Austral Entomology最新文献

Tarantulas (Araneae: Theraphosidae) are one of the most diverse and widespread families of mygalomorph spiders, with over 1000 species recognised globally. While tarantulas can be found across most of mainland Australia, from arid regions to tropical forests, the Australian fauna are not yet well characterised. There are currently only 10 nominal species, up to 8 of which are currently recognised as distinct species. Here, we aim to undertake the first continent-wide assessment of species diversity of tarantulas in Australia using an iterative, hypothesis-testing approach. We apply a biological species concept and use DNA sequence data from three independent loci to delimit putative species based on evidence of lack of gene flow. First, we use the mitochondrial DNA marker 16S to identify a set of putative species hypotheses. We then test each hypothesis under the expectations of neotypy, allotypy and allophyly using two independent nuclear loci, EF1γ and 28S rRNA. Genealogically exclusive lineages are inferred using haplotype networks for each nuclear locus, interpreted to represent non-interbreeding entities and hence represent distinct biological species. We find evidence for there being at least 20 distinct biological species of tarantula in Australia, with the highest species richness in northern Australia. Our results are in line with other DNA-based studies of Australian mygalomorphs that have uncovered undescribed species diversity. Given the low number of samples included here, there is likely to be an even greater species diversity of tarantulas in Australia.

Frugivorous insects use visual, chemical and tactile cues to find a suitable host for oviposition. However, these cues can vary greatly among fruit cultivars and condition, changing their susceptibility to fruit fly oviposition. The aims of this study were to (1) determine the effects of ripeness stage and damage on oviposition propensity by sexually mature, mated female oriental fruit flies, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), on five citrus types (species and cultivars) under choice and no-choice conditions and (2) describe the oviposition behaviour of B. dorsalis on ripe fruit of the same five citrus types that were either damaged or undamaged under no-choice conditions. All tests were conducted in the laboratory. The citrus types tested were Citrus sinensis (L.) Osbeck cv Delta Valencia orange, Citrus sinensis (L.) Osbeck cv Glen Ora Late navel orange, Citrus limon (L) (Burm.f.) cv Eureka lemon, Citrus paradisi (Macfad.) cv Star Ruby grapefruit and Citrus reticulata (Blanco) cv Nadorcott mandarin. Peel physical properties and essential oil composition were determined for each citrus type and stage. Oviposition propensity of B. dorsalis was significantly greater on damaged citrus but was not correlated with fruit diameter, peel thickness, oil gland density or oil gland size. A total of 45 aromatic compounds were found to be significant between the five cultivars investigated, and 6 of 11 compounds were significantly associated with over-ripe fruits. Bactrocera dorsalis spent a significantly greater proportion of time ovipositing in damaged citrus and showed higher aggression when oviposition occurred in undamaged citrus. These results suggest that the removal of damaged and fallen fruit is important for controlling this pest in citrus orchards.

Frugivorous tephritid (Diptera: Tephritidae) females compete over access to fruit for oviposition through aggressive interactions. These aggressive displays are for oviposition site maintenance to reduce the probability of subsequent larval competition. While female aggressive behaviours have been described for several frugivorous tephritid species, studies quantifying behavioural frequencies and sequences and examining how quality of the host fruit might modify the intensity of aggressive behaviours are minimal or absent. We used behavioural analysis software of video playback to describe and quantify antagonistic behaviours between pairs of Bactrocera tryoni females and measured changes in the frequency of behaviours when females were defending three fruit types known to vary in their quality for offspring development. Seven behaviours were identified as part of competitive contests between B. tryoni females, which were not performed in any regular order or with any obvious escalation in the intensity of an aggressive display. Crabbing, [wing] supination and pushing were the most common behaviours, constituting 78% of all observed aggressive behaviours. Increasing fruit quality resulted in aggressive behaviours happening significantly sooner and more often. Our results are similar to previous studies in the types of behaviours exhibited by female frugivorous tephritids but are contrary to other studies in that no sequential pattern or escalation of behaviours was documented. Increased female investment in defence of higher quality hosts aligns with theoretical predictions but has not been previously tested.

The largest diversity in the world of subterranean diving beetles (Dytiscidae) has been discovered in underground waters of the Australian arid zone. The majority of species are from the Dytiscidae genera Limbodessus Guignot, 1939 (Bidessini) and Paroster Sharp, 1882 (Hydroporini) and are distributed within two major regions: calcrete islands of central Western Australia and the Ngalia Basin of the Northern Territory. Here, we use an integrative approach based on morphological and molecular analyses to describe Ngaliadessus humphreysi gen. et sp. nov. Watts & Villastrigo representing a new genus and species of stygobiotic Bidessini collected from a single well in the Ngalia Basin. Phylogenetic analyses using whole mitochondrial genome, Histone 3 and 18S rRNA data, representing a comprehensive coverage of Bidessini genera, support the distinction of the genus and species as a separate evolutionary lineage sister to the Australasian genus Limbodessus and the widely distributed genus Allodessus Guignot, 1953. Our study further confirms that the Ngalia Basin, containing 13 subterranean dytiscid species from four distinct genera, is one of the most speciose areas within the world's most diverse hotspot of subterranean diving beetles.

Dolichostylus gen. nov., a new genus of Portanini, is described, and illustrated, based on two new species: Dolichostylus amazonicus gen. et sp. nov. from Brazil and Ecuador and Dolichostylus zahniseri gen. et sp. nov. from Ecuador. The new genus differs from other portanine genera in having the crown short and rounded, forewing without m-cu2 vein, connective H-shaped, style very long and slender, aedeagus with pair of elongate caudoventral processes, female sternite VII longer than wide and first valvula of ovipositor without a distinctly expanded area.

No abstract is available for this article.

A new monotypic genus in the ‘Archeuptychia clade’ Xikrin Barbosa, Freitas, Siewert & Marín gen. nov. (Nymphalidae: Satyrinae: Euptychiina) is described to accommodate a new species, Xikrin ueharapradoi Freitas & Barbosa gen. et sp. nov., in the highly diverse Satyrinae subtribe Euptychiina, based mainly on molecular data. To date, this species is known only from the region of Carajás, in the eastern Amazon rainforest. The phylogenetic relationship and taxonomy of this new taxon are discussed.

Due to ongoing climate change and the spread of invasive pests, understanding and predicting climatic suitability for invasive insect species has shown growing demand from government and industry biosecurity managers. The invasive pest Bactericera cockerelli, (Šulc) (Hemiptera: Triozidae), commonly known as tomato potato psyllid (TPP), is native to North America and has recently invaded Australasia. TPP is also the vector of the bacterial plant pathogen Candidatus Liberibacter solanacearum (CLso), which has caused severe economic losses for potato growers worldwide. We used the niche modelling software CLIMEX to predict the potential geographical distribution of TPP in Australasia and worldwide under current and future climatic scenarios. Our model prediction of the current climate conditions closely agrees with all the known distributions of TPP. In its native range (North America), TPP is predicted to expand its current geographical range in semi-arid, temperate, and continental climates. Within Australia, along with the known occurrence of TPP in Western Australia, potential expansion into South Australia, Victoria, New South Wales and Queensland is predicted. The predicted distribution closely matches all the known records with higher climatic suitability in New Zealand. Globally, the model projected that the pest-free countries in Europe and East Asia are climatically more suitable for TPP. Predictions under the future climate change scenarios (A1B, CSIRO Mk 3.0 for 2090) showed a significant reduction of the known geographical range of TPP with a possible expansion towards higher latitudes. Areas in North America and Australia are projected to be less climatically suitable for the survival of TPP in future climates. However, our model suggested that Europe and New Zealand will remain unchanged or will become more favourable in the future. These CLIMEX projections for current and future climatic distribution provide valuable information for existing and future biosecurity preparedness and management programmes, which may prove helpful in risk assessments and identifying potential areas that are likely to be susceptible to a TPP invasion.

Parasitoids are among the main natural enemies of crop pests. Copidosoma truncatellum (Hymenoptera: Encyrtidae) is a parasitoid of Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae: Plusiinae), which is an important pest of soybean, bean, cotton, sunflower, tomato and potato. Copidosoma are parasitoids of lepidopteran egg-larva, especially those of the subfamily Plusiinae. The embryonic development of the Copidosoma parasitoid begins in the lepidopteran egg, and this development extends to the beginning of the host larval stage of the parasitized lepidopteran. However, the rate of parasitism is a complex ecological relationship affected by climatic elements and age of the host. Thus, the present study aimed to investigate the ecology and host manipulation exerted by the C. truncatellum parasitoid on C. includens. The research was conducted in bean crops (Phaseolus vulgaris) over 2 years. The highest rates of parasitism were observed in crops in March in both years, when it was observed that about 40% of the individuals of C. includens were parasitized by C. truncatellum. In hot seasons and with less rainfall, parasitism is greater. The age of C. includens eggs (up to 3 days) did not affect C. truncatellum parasitism. The parasitized C. includens egg and caterpillar stages, which had their durations extended, showed the parasitized C. includens caterpillars presented higher leaf consumption. Additionally, this study was conducted in the field, which makes its results representative of natural conditions. Therefore, in warm and dry seasons, more significant parasitism of C. includens by C. truncatellum is expected. Parasitism increases the duration of the stages of lepidopterans and increases food consumption by its larvae.

The trade and keeping of exotic pets has serious implications for both biosecurity and biodiversity conservation. In Australia, the online trade of live invertebrates is an understudied and unregulated issue, with almost non-existent monitoring. It is uncertain what species are being traded, whether they are being identified correctly, and how they are being sourced (i.e., captive bred or wild harvested, native, or alien). Consequently, potential invasion risks and conservation concerns remain unknown. Here, we explored the online trade of terrestrial invertebrates in Australia across a range of publicly available e-commerce platforms. We detected 264 species of invertebrate traded, from 71 families and 168 genera over 12 months. The native Extatosoma tiaratum (giant prickly stick insect) was the most traded species, while the most popular families were Phasmatidae (stick insects), Formicidae (ants) and Theraphosidae (tarantulas). Three species are known to be invasive in Australia, while 87% of species traded were native. The conservation status of almost of the species (92%) listed in the invertebrate trade has not been evaluated. Exploring socio-demographic relationships, we found that human population density was positively correlated with the location of invertebrate sellers. Further, we found the classifieds website had lower prices in contrast to traditional online pet-stores (median of c. A$7 less). Finally, we did not observe a saturation in the number of species traded in our one-year study, exemplifying the need for large scale monitoring and risk assessments for Australia's online terrestrial invertebrate trade. We recommend continued surveillance of live invertebrate trade on e-commerce sites. Substantial changes to legislation and monitoring methods are required at a national level to control the vast number of invertebrates traded across the country, and to minimise the future risks of the invertebrate trade.