Austral Entomology最新文献

No abstract is available for this article.

Determining the identity of potential control agents is critical to successful biological control and can contribute to our understanding of the failures of previous introductions, especially in cases where host-associated cryptic species may be present. In 1975, a mealybug was introduced into Australia from Argentina for the classical biological control of the invasive cactus Harrisia martinii (Cactaceae). This cactus also originates from Argentina and is an environmental and agricultural weed in parts of Australia. Since its release, the imported mealybug species has been incorrectly referred to as Hypogeococcus festerianus (Hemiptera: Pseudococcidae) in the applied literature, and its performance as a biological control agent has been considered poor in some locations. In this study, the identities of mealybug specimens collected from 10 locations in Queensland and New South Wales, Australia, were assessed. The genetic, morphological and reproductive characteristics of these specimens were compared with those of two congeneric mealybug species, Hypogeococcus pungens sensu stricto (Hemiptera: Pseudococcidae) and Hypogeococcus festerianus. Specimens from the different Australian localities examined were all very similar to each other morphologically and genetically, based on comparisons of mitochondrial and nuclear DNA sequence data. The morphological features of all the specimens were typical of Hypogeococcus pungens sensu stricto. H. pungens is now considered to constitute a species complex, and the specimens from Australia are genetically similar to the Cactaceae clade of this species complex from Argentina. In common with H. pungens s. s., the insects collected in Australia can also reproduce parthenogenetically. These findings help confirm that all populations of the mealybug in Australia are not H. festerianus, but part of the H. pungens cryptic species complex. There is no mismatch between this agent and the host plant in Australia, as H. martinii is one of the host plants of the most closely related cryptic species of H. pungens in the native range in Argentina. Thus, despite the original confusion around its identity, the variable performance of the introduced mealybug as a biological control agent of H. martini in Australia is likely due to other factors, and these require further investigation.

‘Slow science’ approaches to generating authoritative longitudinal datasets for long-term monitoring are fundamental to conservation biology. Following reports of significant arthropod declines worldwide, and recent climate-driven disasters such as the devastating ‘Black Summer’ bushfires of 2019–2020, there has been a renewed focus on invertebrate conservation in Australia and further calls for informative baseline datasets with which to understand increasingly rapid biotic change. Trapdoor spiders of the infraorder Mygalomorphae, in particular, have been the subject of decades of research highlighting their sensitivity to environmental change and their special significance to conservation biology. In 2019, the senior author and collaborators introduced within this journal a new long-term monitoring study system for an Australian mygalomorph spider (Euoplos grandis Wilson & Rix, 2019; family Idiopidae), then in its infancy with just 18 months of quantitative demographic data. In the current study, we extend and build upon that work and provide a synthesis of demographic information accumulated over half a decade, resulting in 166 collective years' worth of times-series data from 101 individual spiders. We infer an estimated average cumulative growth curve for the species based on census data from 77 spiders, with evidence for a 7+-year juvenile female growth period and a potential life span for adult females of over 20 years. Passive surveillance using a camera trap deployed at the study site for 8 months resulted in significant advances in our understanding of the biology and behaviour of E. grandis, with a suite of behaviours observed for the first time, including rarely documented interactions with conspecifics, potential predators and prey. We further summarise the results of maximum entropy potential habitat modelling as informed by extensive on-ground surveys and a refined taxonomy, and provide an updated conservation assessment using the International Union for Conservation of Nature (IUCN) criteria. These results reveal that E. grandis is a Vulnerable threatened species endemic to the highly fragmented southern Brigalow Belt bioregion, with population dynamics and life history characteristics that underscore the considerable sensitivity of Australian idiopid trapdoor spiders to a multitude of threatening processes.

The development of the field of biological control of weeds in Australia is described, from the first attempts in 1903 to the present day. The interest sparked by the obvious success of prickly pear program, apparent from 1930 to 1935, resulted in several programs during the next 20 years, followed by a decline in activity until the 1970s when activity increased enormously following the success of the skeleton weed program and the effective use of a plant pathogen for the first time. This momentum was maintained until the beginning of the present century with several successes and was marked by several important advances in genetic profiling, host-specificity testing, economic evaluation, conflict of interest resolution and the ecology of insect/plant interactions, including evaluation of the effectiveness of individual introductions. Biological control has proved to be a valuable and effective approach to weed management in Australia with 39% of all programs considered to produce complete or near-complete control, 30.5% partial control and an average benefit–cost ratio of 23:1. Funding for research has been variable with a decline from the late 1990s but with a significant increase again since 2020.

Mosquitoes are found worldwide; in Brazil, 530 species are distributed across all its biomes. Understanding of the biodiversity of the Caatinga biome remains incomplete, especially for Culicidae. We carried out a sampling of immature and adult mosquitoes in aquatic habitats and using Shannon traps in a seasonally dry tropical forest, in the semiarid of Rio Grande do Norte. A total of 1747 immatures of 13 species were collected during the study period (2017–2020) in groundwater sites, rock depressions, with and without vegetation, and tree holes. The maintenance of temporary breeding sites is related to the dry and rainy seasons. We collected 2132 adult mosquitoes of 12 species between 5 and 8 PM. Correlation analyses showed the effect of meteorological variables on Culicidae populations. Both immature and adult mosquitoes' abundance were significantly influenced by temperature and wind. The abundance of adult mosquitoes of the genera Aedes demonstrated a positive correlation with temperature, and a negative one with Mansonia and Uranotaenia. Our study adds information on the population dynamics of mosquitoes in the Brazilian semiarid, highlighting the bioecological relationships and breeding sites of species relevant to public health.

The homoterpenes 4,8-dimethyl-1,3,7-nonatriene (DMNT) and 4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMTT) are volatile products of plant metabolism reported from diverse plant taxa and multiple plant tissues. As such, they have a range of potential ecological functions. Here, we review the key literature to assess evidence for roles in contrasting plant–arthropod interactions. TMTT, and DMNT especially, have been reported as sometimes dominant constituents of floral scents from angiosperm taxa ranging from primitive Magnoliales to more advanced, taxonomic orders of economic significance such as Fabales and Sapindales. Although all taxa producing TMTT and DMNT in floral scents are entomophilous (‘insect pollinated’), experimental evidence for an assumed role of these homoterpenes in pollinator attraction is limited. Representing a trade-off, in some cases, homoterpenes in floral scents have been shown to act as kairomones, attracting herbivores. Additionally, both TMTT and DMNT are released by plant foliage in response to arthropod feeding, mechanical damage simulating feeding, or even egg deposition. Evidence for a functional role in herbivore-induced plant volatile (HIPV) blends comes from a wide range of angiosperm orders, including anemophilous (‘wind pollinated’) taxa, as well as from gymnosperms. We conclude by considering how TMTT and DMNT function in community-level interactions and highlighting research priorities that will reveal how plants avoid trade-offs from contrasting ecological functions of DMNT and TMTT release and how homoterpene production might be exploited to develop improved crop varieties.

Three species of polyphagous Liriomyza leafminers (Diptera: Agromyzidae), Liriomyza huidobrensis, L. sativae, and L. trifolii, are internationally significant pests of vegetable and nursery crops that have each been recently detected on the Australian mainland. Due to the early stages of these invasions in Australia, it is unclear how climatic conditions are likely to support and potentially restrict the distribution of these species as they expand into novel ranges and threaten agricultural production regions. Additionally, it is unclear how natural enemies, particularly parasitoid wasps, will mitigate the impacts of these pests. Here, we predicted the future establishment potential of L. huidobrensis, L. sativae and L. trifolii in Australia, as well as two cosmopolitan parasitoid wasps known to provide control of the flies in both field and glasshouse settings, Diglyphus isaea (Hymenoptera: Eulophidae) and Hemiptarsenus varicornis (Hymenoptera: Eulophidae). Global distribution data spanning 42 countries were compiled and used to validate a process-based model of establishment potential based on intrinsic population growth rates. The modelling approach successfully captured the international distribution of the three Liriomyza species based on environmental variables and predicted the high suitability of non-occupied ranges in Australia. The largely unfilled climatic niche available to these pests demonstrates the early stages of their Australian invasions and highlights locations where vegetable production regions are at particular risk. In addition to Australia, our results highlight many regions globally where L. sativae, L. trifolii and L. huidobrensis have the potential to spread in the future. Within Australia, D. isaea and H. varicornis are predicted to have a large spatial and seasonal overlap with each Liriomyza species and thus are expected to influence the future spread of these pests and play an important role in local pest management programs.

Mosquitoes (Diptera: Culicidae) pose a serious threat to human health globally and the accurate identification of mosquito species is fundamental to entomological diagnostics and surveillance implementing effective vector control and management. However, cryptic species complexes, incomplete or damaged specimens, and juvenile life stages complicates the task. Molecular characterisation has shown the potential to identify the mosquito species accurately and overcomes the difficulties that morphological diagnosis face. Here, we assessed the effectiveness of a multi-locus barcoding approach using cytochrome c oxidase subunit I (COI), internal transcribed spacer 1 (ITS1) and internal transcribed spacer 2 (ITS2) regions to identify the New Zealand mosquito species (n = 16) at the highest taxonomic resolution, which can make diagnosis more accurate and efficient. Our results show that most of the New Zealand mosquito species could be distinctly separated from each other as well as from other exotic species using either of these barcoding regions (i.e., COI, ITS1 and ITS2). The assessment of taxonomic discriminatory power of COI, ITS1 and ITS2 barcodes suggests that ITS2 can better distinguish the New Zealand closely-related species. Two closely-related endemic species from the Culex pervigilans species complex (Cx. rotoruae and Cx. pervigilans) were difficult to distinguish using COI and ITS1 regions. However, the ITS2 barcode could detect a greater genetic variation among individuals of those two species and demonstrate the potential to resolve the relationships among them to provide better resolution as a complementary to COI. Overall, this study provides a reference DNA barcode database of COI and ITS2 for New Zealand mosquito species, which will aid in their accurate identification at a higher taxonomic resolution and corroborate the traditional morphological approaches to perform better species discrimination among closely-related species complex. The study also assessed the preliminary genetic diversity of the mosquito species from different regions of New Zealand, which can be used as a baseline for uncovering the environmental and geographical effect on genomic variations among New Zealand mosquito populations in the future.

The baseline distribution data for all species of a given group in a region can provide fundamental insights into biogeographic questions about historic patterns of species richness, population trends and extinction. Grasshoppers are one major group of insects for which a continent-wide perspective on their geographic distribution can be obtained. This is because they were extensively surveyed in Australia for 54 years (1936–1989) as part of Commonwealth expeditions to obtain specimens for the Australian National Insect Collection (ANIC). Field notebooks recorded from those surveys, under the direction of ANIC curator and director K. H. L. Key, form the principal source of historic distribution records for grasshoppers in Australia. We digitised all the 223 notebooks (2486 pages) and transcribed all the field trips conducted in Western Australia (WA) and Tasmania (47 notebooks, 590 pages). We then carefully geocoded all sampling sites of the transcribed notebooks, following the odometer readings and descriptions of routes from a suitable reference point using historic topographic maps and Google Earth. In total, we extracted 8975 geographic coordinates for 477 species having a confirmed or putative taxonomic name at genus or species level (only 170 of these species have been formally described). We found that species richness varied spatially, with highest richness in arid interior and north of WA. Historic grasshopper surveys were non-randomly distributed across both WA and Tasmania with the highest survey intensity around coastal regions. Variation was observed among surveyors in terms of the number of species detected per site, between-site distance and the season of survey being conducted. Overall, however, the dataset is among the most comprehensive continent-wide surveys of Australian invertebrates and will greatly facilitate future work on their ecology, biogeography, conservation and responses to environmental change.