Antarctic Entomology

An outsider on the Antarctic Peninsula: A new record of the non-native moth Plodia interpunctella (Lepidoptera: Pyralidae)

We report the first record of the microlepidopteran Plodia interpunctella beyond the South Shetland Islands at the Chilean Yelcho scientific station (64°52'33.1428″ S; 63°35'1.9572″ W), Doumer Island, close to the west coast of the Antarctic Peninsula. It is notable that P. interpunctella, a globally distributed stored product pest species, exhibits a remarkable capacity for prolonged viability within food storage facilities. The dual challenges of food transportation and storage in the context of Antarctica's challenging operational conditions may have facilitated P. interpunctella's initial arrival to the Antarctic region. Non-perishable food items, such as grains, flour and rice, provide practical options for the bulk food transportation and storage required in the long-term operation of Antarctic research stations. The presence of P. interpunctella in Antarctica, even if restricted to synanthropic environments within buildings, is a clear threat to Antarctic biodiversity, not only through being an invasive species itself but also as a potential vector for other non-native species (bacteria, acari, between others.), which could carry diseases to the native species.

Molecular evidence for multiple origins and high genetic differentiation of non-native winter crane fly, Trichocera maculipennis (Diptera: Trichoceridae), in the maritime Antarctic

Native biodiversity and ecosystems of Antarctica safeguarded from biological invasion face recent threats from non-native species, accelerated by increasing human activities and climate changes. Over two decades ago, the winter crane fly, Trichocera maculipennis, was first detected on King George Island. It has now successfully colonized several research stations across King George Island. To understand the origin, genetic diversity, and population structure of this Holarctic species, we conducted mitochondrial DNA cytochrome c oxidase subunit I (COI) sequence analysis across both its native and invasive ranges. In parallel, we performed microsatellite loci analysis within the invasive ranges, utilizing 12 polymorphic microsatellite markers. Furthermore, we compared body sizes among adult males and females collected from three different locations of King George Island. Our COI sequence analysis exhibited two different lineages present on King George Island. Lineage I was linked to Arctic Svalbard and Polish cave populations and Lineage II was related to Canadian Terra Nova National Park populations, implying multiple origins. Microsatellite analysis further exhibited high levels of genetic diversity and significant levels of genetic differentiation among invasive populations. Body sizes of adult T. maculipennis were significantly different among invasive populations but were not attributed to genetics. This significant genetic diversity likely facilitated the rapid colonization and establishment of T. maculipennis on King George Island, contributing to their successful invasion. Molecular analysis results revealed a substantial amount of genetic variation within invasive populations, which can serve as management units for invasive species control. Furthermore, the genetic markers we developed in the study will be invaluable tools for tracking impending invasion events and the travel routes of new individuals. Taken together, these findings illustrate the highly invasive and adaptable characteristics of T. maculipennis. Therefore, immediate action is necessary to mitigate their ongoing invasion and facilitate their eradication.

Polar lake microbiomes have distinct evolutionary histories

Toward the poles, life on land is increasingly dominated by microorganisms, yet the evolutionary origin of polar microbiomes remains poorly understood. Here, we use metabarcoding of Arctic, sub-Antarctic, and Antarctic lacustrine benthic microbial communities to test the hypothesis that high-latitude microbiomes are recruited from a globally dispersing species pool through environmental selection. We demonstrate that taxonomic overlap between the regions is limited within most phyla, even at higher-order taxonomic levels, with unique deep-branching phylogenetic clades being present in each region. We show that local and regional taxon richness and net diversification rate of regionally restricted taxa differ substantially between polar regions in both microeukaryotic and bacterial biota. This suggests that long-term evolutionary divergence resulting from low interhemispheric dispersal and diversification in isolation has been a prominent process shaping present-day polar lake microbiomes. Our findings illuminate the distinctive biogeography of polar lake ecosystems and underscore that conservation efforts should include their unique microbiota.

Increasing temperature-driven changes in life history traits and gene expression of an Antarctic tardigrade species

The Antarctic region has been experiencing some of the planet's strongest climatic changes, including an expected increase of the land temperature. The potential effects of this warming trend will lead ecosystems to a risk of losing biodiversity. Antarctic mosses and lichens host different microbial groups, micro-arthropods and meiofaunal organisms (e.g., tardigrades, rotifers). The eutardigrade Acutuncus antarcticus is considered a model animal to study the effect of increasing temperature due to global warming on Antarctic terrestrial communities. In this study, life history traits and fitness of this species are analyzed by rearing specimens at two different and increasing temperatures (5°C vs. 15°C). Moreover, the first transcriptome analysis on A. antarcticus is performed, exposing adult animals to a gradual increase of temperature (5°C, 10°C, 15°C, and 20°C) to find differentially expressed genes under short- (1 day) and long-term (15 days) heat stress. Acutuncus antarcticus specimens reared at 5°C live longer (maximum life span: 686 days), reach sexual maturity later, lay more eggs (which hatch in longer time and in lower percentage) compared with animals reared at 15°C. The fitness decreases in animals belonging to the second generation at both rearing temperatures. The short-term heat exposure leads to significant changes at transcriptomic level, with 67 differentially expressed genes. Of these, 23 upregulated genes suggest alterations of mitochondrial activity and oxido-reductive processes, and two intrinsically disordered protein genes confirm their role to cope with heat stress. The long-term exposure induces alterations limited to 14 genes, and only one annotated gene is upregulated in response to both heat stresses. The decline in transcriptomic response after a long-term exposure indicates that the changes observed in the short-term are likely due to an acclimation response. Therefore, A. antarcticus could be able to cope with increasing temperature over time, including the future conditions imposed by global climate change.

Revealing the hidden biodiversity of Antarctic and the Magellanic Sub-Antarctic Ecoregion: A comprehensive study of aquatic invertebrates from the BASE Project

Background

Antarctica, its outlying archipelagoes and the Magellanic Subantarctic (MSA) ecoregion are amongst the last true wilderness areas remaining on the planet. Therefore, the publication, citation and peer review of their biodiversity data are essential. The new Millennium Institute Biodiversity of Antarctic and Subantarctic Ecosystems (BASE), a Chilean scientific initiative funded by the National Agency of Research and Innovation, contributes 770 new records of aquatic invertebrates as a point of reference for present-day biodiversity research at these latitudes.

New information

The occurrence dataset presented here has never been released before and is the result of the systematic recording of occurrences of several taxa across the Antarctic, Subantarctic and Magellanic Subantarctic ecoregions. We collected data from marine and freshwater invertebrates across numerous samplings from 2008 to 2023. From the 770 occurrences, we identified 160 taxa, 125 at species level and 35 at the genus level. The database has been registered in the Global Biodiversity Information Facility (GBIF). The publication of this data paper was funded by the Belgian Science Policy Office (BELSPO, contract n°FR/36/AN1/AntaBIS) in the Framework of EU-Lifewatch as a contribution to the SCAR Antarctic biodiversity portal (biodiversity.aq).

Introduced and invasive alien species of Antarctica and the Southern Ocean Islands

Open data on biological invasions are particularly critical in regions that are co-governed and/or where multiple independent parties have responsibility for preventing and controlling invasive alien species. The Antarctic is one such region where, in spite of multiple examples of invasion policy and management success, open, centralised data are not yet available. This dataset provides current and comprehensive information available on the identity, localities, establishment, eradication status, dates of introduction, habitat, and evidence of impact of known introduced and invasive alien species for the terrestrial and freshwater Antarctic and Southern Ocean region. It includes 3066 records for 1204 taxa and 36 individual localities. The evidence indicates that close to half of these species are not having an invasive impact, and that ~ 13% of records are of species considered locally invasive. The data are provided using current biodiversity and invasive alien species data and terminology standards. They provide a baseline for updating and maintaining the foundational knowledge needed to halt the rapidly growing risk of biological invasion in the region.

Survivors and colonizers: Contrasting biogeographic histories reconciled in the Antarctic freshwater copepod Boeckella poppei

Two main hypotheses have been proposed to explain the contemporary distribution of Antarctic terrestrial biota. We assess whether the current distribution of maritime Antarctic populations of the freshwater copepod Boeckella poppei is the result of (1) a post-Last Glacial Maximum (LGM) colonization, or whether (2) the species survived in regional glacial refugia throughout the LGM and earlier glaciations. Using 438 specimens from 34 different sampling sites across Southern South America, South Georgia, South Orkney Islands, South Shetland Islands, and the Antarctic Peninsula, we analyzed mitochondrial and nuclear sequences to uncover patterns of genetic diversity and population structure. We also performed median-joining haplotype network, phylogenetic reconstruction, and divergence time analyses. Finally, we evaluated past demographic changes and historical scenarios using the Approximate Bayesian Computation (ABC) method. Our data support the existence of two clades with different and contrasting biogeographic histories. The first clade has been present in maritime Antarctica since at least the mid-Pleistocene, with the South Orkney Islands the most likely refugial area. The second clade has a broader distribution including southern South America, South Georgia, South Shetland Islands, and the Antarctic Peninsula. The ABC method identified long-distance dispersal (LDD) colonization event(s) from southern South America to South Georgia and the maritime Antarctic after the LGM deglaciation, supporting more recent colonization of Antarctic locations. The current Antarctic and sub-Antarctic distribution of B. poppei is likely derived from two independent biogeographic events. The combination of both (1) post-LGM colonization from southern South America and (2) longer-term persistence in in situ regional refugia throughout glacial periods challenges current understanding of the biogeographic history of Antarctic freshwater biota. Re-colonization of ice-impacted Antarctic areas would have occurred following a LDD and Establishment model, pointing to the existence of possible post-dispersal barriers, despite widely assumed high passive dispersal capacity in freshwater invertebrates.

The rising threat of climate change for arthropods from Earth's cold regions: Taxonomic rather than native status drives species sensitivity

Polar and alpine regions are changing rapidly with global climate change. Yet, the impacts on biodiversity, especially on the invertebrate ectotherms which are dominant in these areas, remain poorly understood. Short-term extreme temperature events, which are growing in frequency, are expected to have profound impacts on high-latitude ectotherms, with native species being less resilient than their alien counterparts. Here, we examined in the laboratory the effects of short periodic exposures to thermal extremes on survival responses of seven native and two non-native invertebrates from the sub-Antarctic Islands. We found that survival of dipterans was significantly reduced under warming exposures, on average having median lethal times (LT50 ) of about 30 days in control conditions, which declined to about 20 days when exposed to daily short-term maxima of 24°C. Conversely, coleopterans were either not, or were less, affected by the climatic scenarios applied, with predicted LT50 as high as 65 days under the warmest condition (daily exposures at 28°C for 2 h). The native spider Myro kerguelensis was characterized by an intermediate sensitivity when subjected to short-term daily heat maxima. Our results unexpectedly revealed a taxonomic influence, with physiological sensitivity to heat differing between higher level taxa, but not between native and non-native species representing the same higher taxon. The survival of a non-native carabid beetle under the experimentally imposed conditions was very high, but similar to that of native beetles, while native and non-native flies also exhibited very similar sensitivity to warming. As dipterans are a major element of diversity of sub-Antarctic, Arctic and other cold ecosystems, such observations suggest that the increased occurrence of extreme, short-term, thermal events could lead to large-scale restructuring of key terrestrial ecosystem components both in ecosystems protected from and those exposed to the additional impacts of biological invasions.

Global Warming Could Magnify Insect-Driven Apparent Competition Between Native and Introduced Host Plants in Sub-Antarctic Islands

Pristine sub-Antarctic islands terrestrial ecosystems, including many endemic species, are highly threatened by human-induced cosmopolitan plant invasion. We propose that native plant suppression could be further facilitated by the subsequent invasion by generalist pest species that could exacerbate their competitive exclusion through the process of apparent competition. By comparing the biological parameters of an invasive aphid species, Myzus ascalonicus, on one native (Acaena magellanica) and one invasive (Senecio vulgaris) plant species, we showed that survival and fecundity were higher and development time lower on the native plant species than on the invasive one. Moreover, comparing the effect of a temperature increase on the population dynamics of M. ascalonicus on the two plants, we showed that the relative profitability of the native species is further amplified by warming. Hence, while pest population doubling time is 28% higher on the invasive plant under current temperature, it would become 40% higher with an increase in temperature of 3°C. Consequently, our findings demonstrate that global warming could exacerbate competitive exclusion of native plants by invasive plants in sub-Antarctic islands by its indirect effect on the apparent competition mediated by generalist phytophagous pests.

Belgica antarctica (Diptera: Chironomidae): A natural model organism for extreme environments

Belgica antarctica (Diptera: Chironomidae), a brachypterous midge endemic to the maritime Antarctic, was first described in 1900. Over more than a century of study, a vast amount of information has been compiled on the species (3 750 000 Google search results as of January 10, 2021), encompassing its ecology and biology, life cycle and reproduction, polytene chromosomes, physiology, biochemistry and, increasingly, omics. In 2014, B. antarctica's genome was sequenced, further boosting research. Certain developmental stages can be cultured successfully in the laboratory. Taken together, this wealth of information allows the species to be viewed as a natural model organism for studies of adaptation and function in extreme environments.

Transcriptomics Integrated With Metabolomics Reveal the Effects of Ultraviolet-B Radiation on Flavonoid Biosynthesis in Antarctic Moss

Bryophytes are the dominant vegetation in the Antarctic continent. They have suffered more unpleasant ultraviolet radiation due to the Antarctic ozone layer destruction. However, it remains unclear about the molecular mechanism of Antarctic moss acclimation to UV-B light. Here, the transcriptomics and metabolomics approaches were conducted to uncover transcriptional and metabolic profiling of the Antarctic moss Leptobryum pyriforme under UV-B radiation. Totally, 67,290 unigenes with N₅₀ length of 2,055 bp were assembled. Of them, 1,594 unigenes were significantly up-regulated and 3353 unigenes were markedly down-regulated under UV-B radiation. These differentially expressed genes (DEGs) involved in UV-B signaling, flavonoid biosynthesis, ROS scavenging, and DNA repair. In addition, a total of 531 metabolites were detected, while flavonoids and anthocyanins accounted for 10.36% of the total compounds. There were 49 upregulated metabolites and 41 downregulated metabolites under UV-B radiation. Flavonoids were the most significantly changed metabolites. qPCR analysis showed that UVR8-COP1-HY5 signaling pathway genes and photolyase genes (i.e., LpUVR3, LpPHR1, and LpDPL) were significantly up-regulated under UV-B light. In addition, the expression levels of JA signaling pathway-related genes (i.e., OPR and JAZ) and flavonoid biosynthesis-related genes were also significantly increased under UV-B radiation. The integrative data analysis showed that UVR8-mediated signaling, jasmonate signaling, flavonoid biosynthesis pathway and DNA repair system might contribute to L. pyriforme acclimating to UV-B radiation. Therefore, these findings present a novel knowledge for understanding the adaption of Antarctic moss to polar environments and provide a foundation for assessing the impact of global climate change on Antarctic land plants.

External Morphology of Larvae of Belgica antarctica Jacobs, 1900 (Diptera, Chironomidae) Obtained from Two Locations in Maritime Antarctica

The external morphology of the fourth-instar larva of the Antarctic endemic chironomid midge Belgica antarctica is described. Larvae were collected from Jougla Point (Wiencke Island) and an un-named island close to Enterprise Island, off the coast of the western Antarctic Peninsula. Light microscopy was used to examine and document photographically the structures of the mouthparts (mandible, mentum, premandible, labrum), antennae, pecten epipharyngis, clypeus, frontal apotome and posterior parapods. Measurements of the mouthparts are presented. The data obtained are compared with that available in the literature. A number of differences were identified relating to the size of the larvae, the number of teeth on the mandibles, the number of antennal segments and the length of the antennal blade. Malformations of the mandible and mentum are reported for the first time in this species. Features of larvae of taxonomic value that can be used to determine the species in larval stages are presented. These are of utility in using the larvae to reveal relationships with other species. Larvae are also important in ecological and genotoxicological studies, which require accurate species level identification.

International Response under the Antarctic Treaty System to the Establishment of A Non-native Fly in Antarctica

Antarctica currently has few non-native species, compared to other regions of the planet, due to the continent's isolation, extreme climatic conditions and the lack of habitat. However, human activity, particularly the activities of national government operators and tourism, increasingly contributes to the risk of non-native species transfer and establishment. Trichocera (Saltitrichocera) maculipennis Meigen, 1888 (Diptera, Trichoceridae) is a non-native fly originating from the Northern Hemisphere that was unintentionally introduced to King George Island in the maritime Antarctic South Shetland Islands around 15 years ago, since when it has been reported within or in the vicinity of several research stations. It is not explicitly confirmed that T. maculipennis has established in the natural environment, but life-history characteristics make this likely, thereby making potential eradication or control a challenge. Antarctic Treaty Parties active in the region are developing a coordinated and expanding international response to monitor and control T. maculipennis within and around stations in the affected area. However, there remains no overarching non-native invasive species management plan for the island or the wider maritime Antarctic region (which shares similar environmental conditions and habitats to those of King George Island). Here we present some options towards the development of such a plan. We recommend the development of (1) clear mechanisms for the timely coordination of response activities by multiple Parties operating in the vicinity of the introduction location and (2) policy guidance on acceptable levels of environmental impacts resulting from eradication attempts in the natural environment, including the use of pesticides.

Records of Parochlus steinenii in the Maritime Antarctic and sub-Antarctic regions

This study provides the summary of the reports of the geographical distribution in the Maritime Antarctic and sub-Antarctic regions of Parochlus steinenii (Gercke, 1889) (Diptera, Chironomidae), the only flying insect occurring naturally in the Antarctic continent. The distribution encompasses the South Shetland Islands (Maritime Antarctic), South Georgia (sub-Antarctic), and parts of the Cape Horn Biosphere Reserve (CHBR, southern Chile). In total 78 occurrence records were identified, 53 from our own records, 19 from the literature, and six from other data present in GBIF. Of the 78 records, 66 are from the South Shetland Islands, eight are from South Georgia, and four from the CHBR. This database was developed as one of the main objectives of two Chilean-funded research projects addressing understanding the effects of climate change on sub-Antarctic and Antarctic insects. It provides dataset documenting the distribution of Parochlus steinenii in the Maritime Antarctic, the sub-Antarctic, and the CHBR in southern South America (Chile). The complete dataset is available in Darwin Core Archive format via the Global Biodiversity Information Facility (GBIF).

Wind plays a major but not exclusive role in the prevalence of insect flight loss on remote islands

Terrestrial species on islands often show reduced dispersal abilities. For insects, the generality of explanations for island flight loss remains contentious. Although habitat stability is considered the most plausible explanation, others are frequently highlighted. Adopting a strong inference approach, we examined the hypotheses proposed to account for the prevalence of flightlessness in island insect assemblages, for a region long suspected to be globally unusual in this regard-the Southern Ocean Islands (SOIs). Combining comprehensive faunal inventories, species' morphological information, and environmental variables from 28 SOIs, we provide the first quantitative evidence that flightlessness is exceptionally prevalent among indigenous SOI insect species (47%). Prevalence among species which have evolved elsewhere is much lower: Arctic island species (8%), species introduced to the SOIs (17%), and globally (estimated as approx. 5%). Variation in numbers of flightless species and genera across islands is best explained by variation in wind speed, although habitat stability (thermal seasonality proxy) may play a role. Variables associated with insularity, such as island size, are generally poor predictors of flightlessness. The outcomes redirect attention to Darwin's wind hypothesis. They suggest, however, that wind selects for flightlessness through an energy trade-off between flight and reproduction, instead of by displacement from suitable habitats.

Environmental factors influencing fine-scale distribution of Antarctica's only endemic insect

Species distributions are dependent on interactions with abiotic and biotic factors in the environment. Abiotic factors like temperature, moisture, and soil nutrients, along with biotic interactions within and between species, can all have strong influences on spatial distributions of plants and animals. Terrestrial Antarctic habitats are relatively simple and thus good systems to study ecological factors that drive species distributions and abundance. However, these environments are also sensitive to perturbation, and thus understanding the ecological drivers of species distribution is critical for predicting responses to environmental change. The Antarctic midge, Belgica antarctica, is the only endemic insect on the continent and has a patchy distribution along the Antarctic Peninsula. While its life history and physiology are well studied, factors that underlie variation in population density within its range are unknown. Previous work on Antarctic microfauna indicates that distribution over broad scales is primarily regulated by soil moisture, nitrogen content, and the presence of suitable plant life, but whether these patterns are true over smaller spatial scales has not been investigated. Here we sampled midges across five islands on the Antarctic Peninsula and tested a series of hypotheses to determine the relative influences of abiotic and biotic factors on midge abundance. While historical literature suggests that Antarctic organisms are limited by the abiotic environment, our best-supported hypothesis indicated that abundance is predicted by a combination of abiotic and biotic conditions. Our results are consistent with a growing body of literature that biotic interactions are more important in Antarctic ecosystems than historically appreciated.

Molecular identification of Trichocera maculipennis, an invasive fly species in the Maritime Antarctic

Trichocera maculipennis, an invasive Diptera, was described for the first time in Antarctica in 2006 in a sewage system of one of the scientific stations on King George Island, South Shetland Islands, and started to increase its distribution within the island. To date, only taxonomical description of this species, based on morphological data has been available, as there were no molecular data recorded. In the present study, we present two methods of molecular identification of this species-based on partial cytochrome c oxidase subunit I (COI) and 16S ribosomal RNA (16S) genes. An appropriate and easy-to-use assay for proper and fast identification of invasive species is a key requirement for further management decisions, especially in such a fragile environment as found in terrestrial Antarctica.

Distribution and Habitat Preferences of the Newly Rediscovered Telmatogeton magellanicus (Jacobs, 1900) (Diptera: Chironomidae) on Navarino Island, Chile

The habitat of the intertidal flightless midge Telmatogeton magellanicus (Jacobs, 1900) is described for the first time from the northern coast of Navarino Island, Tierra del Fuego, Chile. Additionally, we report the first observations of adult behaviour in the wild. We delineate the species' distribution across three tidal zones (high, mid and low), and identify substrate characteristics that favour the presence of the midge. The mid-tide zone was the key habitat utilized by T. magellanicus, with lower densities in the low-tide zone and no presence in the high-tide zone. There was a strong association between the presence of larvae and filamentous algae, especially Bostrychia spp. and, to a lesser extent, Ulva spp., as well as between larvae and the presence of larger, more stable boulders. As a result, the species' overall distribution was widespread but patchy. We suggest that the main limiting factor is the relative humidity experienced in different habitats. One of the most striking features of the behavioural observations during data collection was the extremely active adults, which suggests high energy expenditure over a very short period of time. This may be due to the limited time available to find mates in a single low-tide period, when adults have about three hours after emerging from the pupa to complete mating and oviposition before inundation by the tide. The data presented here provide a baseline for future studies on this species' ecology, phenology, physiology and general biology.

Molecular identification of Trichocera maculipennis, an invasive fly species in the Maritime Antarctic

Trichocera maculipennis, an invasive Diptera, was described for the first time in Antarctica in 2006 in a sewage system of one of the scientific stations on King George Island, South Shetland Islands, and started to increase its distribution within the island. To date, only taxonomical description of this species, based on morphological data has been available, as there were no molecular data recorded. In the present study, we present two methods of molecular identification of this species-based on partial cytochrome c oxidase subunit I (COI) and 16S ribosomal RNA (16S) genes. An appropriate and easy-to-use assay for proper and fast identification of invasive species is a key requirement for further management decisions, especially in such a fragile environment as found in terrestrial Antarctica.

Assessing distribution shifts and ecophysiological characteristics of the only Antarctic winged midge under climate change scenarios

Parts of Antarctica were amongst the most rapidly changing regions of the planet during the second half of the Twentieth Century. Even so, today, most of Antarctica remains in the grip of continental ice sheets, with only about 0.2% of its overall area being ice-free. The continent's terrestrial fauna consists only of invertebrates, with just two native species of insects, the chironomid midges Parochlus steinenii and Belgica antarctica. We integrate ecophysiological information with the development of new high-resolution climatic layers for Antarctica, to better understand how the distribution of P. steinenii may respond to change over the next century under different IPCC climate change scenarios. We conclude that the species has the potential to expand its distribution to include parts of the west and east coasts of the Antarctic Peninsula and even coastal ice-free areas in parts of continental Antarctica. We propose P. steinenii as an effective native sentinel and indicator species of climate change in the Antarctic.

Invasive non-native species likely to threaten biodiversity and ecosystems in the Antarctic Peninsula region

The Antarctic is considered to be a pristine environment relative to other regions of the Earth, but it is increasingly vulnerable to invasions by marine, freshwater and terrestrial non-native species. The Antarctic Peninsula region (APR), which encompasses the Antarctic Peninsula, South Shetland Islands and South Orkney Islands, is by far the most invaded part of the Antarctica continent. The risk of introduction of invasive non-native species to the APR is likely to increase with predicted increases in the intensity, diversity and distribution of human activities. Parties that are signatories to the Antarctic Treaty have called for regional assessments of non-native species risk. In response, taxonomic and Antarctic experts undertook a horizon scanning exercise using expert opinion and consensus approaches to identify the species that are likely to present the highest risk to biodiversity and ecosystems within the APR over the next 10 years. One hundred and three species, currently absent in the APR, were identified as relevant for review, with 13 species identified as presenting a high risk of invading the APR. Marine invertebrates dominated the list of highest risk species, with flowering plants and terrestrial invertebrates also represented; however, vertebrate species were thought unlikely to establish in the APR within the 10 year timeframe. We recommend (a) the further development and application of biosecurity measures by all stakeholders active in the APR, including surveillance for species such as those identified during this horizon scanning exercise, and (b) use of this methodology across the other regions of Antarctica. Without the application of appropriate biosecurity measures, rates of introductions and invasions within the APR are likely to increase, resulting in negative consequences for the biodiversity of the whole continent, as introduced species establish and spread further due to climate change and increasing human activity.

Exposure of an urban population to pesticides assessed by wastewater-based epidemiology in a Caribbean island

Wastewater-based epidemiology is an innovative approach to estimate the consumption of chemicals and their exposure patterns in a population, on the basis of measurements of biomarkers in wastewater. This method can provide objective real-time information on xenobiotics directly or indirectly ingested by a population. This approach was used to examine the exposure of the Martinique population to the three classes of pesticides: triazines, organophosphates and pyrethroids. Martinique island (French West Indies) is a closed market and has been closely monitored since the early 2000's when contamination with chlordecone, an organochlorine insecticide widely applied between 1972 and 1993 in banana plantations, became a critical political issue. The aim of this study was to identify and quantify the patterns of human exposure and compare the results to those from other countries. Wastewater was collected as 24-h composite samples and analysed for selected urinary pesticide metabolites by liquid chromatography-tandem mass spectrometry. Organophosphate and pyrethroid metabolites were found in all the samples up to 330 ng/L, while triazines were found only at trace levels. Mass loads indicated higher exposure to pyrethroids than in some cities in Europe, but lower exposure to triazines and organophosphates. The estimated human intake for pyrethroids was close to the Acceptable Daily Intake, but importation of these pesticides to Martinique was low. This study illustrates the high human exposure with indoor pesticide use in comparison to its use in agriculture.

Not so free range? Oviposition microhabitat and egg clustering affects Eretmoptera murphyi (Diptera: Chironomidae) reproductive success

Understanding the physiology of non-native species in Antarctica is key to elucidating their ability to colonise an area, and how they may respond to changes in climate. Eretmoptera murphyi is a chironomid midge introduced to Signy Island (Maritime Antarctic) from South Georgia (Sub-Antarctic) where it is endemic. Here, we explore the tolerance of this species' egg masses to heat and desiccation stress encountered within two different oviposition microhabitats (ground surface vegetation and underlying soil layer). Our data show that, whilst oviposition takes place in both substrates, egg sacs laid individually in soil are at the greatest risk of failing to hatch, whilst those aggregated in the surface vegetation have the lowest risk. The two microhabitats are characterised by significantly different environmental conditions, with greater temperature fluctuations in the surface vegetation, but lower humidity (%RH) and available water content in the soil. Egg sacs were not desiccation resistant and lost water rapidly, with prolonged exposure to 75% RH affecting survival for eggs in singly oviposited egg sacs. In contrast, aggregated egg sacs (n = 10) experienced much lower desiccation rates and survival of eggs remained above 50% in all treatments. Eggs had high heat tolerance in the context of the current microhabitat conditions on Signy. We suggest that the atypical (for this family) use of egg sac aggregation in E. murphyi has developed as a response to environmental stress. Current temperature patterns and extremes on Signy Island are unlikely to affect egg survival, but changes in the frequency and duration of extreme events could be a greater challenge.

Life cycle and phenology of an Antarctic invader: the flightless chironomid midge, Eretmoptera murphyi

Knowledge of the life cycles of non-native species in Antarctica is key to understanding their ability to establish and spread to new regions. Through laboratory studies and field observations on Signy Island (South Orkney Islands, maritime Antarctic), we detail the life stages and phenology of Eretmoptera murphyi (Schaeffer 1914), a brachypterous chironomid midge introduced to Signy in the 1960s from sub-Antarctic South Georgia where it is endemic. We confirm that the species is parthenogenetic and suggest that this enables E. murphyi to have an adult emergence period that extends across the entire maritime Antarctic summer season, unlike its sexually reproducing sister species Belgica antarctica which is itself endemic to the Antarctic Peninsula and South Shetland Islands. We report details of previously undescribed life stages, including verification of four larval instars, pupal development, egg gestation and development, reproductive viability and discuss potential environmental cues for transitioning between these developmental stages. Whilst reproductive success is limited to an extent by high mortality at eclosion, failure to oviposit and low egg-hatching rate, the population is still able to potentially double in size with every life cycle.

The influence of vegetation and soil properties on springtail communities in a diesel-contaminated soil

Soil health is important for the functioning of all terrestrial ecosystems, but may be impacted by contamination. Soil contamination may in turn necessitate rehabilitation and remediation works, but many of the techniques currently used cause physical disturbance to the soil structure, which may in itself affect soil assemblages. An understanding of the relative influence of these two types of disturbance on soil biota is needed to inform in situ remediation activities. Subantarctic Macquarie Island provides an ideal location to study these interactions because soil biodiversity is naturally low and a number of diesel spills have undergone active in situ remediation in recent years. In this study, soil cores were collected in triplicate from 21 locations. Springtails were extracted and identified to genus/species level. Total petroleum hydrocarbon (TPH) concentrations were measured at the surface and at 0.5m depth at each site, as was vegetation coverage and a range of soil properties. The relationships between these data were examined using distance-based linear models. Together, all environmental variables (vegetation and soil properties) explained a total of 76% of the variation in springtail assemblages. Soil properties alone accounted for 52% of the variation in springtail assemblages, of which bulk density was most important followed by soil conductivity and pH. Vegetation cover by the four plant taxa accounted for 34% of variation observed, with Leptinella plumosa and Poa foliosa having the greatest influence. Surface and underlying TPH concentration did not have a significant effect on springtail assemblages. Overall, factors that can be linked to physical soil disturbance had greater influence over springtail assemblages than did soil contamination. This finding may influence the selection of the most appropriate contaminant management approach for environmentally sensitive sites.