassicae development, with higher densities in pupae than larvae. We removed Wolbachia using tetracycline and performed reciprocal crosses between Wolbachia-infected and uninfected individuals. Cured females crossed with infected males failed to produce offspring, indicating that Wolbachia induced complete cytoplasmic incompatibility in L. brassicae. The results highlight the potential of Wolbachia to suppress Liriomyza pests based on approaches such as the incompatible insect technique, where infected males are released into populations lacking Wolbachia or with a different incompatible infection.
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    Origin of resistance to pyrethroids in the redlegged earth mite (Halotydeus destructor) in Australia: repeated local evolution and migration
    Yang, Q ; Umina, PA ; Rasic, G ; Bell, N ; Fang, J ; Lord, A ; Hoffmann, AA (JOHN WILEY & SONS LTD, 2019-07-01)
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    Identifying critical research gaps that limit control options for invertebrate pests in Australian grain production systems
    Macfadyen, S ; Moradi-Vajargah, M ; Umina, P ; Hoffmann, A ; Nash, M ; Holloway, J ; Severtson, D ; Hill, M ; Van Helden, M ; Barton, M (WILEY, 2019-02-01)
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    Escalating insecticide resistance in Australian grain pests: contributing factors, industry trends and management opportunities
    Umina, PA ; McDonald, G ; Maino, J ; Edwards, O ; Hoffmann, AA (JOHN WILEY & SONS LTD, 2019-06-01)
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    Climate, human influence and the distribution limits of the invasive European earwig, Forficula auricularia, in Australia
    Hill, MP ; Binns, M ; Umina, PA ; Hoffmann, AA ; Macfadyen, S (JOHN WILEY & SONS LTD, 2019-01-01)