Austral Entomology最新文献

Serpentine leaf miner, Liriomyza huidobrensis, invaded New South Wales and Queensland late 2020. Overseas, L. huidobrensis has a history of developing insecticide resistance and, since its Australian discovery, has caused significant control issues in Australian horticultural industries. Here, we developed bioassay methods to test the response of L. huidobrensis larvae to spirotetramat and L. huidobrensis adults to dimethoate, imidacloprid and chlorantraniliprole. Against two New South Wales and one Queensland collected strains, we found a 33-fold elevated response against dimethoate and 200-fold more against imidacloprid than the field-recommended field rates. Furthermore, we found that a maximum rate of 64-fold the field-recommended rate of chlorantraniliprole controlled only 94% of one tested population. Similarly, the maximum rate of spirotetramat tested (64-fold the field-recommended rate) only achieved 84%–94% mortality for the same populations. Prior to our study, the efficacy of chlorantraniliprole and spirotetramat against Liriomyza was poorly studied, with only a few reports with chlorantraniliprole against Liriomyza trifolii. Consequently, none of the tested insecticides in this study will likely control Australian invasive L. huidobrensis at the field-recommended rates. Our results presented here highlight the need to identify and study alternative chemical and biological products and natural enemies for the control of L. huidobrensis in Australian horticulture.

The bogong moth, Agrotis infusa, an endemic noctuid moth of Australia, is known for its extensive long-distance movement and summer aestivation in the Australian Alps. Recent studies have focused on moth activity in the Alps, but there are limited data for other regions. This study aims to build on the current understanding of bogong moth movement and breeding patterns using unpublished historical data across eastern Australia. We analysed historical data from moth traps in Victoria, New South Wales (NSW) and South Australia (SA) from the 1960s to early 1990s. The study employed the HYSPLIT model for trajectory analysis of moth flight paths and DARABUG2 for phenological modelling. We examined moth catches across different seasons to infer movement patterns, breeding sources and over-summering activity. Our findings question several long-standing assumptions about the spatial ecology of the bogong moth. The trajectory analysis suggests that many aspects of A. infusa movement can be explained via dynamic migration, without fully relying on inherent navigation abilities. Important breeding areas may be beyond the self-mulching clays of NSW and southern Queensland and include far western NSW, south and central SA and southern Victoria. Substantial moth activity during summer in many traps suggests alternative over-summering strategies including local breeding or even aestivation in areas other than the Alps. Furthermore, the autumn and winter data imply return migrations from diverse source areas and potential local breeding, expanding the understanding of the moth's life cycle beyond a univoltine pattern. In conclusion, the bogong moth appears to exhibit a more complex and adaptable migration and breeding strategy than previously understood, utilising a range of habitats across eastern Australia for breeding and possibly aestivation. This underscores the need for a revised understanding of bogong moth ecology, which is crucial for its conservation and management, especially considering its recent classification as ‘Endangered’ on the IUCN Red List.

Pterocomma (Hemiptera: Aphidinae) are large aphids found across the northern hemisphere on various willow (Salix) and poplar (Populus) trees. We provide the first records of the Poplar Bark Aphid, Pterocomma populeum in Australia from Tasmania and New South Wales, a potential pest of poplar trees. Morphological character measurements and DNA (cytochrome oxidase subunit 1) sequences are provided along with discussions around difficulties in species separation.

With higher frequency and intensity of droughts predicted for many tropical forests, understanding the responses of plants and animals to changed climatic conditions will be increasingly important. Ants are considered ecosystem engineers in tropical rainforests due to their abundance and the diversity of functional roles they perform. Function in animals is often dictated by diet, with diets of rainforest ants ranging from purely carnivorous to mostly plant based. Stable isotopes of nitrogen and carbon have been utilised to infer information on diets, and more broadly on changes in ecosystem dynamics and water-use in plants. We used stable isotopes to investigate the potential effects of drought on the diets of two dominant ant species (Anonychomyrma gilberti and Oecophylla smaragdina) in an in-situ through-fall experiment in lowland rainforest. We observed a significant and sustained increase of δ¹⁵N in both ant species in the drought experiment and during the dry season in the control treatment. We also detected elevated although much smaller levels of δ¹⁵N values in leaves of some drought-stressed plant species. There was no detectable difference of the experiment for ant or plant δ¹³C values. We conclude that the observed elevation in ants' δ¹⁵N in response to drought may be partly caused by a drought-induced shift in δ¹⁵N in plants. Although, with average nitrogen enrichment values of 2.7‰ and 3.2‰, for A. gilberti and O. smaragdina, respectively, it is consistent with these ants deriving nitrogen largely from prey. Because ants are such dominant species in rainforests, even small trophic shifts in response to climate change if widespread could have broad implications for species interactions and food webs. Importantly, it is possible that such a change could potentially mediate the effects of drought on tropical forests if herbivory on drought-stressed plants is diminished by ant predation.

Pyrethroid resistance in the redlegged earth mite (Halotydeus destructor) continues to be a persistent and expanding problem across the grain belt of Australia, requiring ongoing monitoring to detect emerging local resistance issues. Detection of field resistance in H. destructor currently relies upon the collection and transport of live mites, followed by laborious experiments involving laboratory pesticide bioassays or fairly complex genetic screening assays. Both approaches require trained scientists and are time-consuming and therefore do not provide rapid feedback to farmers. To facilitate the rapid detection of resistance issues, we developed a novel bioassay that can be readily applied in the field using commercially available materials and without the need for training. Although effective in detecting field resistance, this approach was found to be unsuitable in situations where the resistance allele frequency within a mite population was low. To address this limitation, we developed a loop-mediated isothermal amplification (LAMP)-based assay. This approach was successful in distinguishing between homozygote (SS) and heterozygote (RS) mites and, therefore, capable of detecting resistance at low frequency. These tools should help in the ongoing real-time monitoring of resistance in this important agricultural pest.

Termites are important ecosystem engineers in many ecosystems globally. Hence, surveys of termite species composition, abundance and activity can be important for understanding ecosystem function—especially in biomes where they tend to be abundant, such as tropical savannas. However, comprehensively surveying termites can be challenging due to their cryptic nature and varied feeding and nesting habits, which strongly influence the effectiveness of different survey methods. Baiting and active searches of reduced transects are two methods commonly used to sample termites, and while these methods have been evaluated in the savannas of South Africa, this has not occurred in the extensive tropical savannas of northern Australia. Thus, this study evaluated the effectiveness of baits and reduced transects to assess termite species richness and activity across 18 × 1 ha experimental plots in a tropical savanna near Darwin, Australia. Surveys in each plot consisted of two 60 × 2 m transects and a 9 × 3 baiting grid of alternating buried wood and paper baits and surface straw baits. Baits were checked three times: at 4-, 7- and 10-week intervals following placement. Upon survey completion, the sampling effort, efficacy and costs of each method were compared. Reduced transects detected all 32 species recorded in this study, representing four feeding groups (from undecayed wood to highly decayed organic material in the soil). Baiting detected 20 species, but failed to detect some of the species that fed on decayed materials. Paper baits, checked only twice (at 4 and 10 weeks following placement), were required to detect all species sampled at both wood and paper baits. Therefore, overall baiting costs could be reduced (without data loss) by using paper baits only and reducing the number of bait checks. Compared with baiting using all three bait types, reduced transects detected the most species and had the lowest per-species cost. Consequently, reduced transect surveys are the most effective method in these northern Australian savannas when assessing species composition. However, if the abundance of species that feed on undecayed wood or levels of termite activity are being assessed, then reduced baiting is a more appropriate method.

No abstract is available for this article.

Seven new species of Rhopalomyia Rübsaamen, 1892 are described from eastern Australia feeding on a diverse range of plant genera and families. All induce galls on flower or growth buds: Rhopalomyia cassiniae Adair & Kolesik, sp. nov. on Cassinia subtropica (Asteraceae), Rhopalomyia digitata Adair & Kolesik, sp. nov. on Podolobium ilicifolium (Fabaceae), Rhopalomyia glebosa Adair & Kolesik, sp. nov. on Parsonsia straminea (Apocynaceae), Rhopalomyia inconspicua Adair & Kolesik, sp. nov. on Kunzea sp. (Myrtaceae), Rhopalomyia ozothamniae Adair & Kolesik, sp. nov. on Ozothamnus ferrugineus (Asteraceae), Rhopalomyia pultenicola Adair & Kolesik, sp. nov. on Pultenaea forsythiana (Fabaceae) and Rhopalomyia stypheliae Adair & Kolesik, sp. nov. on Syphelia triflora (Ericaceae). The scope of Rhopalomyia is broadened to contain species with a partially setulose gonostyle and a four-segmented palp, a decision supported by a phylogenetic analysis based on the barcoding section of the mitochondrial COI gene. Apocynaceae, Ericaceae, Fabaceae and Myrtaceae are recorded as hosts of Rhopalomyia for the first time.