Austral Entomology最新文献

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.

Vector resistance to insecticides, particularly pyrethroids, is an impediment to malaria control. However, the effects of metabolic insecticide resistance mechanisms on Plasmodium falciparum infection in mosquitoes remain poorly understood. We used the synergist, piperonyl butoxide (PBO) to demonstrate a major role for oxidases in pyrethroid-resistant, blood fed, wild-caught An. gambiae s.l., from the Kilombero valley, Tanzania and further investigated the relationship between CYP4G16 expression (one of the two genes overexpressed in resistant Anopheles mosquitoes) and sporozoite copy number. Blood fed-wild, caught adult An. gambiae s.l. (F0) were allowed to lay eggs. The resulting F1 generation was used for susceptibility-testing using WHO methods, and resistance was confirmed against permethrin, deltamethrin and lambdacyhalothrin (26%–86% mortality). Mosquitoes were fully susceptible (100% mortality) to bendiocarb and pirimiphos methyl. The addition of PBO to the pyrethroid assays fully restored susceptibility. After they had laid eggs, the F0 adults were used to characterise parasite infection and resistance gene expression, both using qPCR. The CYP4G16 gene copy number was significantly higher in Plasmodium infected mosquitoes than their uninfected counterparts (Mann–Whitney, p < 0.0001). However, there was no relationship between CYP4G16 gene copy number and P. falciparum sporozoite copy number (Pearson's r = 0.06361, 95% CI). This study suggests that pyrethroids-treated nets combined with PBO may help overcome major oxidative resistance mechanisms. It is also notable that these oxidative mechanisms are associated with increased Plasmodium infection in mosquitoes.

In the present study, Collartida eowilsoni sp. nov. is described from Guadalcanal (Solomon Islands), which extends the distribution of the genus and the tribe Collartidini as a whole to the Oceanian biogeographic realm. The highly aberrant morphology of the new species required a reassessment of the diagnostic characters and generic limits of Collartida. To evaluate the systematic position of C. eowilsoni sp. nov. a morphology-based cladistic analysis was performed, for which homologies of cephalic armature were reinterpreted. Phylogenetic relationships of the new species to its congeners and among other members of the tribe are discussed.

Apulvillasilus gen. nov. is proposed as a new monotypic Asilinae genus from Argentina, based on Apulvillasilus boharti sp. nov. The new genus is separated from other Asilinae genera mainly by the absence of empodia and pulvilli. Its placement in the Myaptex group is proposed. Description, diagnosis, images of the habitus, male and female terminalia, a distribution map, and an updated key for the genera of the Myaptex group are provided.

Filicicapsus smaragdus gen. et sp. nov. (Orthotylinae) is described from the Biak Island, Papua Province of Indonesia. The position of the new taxon has been tested using Bayesian and IQ-TREE analyses based on the sequences of four fragments of mitochondrial (COI, 16S) and nuclear (18S, 28S) DNA. The taxonomic position of the new genus within the Zanchius genus group is discussed. Also provided are a diagnosis, photographs of habitus and selected structures, illustrations of male and female genitalia, scanning electron micrographs of diagnostic characters, and host information.

No abstract is available for this article.

Ovaustra aurantia Tetley, Glatz & Fagan-Jeffries, gen. et sp. nov. (Mesostoinae) is described from Kangaroo Island. South Australia, Australia, and is a solitary, koinobiont, egg-larval parasitoid of the enigma moth, Aenigmatinea glatzella Kristensen & Edwards, 2015, in the monotypic family Aenigmatineidae Kristensen & Edwards, 2015 (Lepidoptera). Female parasitoids oviposit into the eggs of A. glatzella soon after female moths place them beneath minute adpressed leaves at the growing foliar tips of the larval host plant Callitris gracilis R.T. Baker (Cupressaceae). Adult parasitoids emerge from A. glatzella larval chambers located directly beneath the bark of small branches, some way from the growing tip. Adults can be seen on or near foliage of C. gracillis primarily during October and coinciding with the presence of adult host moths. Morphological and preliminary molecular evidence place Ovaustra Glatz, Fagan-Jeffries & Tetley, gen. nov. within Mesostoinae s.l. and indicate that its closest relatives are likely to reside within a group of genera from Australia and New Zealand whose hosts and biology are not well defined but are apparently quite broad, including lepidopteran, coleopteran and dipteran larvae, as well as primary plant gall induction.