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The Bag‐shelter moth, Ochrogaster lunifer (Lepidoptera: Notodontidae), is an Australian endemic species of Thaumetopoeinae with a univoltine life cycle and gregarious, herbivorous larvae. It is variable throughout its range across the continent, most noticeably by the species of host tree used and nest‐building behaviour. It has long been considered a species complex by some taxonomists, and the lack of gene flow between populations of ground‐nesters and above‐ground nesters at the same sites provides strong evidence for at least two species. We tested the specificity of host use and nesting behaviour of ground‐nesting and trunk‐nesting forms of O. lunifer by transplanting field‐collected egg masses to the other form's host, either in their natural position or in the position used by the other form. At the study site, ground‐nesting and trunk‐nesting (tree‐hugger) O. lunifer coexist. Ground‐nesting larvae are found on Acacia spp., and egg masses are laid at the base of host tree trunks where nests develop whereas tree‐hugger larvae are found on Blakella tessellaris, egg masses are laid in the outer canopy, and nests develop on the trunk or large branches. Of the 47 egg masses of O. lunifer transplanted to the unnatural host, only one cohort of tree‐hugger larvae developed through to adult moths. Placing an egg mass in its unnatural position on its natural host did not prevent the larvae from developing and successfully establishing nests for either nesting‐form, although all the ground‐nesters moved position (from the canopy to the ground) and the tree‐huggers mostly did not (from the ground to the canopy). Only the tree‐hugger form of O. lunifer developed a viable nest on the unnatural host species, established a nest at the unnatural oviposition site, and shared that nest with larvae of the other nesting‐form, suggesting tree‐hugger larvae are somewhat plastic in their behaviour and ecology. Our findings add to previous studies indicating that Acacia is likely the ancestral host of O. lunifer though large areas of its range remain unstudied. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Details of feeding behaviour of Australian sawfly species on eucalypt hosts are not well known. In this study, we report new findings on two pergid sawflies, Lophyrotoma interrupta and an unidentified species of Lophyrotoma, after observing larvae feed. We confirmed both daily and nightly feeding regimes, with L. interrupta and Lophyrotoma sp. engaged in feeding‐related activities 92.2% and 67.0% of the time, respectively. A colony sometimes splits into subcolonies as a leaf depletes; individuals leave singly and explore surrounding leaves before joining the rest of the colony feeding on the new leaf. As a specific feeding behaviour, the larvae of both species cut midveins on surrounding leaves in one of several ways before and during feeding. Larvae used pre‐processed cut leaves at a ratio ranging from 0.64 to 0.88 of the whole leaves eaten. Of the leaves cut prior to feeding, approximately half were not consumed, whereas the remaining were consumed 2 days after cutting (median time). We observed a decreasing trend of further cuttings when the proportion of damaged leaves in the surrounding area was increased. Feeding of Lophyrotoma sp. followed a clear pattern: Usually, the last individual remaining on the leaf severed the leaf petiole as it left. This petiole snipping occurred in over half the leaves that larvae had used; however, this behaviour was not observed in L. interrupta. [ABSTRACT FROM AUTHOR]

Helicoverpa armigera is intensively researched in laboratory settings, yet developmental rates can vary considerably even under controlled conditions. Here, dietary choice and light spectra were tested as possible factors influencing this variability, a range of fitness indicators were collected and dietary choice behaviour in early instars was observed. We show that early instars of H. armigera exhibited self‐selection of nutrient intake, a novel finding. Larvae given a choice between two artificial diets varying in macronutrient ratios were heavier, exhibited a higher relative growth rate, shorter developmental time and longer eclosion time compared with larvae reared on a single diet. Wing size relative to body mass was higher for larvae on extreme no choice treatments and smallest for those on the choice diets, indicating a potential adaptation to escape poor nutrient landscapes. Light spectra had an effect on the size of pupae, with H. armigera reared under white LED light having larger pupae than those reared under fluorescent white light. Larvae reared under LED light took longer to emerge from pupation. Giving larvae a choice of diets with a range of nutrients may reduce developmental variability rather than assuming that one diets suits all. [ABSTRACT FROM AUTHOR]

For Helicoverpa punctigera (Wallengren), and to a lesser extent Helicoverpa armigera (Hübner), native host plants in non‐cropping regions of inland Australia are believed to be contributors to populations which migrate in spring to infest cropping regions of south‐east Australia, and southwestern Australia. Non‐crop hosts were sampled using sweep nets in 71 survey trips in 19 years between 1987 and 2017 for larvae of H. punctigera and H. armigera, over about 2.4 million km2 in inland Australia. Of 1976 samples, H. punctigera larvae were present in 50.5%, distributed throughout the study area. Larvae were found on 106 host plant species in 24 families, including 61 new host records. H. armigera larvae were found on 33 plant species from eight families, including 14 new host records. However, only 4.3% of samples were positive for this species, and they were mostly in the east of the study area and had fewer larvae than the positive H. punctigera samples. H. punctigera larvae were found in each of six habitats, being, in order of mean numbers per sample: sandy deserts > floodplains > mulga, grasslands and saltbush > stony downs. Host status was determined for both species by plotting relative incidence against relative abundance, and the good hosts for H. punctigera differed between habitats. We discuss the value and limitations of this approach for identifying key hosts in broad scale population dynamics, and primary hosts which may have close co‐evolutionary histories with the insects. [ABSTRACT FROM AUTHOR]

Euploea alcathoe (Godart, [1819]) (Danainae: Danaini) comprises a taxonomic complex, with recent authors recognising one or two species and numerous subspecies throughout its relatively small geographical range. We determined the taxonomic status of populations from northern Australia by integrating data from ecology, larval colour pattern and morphology, adult morphology (wing morphometrics, wing pattern elements and male genitalia) and molecules (mtDNA). We also investigated the broad distribution of phenotypes based on wing pattern maculation throughout mainland New Guinea and its adjacent islands. Available evidence indicates that Euploea eichhorni Staudinger, 1884, stat. rev. from northern Queensland is allopatric and phenotypically and genotypically distinct from E. alcathoe, with 11 phenotypic character state differences in larval pattern and morphology, adult wing pattern and male genitalia, as well as significant differences in wing shape and in frequency distribution of the number of white spots. Genetic data and divergence time estimates based on COI revealed that E. eichhorni and E. alcathoe are reciprocally monophyletic with a mean pairwise divergence of 0.9% and with E. eichhorni comprising only a single unique haplotype. Phylogeographic analysis suggests E. eichhorni diverged as a peripheral isolate from E. alcathoe, most likely during the Late Pleistocene. In the Wet Tropics of northern Queensland, larvae of E. eichhorni specialise on the vine Gymnanthera oblonga (Burm.f.) P.S. Green (Apocynaceae) growing in coastal, broadleaf paperbark swampland, a larval host plant also used by E. alcathoe. A lectotype male of E. eichhorni is designated, with Cooktown, Queensland as the type locality. Euploea alcathoe enastri Fenner, 1991, from the Northern Territory is maintained because it was found to be allopatric, phenotypically distinct, with at least one diagnosable character state (larger number of forewing subapical spots among males), and genetically divergent according to population genetic structure compared with Euploea alcathoe misenus from Torres Strait. Based on our review of E. alcathoe from New Guinea and Torres Strait, we found that populations from at least the southern coastline of New Guinea differed little phenotypically from E. alcathoe misenus; thus, we regard the subspecies Euploea aethiops monaeses Fruhstorfer, 1910, syn. nov. and E. alecto rothschildiana Hulstaert, 1923, syn. nov. as junior synonyms of E. alcathoe misenus Miskin, 1890. [ABSTRACT FROM AUTHOR]

Abstract: Although higher than expected numbers of surviving larvae of Helicoverpa spp. are reported in some Bollgard II cotton fields from time to time, there is no convincing evidence that field resistance has developed. A behavioural component, specifically the avoidance of the toxin, was considered to contribute to larvae surviving on Bacillus thuringiensis (Bt) toxin‐expressing plants. Experiments were conducted with Bt‐susceptible and Bt‐resistant larvae of Helicoverpa armigera to investigate (1) how larval responses to food deprivation might lead to differences in survival and therefore how far neonates could move to find a suitable feeding site and (2) whether larvae that are physiologically susceptible vs. resistant behave differently when feeding on diet with Bt and without Bt toxins. Bt‐susceptible neonates of H. armigera, which were significantly heavier, could survive without food for longer and recover better than Bt‐resistant neonates. Although H. armigera neonates did not shift their behaviour with respect to Bt toxin on artificial diet before their first feeding event, the tendency of Bt‐susceptible larvae to remain on non‐Bt diet and move off Bt diet may allow them to survive in a Bt environment. This behaviour resulted in a higher percentage of survival in situations where a diet choice was offered. [ABSTRACT FROM AUTHOR]

The distribution and abundance of subterranean termites in Brisbane, Australia, has not previously been investigated, despite the sub-tropical climate being favourable for these xylophagous insects which often cause damage to the built environment. Data on the incidence of termite infestations, including taxonomic identity, locality and site of infestation within premises were collected by a large commercial pest management company in metropolitan Brisbane during a ten-year period (1997 - 2006). General Linear Models based on a negative binomial distribution were used to examine the influence of the climatic variables of rainfall and Southern Oscillation Index (SOI), and the demographic variables of premise density and socioeconomic status, on the number of termite infestations found. Two genera of termites dominated: Schedorhinotermes, which was the most abundant both indoors and outdoors, and Coptotermes. That Schedorhinotermes spp. were the major xylophagous subterranean termites recorded is unique in Australian capital cities where Coptotermes spp. usually dominate. The patterns of abundance and distribution of both genera are discussed with respect to their differing biology. SOI, premise density per ha and household income all significantly explained the variation in termite abundance reported across metropolitan Brisbane over the 10 year study. Our results shows the potential for using SOI as a predictor of termite activity. Further study is needed to more accurately correlate the key drivers of termite activity with the incidence of termite infestations in premises. [ABSTRACT FROM AUTHOR]

Insecticide resistance in the common bed bug, C imex lectularius Linnaeus has been suspected in Australia with anecdotal reports of poor product performance. To investigate this possibility, LD50 values were determined via topical application of technical grade permethrin, deltamethrin, bendiocarb, pirimiphos-methyl and imidacloprid serially diluted in acetone to a suspected resistant field-collected strain and a susceptible laboratory strain. All compounds tested against the susceptible strain were efficacious. However, for the field strain, only pirimiphos-methyl and imidacloprid showed high levels of activity. Resistance was confirmed in the field-collected strain to the pyrethroids and bendiocarb, but not to pirimiphos-methyl or imidacloprid. Resistance factors ('resistant' LD50/susceptible LD50) for each compound were: permethrin ≈ 1.235 million, deltamethrin ≈ 370 000, bendiocarb ≈ 250, pirimiphos-methyl = 2.6, imidacloprid = 2.6. Bendiocarb, permethrin and deltamethrin all failed to return greater than 60% mortality at the maximum dose of 100 μg/μ L. This research has significant operational implications for bed bug control and the registration process of new products in Australia. [ABSTRACT FROM AUTHOR]