Holocene population expansion of a tropical bee coincides with early human colonization of Fiji rather than climate change.

There is substantial debate about the relative roles of climate change and human activities on biodiversity and species demographies over the Holocene. In some cases, these two factors can be resolved using fossil data, but for many taxa such data are not available. Inferring historical demographies of taxa has become common, but the methodologies are mostly recent and their shortcomings often unexplored. The bee genus Homalictus is developing into a tractable model system for understanding how native bee populations in tropical islands have responded to past climate change. We greatly expand on previous studies using sequences of the mitochondrial gene COI from 474 specimens and between 171 and 3928 autosomal (DArTSeq) single nucleotide polymorphism loci from 19 specimens of the native Fijian bee, Homalictus fijiensis, to explore its historical demography using coalescent and mismatch analyses. We ask whether past changes in demography were human- or climate-driven, while considering analytical assumptions. We show that inferred changes in population sizes are too recent to be explained by past climate change. Instead we find that a dramatic increase in population size for the main island of Viti Levu coincides with increasing occupation by humans and their modification of the environment. We found no corresponding change in bee population size for another major island, Kadavu, where human populations and agricultural activities have been historically very low. Our analyses indicate that molecular approaches can be used to disentangle the impacts of humans and climate change on a major tropical pollinator and that stringent analytical approaches are required for reliable interpretation of results.

Two new endemic species of emAbantiades/em Herrich-Schäffer (Lepidoptera: Hepialidae) from Kangaroo Island, Australia.

Abantiades penneshawensis Moore Beaver sp. nov. and Abantiades rubrus Moore Beaver sp. nov. are described as new. Both species are endemic to Kangaroo Island, and although both are related to species that occur on the Australian mainland and other islands, they are distinguished from those sister and phenotypically similar species by morphology and mtDNA (COI) barcodes. These two new species raise the number of Abantiades species on Kangaroo Island to six, three being endemic, and 45 species in the genus for the whole of Australia. There are now 13 species of Hepialidae (one undescribed) known from Kangaroo Island and we discuss the potential effects of recent catastrophic fire on some distributions.

Four new species of Splendid Ghost Moths (Lepidoptera: Hepialidae: Aenetus) from Australia and Papua New Guinea.

Four new Aenetus Herrich-Schäffer species are described from northern Australasia; Aenetus simonseni sp. nov. from the top-end of the Northern Territory, Australia, A. maiasinus sp. nov. from the Kimberley region of Western Australia, A. trigonogrammus sp. nov. from south-eastern Queensland, Australia, and A. albadamanteum sp. nov. from eastern Papua New Guinea. Aenetus simonseni sp. nov. and A. maiasinus sp. nov. appear to belong to the tegulatus-group of species (sensu Grehan et al. 2018), A. trigonogrammus sp. nov. is part of the splendens-group of species (sensu Simonsen 2018), while A. albadamanteum sp. nov. shares morphological similarities with A. hampsoni (Joicey Noakes, 1914), A. crameri Viette, 1956, and A. toxopeusi Viette, 1956, from New Guinea, and A. cohici Viette, 1961 from New Caledonia. The four new species are illustrated and compared with superficially similar species in morphology and, for two species, molecular (mtDNA COI gene) sequences.

Description of two new Australian species of Abantiades Herrich-Schäffer (Lepidoptera: Hepialidae) and females of two further species with notes on their biogeography.

Abantiades cephalocorvus sp. nov. and Abantiades tembyi sp. nov. are described, along with the previously undescribed females of A. macropusinsulariae Simonsen, 2018 and A. pallida Simonsen, 2018. All of these species belong to a triforked Abantiades Herrich-Schäffer clade that is loosely centred around the Nullarbor and other arid regions of Australia. We explore DNA barcodes (mtDNA COI gene) from these and other Abantiades and discuss their significance for species recognition. The species distributions are entirely or largely allopatric and we discuss their origins from a widespread common ancestor that was likely distributed over inland and coastal regions in the mid- to late-Mesozoic before the onset of desertification. Notes on new distributional data for all of the known species in this clade are included.

Four new tri-forked species of the Australian genus Abantiades Herrich-Schäffer (Lepidoptera: Hepialidae) from the "dark obscura clade".

A distinct group of Abantiades Herrich-Schäffer species is here confirmed as a valid clade that we refer to as the "dark obscura clade" supported by morphological and mtDNA evidence. The clade is the sister group of A. obscura Simonsen of north-western Australia and comprises four new species: Abantiades centralia sp. nov., A. kayi sp. nov., A. zonatriticum sp. nov., and A. hutchinsoni sp. nov. These species together with A. obscura, are reciprocally allopatric and have a combined distribution spanning much of the western half of Australia and this distribution is consistent with their each differentiating locally from a widespread ancestor. The four new species raise the diversity of Abantiades to 42 species. [Zoobank urn:lsid:zoobank.org:pub:C05458D1-0D34-4432-8EC4-D031ED6B7BEF].

Three new ghost moths of the genus Oxycanus Walker, 1856 from Australia (Lepidoptera: Hepialidae).

Three new species of ghost moth, Oxycanus ephemerous sp. nov., O. flavoplumosus sp. nov., and O. petalous sp. nov. are described from South Australia, New South Wales, and south-west Western Australia, respectively. We illustrate these species and compare morphological and molecular (mtDNA COI gene) characters with similar Oxycanus Walker, 1856 species from Australia. Comparative images of Oxycanus subvaria (Walker, 1856), O. byrsa (Pfitzner, 1933), and O. determinata (Walker, 1856) are figured. The type material of the three new species are held in the Australian National Insect Collection, Canberra, the Western Australian Museum, Perth, and in the South Australian Museum, Adelaide. The type specimens of Oxycanus hildae Tindale, 1964 syn. n. were also examined and the taxon is here considered synonymous with O. subvaria. Concerns are raised about the conservation status of all three new species due to few or localised distribution records.

Distribution and diversity of soil microfauna from East Antarctica: assessing the link between biotic and abiotic factors.

Terrestrial life in Antarctica has been described as some of the simplest on the planet, and mainly confined to soil microfaunal communities. Studies have suggested that the lack of diversity is due to extreme environmental conditions and thought to be driven by abiotic factors. In this study we investigated soil microfauna composition, abundance, and distribution in East Antarctica, and assessed correlations with soil geochemistry and environmental variables. We examined 109 soil samples from a wide range of ice-free habitats, spanning 2000 km from Framnes Mountains to Bailey Peninsula. Microfauna across all samples were patchily distributed, from complete absence of invertebrates to over 1600 specimens/gram of dry weight of soil (gdw), with highest microfauna abundance observed in samples with visible vegetation. Bdelloid rotifers were on average the most widespread found in 87% of sampled sites and the most abundant (44 specimens/gdw). Tardigrades occurred in 57% of the sampled sites with an abundance of 12 specimens/gdw. Nematodes occurred in 71% of samples with a total abundance of 3 specimens/gdw. Ciliates and mites were rarely found in soil samples, with an average abundance of 1.3 and 0.04 specimens/gdw, respectively. We found that microfaunal composition and abundance were mostly correlated with the soil geochemical parameters; phosphorus, NO3 (-) and salinity, and likely to be the result of soil properties and historic landscape formation and alteration, rather than the geographic region they were sampled from. Studies focusing on Antarctic biodiversity must take into account soil geochemical and environmental factors that influence population and species heterogeneity.