Austral Entomology最新文献

No abstract is available for this article.

Eunanus Ohaus, 1909 has so far been known exclusively from Argentina and Paraguay, with only two described species: E. murinus Ohaus, 1909 and E. podtiaguini Gutiérrez, 1951. Here, the genus is revised and redefined, and two new species are described from Brazil: Eunanus kozlovi sp. nov., from Mato Grosso do Sul state, and Eunanus valmorbidai sp. nov., from Rio Grande do Sul state. Furthermore, Leucothyreus beckeri (Martínez, 1964) is transferred to the genus under the new combination Eunanus beckeri (Martínez, 1964) comb. nov. The lectotype of E. murinus Ohaus, 1909 is designated, and an identification key to all the species and a distribution map are provided.

Odd-clawed spiders (Gradungulinae), which are considered to be ‘living fossils’, are a faunal element of the mesic forests of eastern Australia and the South Island of New Zealand. To date, 16 species in seven genera are known, with most being highly endemic and hard to find, explaining their scarcity in collections worldwide. Particularly noteworthy is the Australian genus Progradungula that includes only two relict species from eastern Australia (Progradungula carraiensis from the Carrai limestone caves in northern New South Wales and Progradungula otwayensis from Nothofagus rainforests in the Otway Range, southern Victoria) and are known from only a handful of adult specimens. Both species are large nocturnal predators with a rather cryptic lifestyle, which construct unique ladder-like catching webs composed of non-combed and combed cribellate silk with exceptional properties. Here, we describe a new relict species, Progradungula barringtonensis Michalik & Smith, sp. nov., from isolated Nothofagus forest patches in Barrington Tops National Park (NSW, Australia). The male of this species is significantly larger than those of P. carraiensis and P. otwayensis and exhibits characteristics of the male genitalia of both species. The webs are similar to those of the other Progradungula species. Field observations revealed that the catching ladder had few looping segments, similar to P. otwayensis, but an immature in captivity constructed webs with more looping segments, similar to P. carraiensis, supporting the previously proposed hypothesis that food availability may explain the plasticity of the catching ladder structure.

Aphids are a major pest of cropping systems throughout the world. In most cases, crop aphids are controlled with broad-spectrum insecticides; although generally very effective at preventing yield loss, this approach risks non-target damage to beneficial organisms. In the last 20 years, a number of selective insecticides have become available to control aphids while minimising harm to other arthropods. Previous studies have found that two such insecticides, flonicamid and afidopyropen, cause only low-level acute mortality impacts on aphid parasitoids in Australian grain crops. However, little research has examined the sub-lethal effects of these chemicals, which could induce various physiological changes that impact pest control. We hypothesised that both flonicamid and afidopyropen have negative effects that extend beyond the immediate acute mortality previously published. To test this hypothesis, we undertook a series of experiments to determine the effects of flonicamid and afidopyropen, along with the synthetic pyrethroid gamma-cyhalothrin, on aphid parasitism (mummification) rate, emergence rate of the next generation and the next generation sex ratio in three important aphid parasitoids, Aphidius colemani (Viereck), Diaeretiella rapae (M'Intosh) and Aphelinus abdominalis (Dalman). Analogous with previous research, our acute toxicity bioassays showed that all three insecticides had low (<30%) mortality impacts. Although sub-lethal impacts could not be assessed for D. rapae due to the low level of aphid parasitism by that species, our findings showed negative impacts on fecundity in surviving A. abdominalis and A. colemani. Of particular note is the increase in International Organisation for Biological Control ratings to moderate (30%–80% mortality and/or reproductive reduction) when mortality and reduced fecundity effects were combined to determine overall fitness impacts. Gamma-cyhalothrin typically resulted in higher negative impacts on A. abdominalis and A. colemani (compared with flonicamid and afidopyropen); however, quite surprisingly, these impacts were not rated as highly toxic. Taken together, our results suggest that, even when sub-lethal impacts are considered, flonicamid and afidopyropen are useful tools for farmers targeting aphid populations while minimising the non-target impacts on parasitoids. We recommend semi-field and/or field trials to further assess the impacts of these insecticides on aphid parasitoid populations.

The oviparous blow fly Calliphora vicina has shown potential as a managed pollinator to support honeybee (Apis mellifera) usage in Australian horticulture. A series of three laboratory-based studies reared newly hatched larvae of C. vicina on meatmeal with varying amounts of either whole egg powder, whole eggs (including shells), bran flakes, brewer's yeast, fish paste or milk powder. The objective was to determine the best larval media for quick and efficient production of adult flies in a mass-rearing environment. Pure meatmeal or meatmeal with only brewer's yeast added were the least productive media. Larvae fed meatmeal with either 10% or 20% whole dried egg powder had the fastest development to pupae, the highest pupation rate, the heaviest pupae and the highest subsequent adult eclosion. Larval media containing fish paste had the highest survival through to adult emergence (>85%) of all the media treatments, which suggests that this ingredient is of value when mass rearing C. vicina. In addition, newly hatched larvae (n = 50) were reared on varying amounts of media (i.e., 4, 2, 1, 0.5, 0.25 and 0.125 g per larvae) to determine the minimum amount of media required to produce adults. Reductions in media per larvae resulted in smaller pupae and adults that emerged with no subsequent reduction in adult eclosion, indicating the adaptability of this fly to food deprivation. Replacing whole egg powder with whole eggs reduces the costs of rearing C. vicina larvae significantly. In order to rear 1 million adult C. vicina, these studies showed that 0.5 g of media per larvae is sufficient to produce high numbers of pupae with >95% adult eclosion. Although larval development and pupation are optimal on media containing whole egg powder, its recent rapid rise in costs makes it far less economical compared with the use of discarded whole eggs from egg producers. Sourcing of seafood waste could also reduce media costs and improve production of C. vicina. The costs of each media required to realise 1 million adult C. vicina are between $540 and $1900 depending on the media ingredients.

No abstract is available for this article.

Eurema brigitta (Stoll, 1780) is one of the few butterfly species distributed in most of the Old World tropics. In 2017, we documented its occurrence in Socotra, a UNESCO World Heritage Site. Now, we clarify the origin of this specimen and further describe a phylogeographic pattern of this species by comparing Afrotropical, Malagasy and Oriental-Australian populations using the mitochondrial cytochrome c oxidase subunit I marker. We found a deep split between the Afrotropical and Oriental-Australian populations of this taxon, which are separated by the Indian Ocean and dry eremic habitats on the northern coasts. A less deep but significant split also exists between E. b. brigitta (Stoll, 1780) from mainland Africa and E. b. pulchella (Boisduval, 1833) from Madagascar and surrounding islands. The individual from Socotra clearly originates from Africa. In addition, in accordance with the genetic pattern and the known morphological evidence, we propose to transfer the Oriental-Australian populations into a separate species, Eurema drona (Horsfield, 1829) reinst. stat.

The Australian endemic dung beetle Labroma Sharp, 1873 is redescribed and revised. Five species are recognised, two new: L. horrens Sharp, 1873, L. monteithi sp. nov., L. toonumbar sp. nov., L. tuberculata (Waterhouse, 1874) and L. umbratilis Matthews, 1974. The genus, hitherto only known from southwest Western Australia, is newly recorded from New South Wales. Systematics of the genus and conservation status of its species are discussed.

Australian ports are continuously exposed to exotic and invasive mite and insect species associated with imported fresh produce. Much effort is focused on preventing the exotic species from entering Australia by product fumigation or destruction in a timely manner. However, quarantine intercepts of invasive species may contain unwanted resistance to pesticides or carry viruses that can undermine Australian agricultural sustainability. We examined pesticide resistance status in 1275 Tetranychus urticae samples from quarantine intercepts from the Department of Agriculture, Fisheries and Forestry originating from some 29 countries spread over 6 main continents (Africa [4], Asia [12], Europe [3], North America [2], Oceania [4] and South America [4]). We used a high-throughput multiamplicon sequencing platform to screen major target-site mutations that cause acaricide resistance in T. urticae. These included G119S, A201S, T280A, G328A and F331Y (Ace-1) associated with mode of action (MoA) 1 insecticide (organophosphates and carbamates); M918, L925I, L1014F and F1538I (VGSC) associated with MoA 3 insecticide (pyrethroids); G314D (GluCl1) associated with MoA 6 insecticide (avermectins and milbemycins); and finally, H92R (PSST) associated with MoA 21 insecticide (fenpyroximate, pyridaben and tebufenpyrad). The results revealed that four known mutations (G119S, T280A, G328A and F331W) were abundant in the quarantine samples including those from Norfolk Island and New Zealand. The mutations L1024V, F1538I and L925V (VGSC) associated with pyrethroid resistance were widespread through many samples, but the super Kdr mutation M918 was not detected. Similarly, H92R (PSST) that causes resistance to fenpyroximate, pyridaben and tebufenpyrad was found in most of the T. urticae intercept samples. We conclude that resistance alleles entering Australia through quarantine intercepts are common, suggesting that unwanted or rare alleles could enter Australia via this route. However, exotic quarantine breaches carrying such alleles remain of most serious concern.