Austral Entomology最新文献

No abstract is available for this article.

Since its accidental introduction into New Zealand in 1916, the invasive eucalypt leaf beetle Paropsis charybdis remains a pest of economic significance to Eucalyptus forestry. For this reason, the braconid parasitoid Eadya daenerys has been approved for release as a classical biological control agent. To aid in field monitoring using hand netting of biocontrol releases and laboratory rearing protocols, the flight activity over 6 a year field research program of E. daenerys and the relationships between the parasitoid and the size of its beetle hosts were evaluated in the country of origin. Wasps were observed flying over 32 days from mid-November to mid-December in Tasmania. E. daenerys was found to exhibit a morning-based scramble competition mating system. Females flying in the early morning had lower mature egg loads (134.2 ± 27.6) than at other times of the day. In the first half of the season, male flight was most often seen in the early morning, whereas in the second half of the season, there was a 4.5-fold decrease in any wasps flying. Female flight activity significantly increased to 70% female in the evening hours from 5:00 pm to 8:00 pm, which by the second half of the season was almost exclusively female. Wasps were caught flying across a wide range of air temperatures (10.7–23.8°C), humidity and light levels, but even light winds reduced flight when average wind speed exceeded 0.27 m/s for males and 0.73 m/s for females. Beetle prepupal weight was a predictor of E. daenerys parasitism success with mean beetle prepupal weights significantly higher for stung but unsuccessfully parasitised larva (62.09 mg) than those successfully parasitised (52.94 mg). The chance of an emerged wasp larva spinning a pupal cocoon was found to increase by 5% with every 1-mg increase in its beetle prepupal weight. Heavier beetle prepupae produced bigger parasitoids. Field-collected adult E. daenerys had larger (12%) head capsule widths (mean of 1.42 mm) than those reared in the laboratory (mean of 1.27 mm), suggesting that improving host nutrition and laboratory rearing conditions for increasing host size may help optimise E. daenerys rearing success.

Sonchus oleraceus is an annual species native to Eurasia and Northern Africa that has become a major weed of cultivated fields and ruderal areas in Australia. Populations are difficult to manage in cropping systems because of the development of resistance to common herbicides. Biological control is being investigated as an additional tactic for managing the weed. A literature review was conducted to identify the phytophagous arthropod species already associated with the species in Australia to guide such a biological control programme. To identify opportunities for biological control agents to aid in management, we undertook field surveys across Queensland and South Australia in different environments. We also investigated factors that may influence their performance in Australia. Both the literature review and field surveys identified 21 arthropod species associated with S. oleraceus in Australia, most of them being generalist species and pests of exotic origin. Capitula were the most damaged plant part while stems were relatively free from insects, except aphids. The field surveys recorded an unexpected new interaction between S. oleraceus and the gall midge, Contarinia jongi (Diptera: Cecidomyiidae). This association was surprising as the midge, only known to develop on Alstroemeria (Liliales: Alstroemeriaceae), a very distant relative to S. oleraceus (Asterales: Asteraceae), was reported in Australia only a few years ago under greenhouse conditions. The midge and the moth Eublemma cochylioides (Lepidoptera: Erebidae) were the two species that occurred most frequently in developing flower head samples. We considered their infestation rate as a proxy of herbivory and tested whether the environment surrounding the plant may influence herbivory. Both E. cochylioides and C. jongi showed the highest infestations in ruderal sites compared with the sites located in conventional farming areas. We discuss the implications of our results in the context of selecting and releasing candidates for the biological control of the weed, especially in agricultural landscapes.

The wheat sheath miner, Cerodontha australis, is widespread and abundant in New Zealand and also occurs in eastern Australia. Adult and larval C. australis feed on cereals and grasses, including the economically important perennial ryegrass, Lolium perenne. There is little literature about C. australis, and much of the early work may relate to other species due to its initial misidentification. Morphology-based identification can be challenging, and the absence of online barcode sequences from voucher specimens for C. australis has precluded diagnosis using molecular techniques. In this study, two individual adult leafminers collected from L. perenne plants in New Zealand were confirmed as C. australis morphologically. One has been retained as a voucher specimen and its mitochondrial barcode sequence submitted to online databases. Comparison with adult and larval specimens previously sequenced by the authors confirmed they were also C. australis. Molecular identification of 20 hymenopteran pupal endoparasitoids, and a subset of the puparia they emerged from, revealed Trichopria sp. (Diapriidae), Eupelmus messene (Eupelmidae) and three haplotypes (or closely related species) of Eulophidae. Sequences for all wasps were submitted to GenBank. All the puparia were visually identified as C. australis, and a subset that included a host pupa of each identified endoparasitoid species were confirmed as C. australis based on comparison with our barcode sequence. This work will aid future studies on C. australis and has allowed identification of unidentified sequences on public databases formerly submitted by other New Zealand researchers. It also provides new records of association between C. australis and its pupal endoparasitoids. More broadly, our study provides an example of the importance of authoritative morphological identification of specimens alongside molecular identification, and highlights the challenges in identifying species for which this has not been done.

Taxonomic review of the monotypic Australian endemic lycaenid genus Cyprotides Tite, 1963, based on comparative evidence of adult and juvenile morphology and biology, indicates that it comprises three allopatric and ecologically distinct species: C. pallescens Tite, 1963 stat. rev., C. cyprotus (Olliff, 1886) and C. maculosus sp. nov. Cyprotides cyprotus is considered to comprise three subspecies: C. cyprotus cyprotus (Olliff, 1886) in the Sydney Sandstone region; C. cyprotus lucidus ssp. nov. in the semi-arid zone of inland central New South Wales, north-western Victoria, South Australia, and south-western Western Australia; and C. cyprotus aridus ssp. nov. in the arid zone of southern Northern Territory and Western Australia. In contrast, C. maculosus sp. nov. appears to be a narrow-range endemic, restricted to subalpine areas in south-eastern Australia (~1100–1500 m asl). Information on the distribution, ecology and biology is reviewed and summarised for each of these five taxa, with additional data provided on the habitat and conservation status of C. maculosus sp. nov., which is considered to be Endangered under IUCN Red List Criteria. All three species appear to be characterised by predominantly univoltine life cycles but with variable pupal diapause that may last up to 2–3 years, larval polymorphism, facultative associations with ants, pupal stridulation and rapid larval development involving only four instars. It is hypothesised that speciation within this genus has occurred recently, driven by reinforcement following secondary contact, leading to pre-mating isolation and character displacement, resulting in divergent phenotypes.

The Bag-shelter moth Ochrogaster lunifer (Lepidoptera: Notodontidae: Thaumetopoeinae) is an endemic species of medical and veterinary importance that occurs throughout Australia. The gregarious species is variable with four phylogenetic clades recently identified. One clade comprises trunk-nesters restricted to one host: the Moreton Bay Ash, Corymbia tessellaris (Myrtaceae). Here, we describe aspects of the biology and ecology of this distinctive nesting form dupped the ‘tree-hugger’ due to its flattish, thick silk nests that hug the trunk and larger branches. The form is univoltine; egg masses are laid in spring and the gregarious larvae develop through seven instars until the mature larvae stop feeding in autumn and later leave the nest (in a procession). The larvae over-winter in the ground as pre-pupae in a loose cocoon of silk. Pupation occurs in late winter and adults emerge in spring. Forty-six per cent of monitored egg masses succeeded in developing through the lifecycle. Tachinids were common parasites of older larvae. Tree-hugger nests provided some insulation against summer heat during the mornings, but the physical characteristics of the nests and tree trunks and the average southern orientation of the nests likely protect larvae against extreme heat. The tree-hugger form of O. lunifer appears morphologically similar to the more ubiquitous ground-nesting form, but there are differences in the colour of egg masses and adults, and in the behaviour and ecology of the larvae and adults. This information adds to the body of evidence supporting the definition of separate species within what is currently known as O. lunifer.

Nothepyris Evans, 1973 is revised. Six species are recognised, two being previously described species, Nothepyris brasiliensis Evans, 1973 and Nothepyris pretiosus Colombo & Azevedo, 2019, and four species described and illustrated as new, Nothepyris beedrill sp. nov., Nothepyris combee sp. nov., Nothepyris durant sp. nov. and Nothepyris vespiquen sp. nov. The species Nothepyris sulcatus (Azevedo, 1999) syn. nov. is proposed as a junior synonym of Nothepyris brasiliensis. For the first time, males of this genus are described, and the morphology of the male genitalia is compared and discussed with other Scleroderminae. An updated taxonomic key to all species for both sexes is presented.

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.