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Eglinton, United Kingdom

Bilton D.T.,University of Plymouth | Foster G.N.,Aquatic Coleoptera Conservation Trust
PeerJ | Year: 2016

Sexual conflict drives both inter- and intrasexual dimorphisms in many diving beetles, where male persistence and female resistance traits co-evolve in an antagonistic manner. To date most studies have focussed on species where rough and smooth females and their associated males typically co-occur within populations, where phenotype matching between morphs may maintain forms as stable polymorphisms. The Palaearctic diving beetle Hydroporus memnonius is characterised by having dimorphic (rough var. castaneus and smooth, shining) females and associated males which differ in persistence traits; the two forms being largely distributed parapatrically. In this species, instead of mating trade-offs between morphs, males associated with castaneus females should have a mating advantage with both this form and shining females, due to their increased persistence abilities on either cuticular surface. This may be expected to lead to the replacement of the shining form with castaneus in areas where the two come into contact. Using data collected over a thirty year period, we show that this process of population replacement is indeed occurring, castaneus having expanded significantly at the expense of the shining female form. Whilst populations of both forms close to the contact zone appear to differ in their thermal physiology, these differences are minor and suggest that the expansion of castaneus is not linked to climatic warming in recent decades. Instead we argue that the observed spread of castaneus and its associated male may result from the dynamics of sexually antagonistic coevolution in this beetle. © 2016 Bilton and Foster.

Drinan T.J.,University College Cork | Foster G.N.,Aquatic Coleoptera Conservation Trust | Nelson B.H.,National Parks and Wildlife Service | O'Halloran J.,University College Cork | Harrison S.S.C.,University College Cork
Biological Conservation | Year: 2013

Small blanket bog lakes can contain many rare and threatened aquatic invertebrate species. Their conservation value, however, is threatened throughout Europe by peat extraction and particularly conifer afforestation, which can compromise the physico-chemical habitat quality of peatland lakes through excessive inputs of forestry-derived dissolved and particulate substances. To quantify the effect of conifer plantation forestry on the conservation value of these habitats, we compared the hydrochemistry and assemblages of aquatic Coleoptera, Heteroptera and Odonata of replicate lakes across three distinct catchment land uses: (i) unplanted blanket bog only present in the catchment, (ii) mature conifer plantation forests only present in the catchment and (iii) catchments containing mature conifer plantation forests with recently clearfelled areas. All three catchment land uses were replicated across regions of sedimentary and igneous geology. Lakes with afforested catchments, in both geologies, had elevated concentrations of plant nutrients, total dissolved organic carbon and heavy metals, the highest concentrations being recorded from the clearfell lakes. Coleoptera and Heteroptera assemblages responded strongly to forestry-mediated changes in water chemistry, whereas Odonata assemblages responded more to catchment geology - geology being confounded by altitudinal differences between lakes. The greatest species-quality scores (SQSs) and species richness were recorded from the clearfell lakes. Three of the four International Union for the Conservation of Nature (IUCN) nationally red-listed species recorded during this study were, however, absent from clearfell lakes. Our findings demonstrate that plantation forestry can have a profound impact on the aquatic macroinvertebrate assemblages and conservation value of small blanket bog lakes, primarily via eutrophication. Despite indices such as SQS scores and species richness appearing to reveal a beneficial response of blanket bog lake communities to habitat deterioration, they mask that certain 'emblematic' species are being severely negatively impacted by the disturbance caused by plantation forestry. Considering the need for fertiliser to produce economically viable plantation forest crops, coupled with the inefficiencies of peat soils in retaining applied nutrients, the degradation of peatland lakes is likely to become more prevalent as plantation forestry continues to expand worldwide. © 2012 Elsevier Ltd.

Foster G.N.,Aquatic Coleoptera Conservation Trust | Close R.E.,1 Craigbrae Cottages
Archives of Natural History | Year: 2014

David Sharp (1840-1922) was one of Britain's most eminent entomologists. He was qualified as a medical doctor and, from 1867 to 1883, his sole patient was a member of the Scottish nobility who had been declared insane. This was one of Sharp's most productive periods as an entomologist during which he would have amassed a significant amount of money, allowing him to continue to practise entomology well into the twentieth century. © The Society for the History of Natural History.

Bray R.A.,Natural History Museum in London | Foster G.N.,Aquatic Coleoptera Conservation Trust | Waeschenbach A.,Natural History Museum in London | Littlewood D.T.J.,Natural History Museum in London
Zootaxa | Year: 2012

Progenetic specimens of Allocreadium neotenicum Peters, 1957 are described from water beetles, Hydroporus rufifrons, an endangered species, and Agabus paludosus from northern England and Scotland, and as non-ovigerous metacercariae from Agabus melanarius from southern England. Morphologically, the worms are identical to A. neotenicum described from water beetles in North America. Molecular phylogenetic estimates based on 28S rDNA sequences show these British specimens as more closely related to the North American freshwater fish parasite Allocreadium lobatum Wallin, 1909 than to the European species A. isoporum (Looss, 1894). A. lobatum shows a predilection for progenesis and may be a senior synonym of A. neotenicum. Based on the molecular phylogeny, the genus Pseudallocreadium Yamaguti, 1971 is considered synonymous with Allocreadium and the two species assigned to that genus, P. neotenicum and P. alloneotenicum (Wootton, 1957) are returned to Allocreadium. Copyright © 2012, Magnolia Press.

Bergsten J.,Swedish Museum of Natural History | Bergsten J.,Natural History Museum in London | Bergsten J.,Imperial College London | Bilton D.T.,University of Plymouth | And 15 more authors.
Systematic Biology | Year: 2012

Eight years after DNA barcoding was formally proposed on a large scale, CO1 sequences are rapidly accumulating from around the world. While studies to date have mostly targeted local or regional species assemblages, the recent launch of the global iBOL project (International Barcode of Life), highlights the need to understand the effects of geographical scale on Barcoding's goals. Sampling has been central in the debate on DNA Barcoding, but the effect of the geographical scale of sampling has not yet been thoroughly and explicitly tested with empirical data. Here, we present a CO1 data set of aquatic predaceous diving beetles of the tribe Agabini, sampled throughout Europe, and use it to investigate how the geographic scale of sampling affects 1) the estimated intraspecific variation of species, 2) the genetic distance to the most closely related heterospecific, 3) the ratio of intraspecific and interspecific variation, 4) the frequency of taxonomically recognized species found to be monophyletic, and 5) query identification performance based on 6 different species assignment methods. Intraspecific variation was significantly correlated with the geographical scale of sampling (R-square = 0.7), and more than half of the species with 10 or more sampled individuals (N = 29) showed higher intraspecific variation than 1% sequence divergence. In contrast, the distance to the closest heterospecific showed a significant decrease with increasing geographical scale of sampling. The average genetic distance dropped from > 7% for samples within 1 km, to < 3.5% for samples up to > 6000 km apart. Over a third of the species were not monophyletic, and the proportion increased through locally, nationally, regionally, and continentally restricted subsets of the data. The success of identifying queries decreased with increasing spatial scale of sampling; liberal methods declined from 100% to around 90%, whereas strict methods dropped to below 50% at continental scales. The proportion of query identifications considered uncertain (more than one species < 1% distance from query) escalated from zero at local, to 50% at continental scale. Finally, by resampling the most widely sampled species we show that even if samples are collected to maximize the geographical coverage, up to 70 individuals are required to sample 95% of intraspecific variation. The results show that the geographical scale of sampling has a critical impact on the global application of DNA barcoding. Scale-effects result from the relative importance of different processes determining the composition of regional species assemblages (dispersal and ecological assembly) and global clades (demography, speciation, and extinction). The incorporation of geographical information, where available, will be required to obtain identification rates at global scales equivalent to those in regional barcoding studies. Our result hence provides an impetus for both smarter barcoding tools and sprouting national barcoding initiatives - smaller geographical scales deliver higher accuracy. © The Author(s) 2012. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved.

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