School of BioSciences - Research Publications
Permanent URI for this collection
Search Results
1 - 10 of 46
-
ItemNo Preview AvailableDiscovery of insecticide resistance in field-collected populations of the aphid pest, Acyrthosiphon kondoi Shinji(JOHN WILEY & SONS LTD, 2024-03)
-
ItemNo Preview AvailableMolecular identification of hymenopteran parasitoids and their endosymbionts from agromyzids(Cambridge University Press, 2023-08)Three polyphagous pest Liriomyza spp. (Diptera: Agromyzidae) have recently invaded Australia and are damaging horticultural crops. Parasitic wasps are recognized as effective natural enemies of leafmining species globally and are expected to become important biocontrol agents in Australia. However, the hymenopteran parasitoid complex of agromyzids in Australia is poorly known and its use hindered due to taxonomic challenges when based on morphological characters. Here, we identified 14 parasitoid species of leafminers based on molecular and morphological data. We linked DNA barcodes (5′ end cytochrome c oxidase subunit I (COI) sequences) to five adventive eulophid wasp species (Chrysocharis pubicornis (Zetterstedt), Diglyphus isaea (Walker), Hemiptarsenus varicornis (Girault), Neochrysocharis formosa (Westwood), and Neochrysocharis okazakii Kamijo) and two braconid species (Dacnusa areolaris (Nees) and Opius cinerariae Fischer). We also provide the first DNA barcodes (5′ end COI sequences) with linked morphological characters for seven wasp species, with three identified to species level (Closterocerus mirabilis Edwards & La Salle, Trigonogastrella parasitica (Girault), and Zagrammosoma latilineatum Ubaidillah) and four identified to genus (Aprostocetus sp., Asecodes sp., Opius sp. 1, and Opius sp. 2). Phylogenetic analyses suggest C. pubicornis, D. isaea, H. varicornis, and O. cinerariae are likely cryptic species complexes. Neochrysocharis formosa and Aprostocetus sp. specimens were infected with Rickettsia. Five other species (Cl. mirabilis, D. isaea, H. varicornis, Opius sp. 1, and Opius sp. 2) were infected with Wolbachia, while two endosymbionts (Rickettsia and Wolbachia) co-infected N. okazakii. These findings provide background information about the parasitoid fauna expected to help control the leafminers.
-
ItemFungicides have transgenerational effects on Rhopalosiphum padi but not their endosymbionts(JOHN WILEY & SONS LTD, 2022-11)
-
ItemA working guide to spatial mechanistic modelling in Julia(Wiley Open Access, 2022-05)Models that can predict the dynamics of larger scale ecological processes are increasingly important in a rapidly changing world. The Julia language gives a unique opportunity to produce new, generic tools to develop spatial mechanistic models, and to simultaneously increase their performance, resolution and predictive power. Here, we describe two new Julia software packages, DynamicGrids.jl and Dispersal.jl, that facilitate the development of spatial mechanistic models that are concise, extensible and performant, with several key attributes. First, they allow arbitrary spatially and temporally heterogeneous inputs (e.g. regional climatic data to drive population dynamics). Second, they apply rules to discrete spatial grids, including: (a) single grid cells (e.g. population growth, Allee effects, land‐use change), (b) neighborhoods (e.g. local dispersal); and (c) arbitrary locations (e.g. long‐distance wind dispersal, human‐mediated dispersal). Finally, they allow interactions between multiple grids (e.g. predator–prey models, management/environmental feedbacks). Through in‐line examples, we explore how these properties can be used to develop simple and complex grid‐based mechanistic models that run on both CPUs and GPUs. We demonstrate models of population growth, wind and self‐directed dispersal and host–parasitoid dynamics. We also demonstrate the ease by which custom rules can be combined with rules provided by packages, and the potential for use in other fields and interdisciplinary research. These Julia packages provide concise, extensible and performant tools for a wide range of grid‐based spatial models in ecology and beyond. More broadly, they highlight new opportunities for ecological modelling using the Julia language, with its combination of clear syntax, extensibility from its solution to the expression problem and its performance on CPUs and GPUs.
-
Item
-
ItemThe redlegged earth mite draft genome provides new insights into pesticide resistance evolution and demography in its invasive Australian range(WILEY, 2023-02)Genomic data provide valuable insights into pest management issues such as resistance evolution, historical patterns of pest invasions and ongoing population dynamics. We assembled the first reference genome for the redlegged earth mite, Halotydeus destructor (Tucker, 1925), to investigate adaptation to pesticide pressures and demography in its invasive Australian range using whole-genome pool-seq data from regionally distributed populations. Our reference genome comprises 132 autosomal contigs, with a total length of 48.90 Mb. We observed a large complex of ace genes, which has presumably evolved from a long history of organophosphate selection in H. destructor and may contribute towards organophosphate resistance through copy number variation, target-site mutations and structural variants. In the putative ancestral H. destructor ace gene, we identified three target-site mutations (G119S, A201S and F331Y) segregating in organophosphate-resistant populations. Additionally, we identified two new para sodium channel gene mutations (L925I and F1020Y) that may contribute to pyrethroid resistance. Regional structuring observed in population genomic analyses indicates that gene flow in H. destructor does not homogenize populations across large geographic distances. However, our demographic analyses were equivocal on the magnitude of gene flow; the short invasion history of H. destructor makes it difficult to distinguish scenarios of complete isolation vs. ongoing migration. Nonetheless, we identified clear signatures of reduced genetic diversity and smaller inferred effective population sizes in eastern vs. western populations, which is consistent with the stepping-stone invasion pathway of this pest in Australia. These new insights will inform development of diagnostic genetic markers of resistance, further investigation into the multifaceted organophosphate resistance mechanism and predictive modelling of resistance evolution and spread.
-
Item
-
ItemGenome-wide SNPs of vegetable leafminer, Liriomyza sativae: Insights into the recent Australian invasion(WILEY, 2022-07)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.
-
ItemWarmer temperatures reduce chemical tolerance in the redlegged earth mite (Halotydeus destructor), an invasive winter-active pest(JOHN WILEY & SONS LTD, 2022-07)
-
Item
- 1 (current)
- 2
- 3
- 4
- 5