We examined the phylogenetic relationships between species and genera within the caddisfly subfamily Drusinae (Trichoptera: Limnephilidae) using sequence data from two mitochondrial loci (cytochrome oxidase 1, large subunit rRNA) and one nuclear gene (wingless). Sequence data were analysed for 28 species from five genera from the subfamily. We analysed individual and combined data sets using a Bayesian Markov Chain Monte Carlo and a maximum parsimony approach and compared the performance of each partition for resolving phylogenetic relationships at this level. In terms of resolution and phylogenetic utility wingless outperformed the two mitochondrial gene partitions. Using both Shimodaira-Hasegawa and expected likelihood weights tests we tested several hypotheses of relationships previously inferred based on adult morphological characters. The data did not support the generic concept, or many previously proposed species groupings, based on adult morphology. In contrast, the molecular data correlated with the morphology and feeding ecology of larvae. Using Bayesian ancestral character state reconstructions we inferred the evolution of feeding ecology and relevant larval morphological characters. Our analyses showed that within the subfamily Drusinae two derived feeding types evolved. One of these--grazing epilithic algae--is otherwise unusual in the Limnephilidae and may have promoted the high degree of diversity in the Drusinae.
The paper provides a synoptic key to the genera of final instar European Trichoptera larvae. The most important characters are illustrated by colour photos, with arrows highlighting the diagnostic features. A short descriptive text gives additional information for each decision and guides the reader through the determination process.
The caddisfly subfamily Drusinae BANKS comprises roughly 100 species inhabiting mountain ranges in Europe, Asia Minor and the Caucasus. A 3-gene phylogeny of the subfamily previously identified three major clades that were corroborated by larval morphology and feeding ecologies: scraping grazers, omnivorous shredders and filtering carnivores. Larvae of filtering carnivores exhibit unique head capsule complexities, unknown from other caddisfly larvae. Here we assess the species-level relationships within filtering carnivores, hypothesizing that head capsule complexity is derived from simple shapes observed in the other feeding groups. We summarize the current systematics and taxonomy of the group, clarify the systematic position of Cryptothrix nebulicola, and present a larval key to filtering carnivorous Drusinae. We infer relationships of all known filtering carnivorous Drusinae and 34 additional Drusinae species using Bayesian species tree analysis and concatenated Bayesian phylogenetic analysis of 3805bp of sequence data from six gene regions (mtCOI5-P, mtCOI3-P, 16S mrDNA, CADH, WG, 28S nrDNA), morphological cladistics from 308 characters, and a total evidence analysis. All analyses support monophyly of the three feeding ecology groups but fail to fully resolve internal relationships. Within filtering carnivores, variation in head setation and frontoclypeus structure may be associated with progressive niche adaptation, with less complex species recovered at a basal position. We propose that diversification of complex setation and frontoclypeus shape represents a recent evolutionary development, hypothetically enforcing speciation and niche specificity within filtering carnivorous Drusinae.
BackgroundTaxonomy offers precise species identification and delimitation and thus provides basic information for biological research, e.g. through assessment of species richness. The importance of molecular taxonomy, i.e., the identification and delimitation of taxa based on molecular markers, has increased in the past decade. Recently developed exploratory tools now allow estimating species-level diversity in multi-locus molecular datasets.ResultsHere we use molecular species delimitation tools that either quantify differences in intra- and interspecific variability of loci, or divergence times within and between species, or perform coalescent species tree inference to estimate species-level entities in molecular genetic datasets. We benchmark results from these methods against 14 morphologically readily differentiable species of a well-defined subgroup of the diverse Drusinae subfamily (Trichoptera, Limnephilidae). Using a 3798 bp (6 loci) molecular data set we aim to corroborate a geographically isolated new species by integrating comparative morphological studies and molecular taxonomy.ConclusionsOur results indicate that only multi-locus species delimitation provides taxonomically relevant information. The data further corroborate the new species Drusus zivici sp. nov. We provide differential diagnostic characters and describe the male, female and larva of this new species and discuss diversity patterns of Drusinae in the Balkans. We further discuss potential and significance of molecular species delimitation. Finally we argue that enhancing collaborative integrative taxonomy will accelerate assessment of global diversity and completion of reference libraries for applied fields, e.g., conservation and biomonitoring.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-017-0972-5) contains supplementary material, which is available to authorized users.
BackgroundVector-pathogen dynamics are controlled by fluctuations of potential vector communities, such as the Culicidae. Assessment of mosquito community diversity and, in particular, identification of environmental parameters shaping these communities is therefore of key importance for the design of adequate surveillance approaches. In this study, we assess effects of climatic parameters and habitat structure on mosquito communities in eastern Austria to deliver these highly relevant baseline data.MethodsFemale mosquitoes were sampled twice a month from April to October 2014 and 2015 at 35 permanent and 23 non-permanent trapping sites using carbon dioxide-baited traps. Differences in spatial and seasonal abundance patterns of Culicidae taxa were identified using likelihood ratio tests; possible effects of environmental parameters on seasonal and spatial mosquito distribution were analysed using multivariate statistical methods. We assessed community responses to environmental parameters based on 14-day-average values that affect ontogenesis.ResultsAltogether 29,734 female mosquitoes were collected, and 21 of 42 native as well as two of four non-native mosquito species were reconfirmed in eastern Austria. Statistical analyses revealed significant differences in mosquito abundance between sampling years and provinces. Incidence and abundance patterns were found to be linked to 14-day mean sunshine duration, humidity, water–level maxima and the amount of precipitation. However, land cover classes were found to be the most important factor, effectively assigning both indigenous and non-native mosquito species to various communities, which responded differentially to environmental variables.ConclusionsThese findings thus underline the significance of non-climatic variables for future mosquito prediction models and the necessity to consider these in mosquito surveillance programmes.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-017-2140-6) contains supplementary material, which is available to authorized users.
Two new species of the genus Drusus (Trichoptera, Limnephilidae, Drusinae) from the Western Balkans are described. Additionally, observations on the biodiversity and threats to the region’s endemic aquatic fauna are discussed. Drusus krpachi sp. n. is a micro-endemic of the Korab Mountains, Macedonia, and Drusus malickyi sp. n. is a micro-endemic of the Prokletije Mountains, Albania. Both new species are most similar to Drusus macedonicus but differ from the latter in the shape of segment IX, the shape of the tips of the intermediate appendages in lateral view, the shape of the inferior appendages, and the form and shape of the parameres. In addition, males of the European species of filtering carnivore Drusinae are diagnosed and illustrated, including Cryptothrix nebulicola McLachlan, Drusus chrysotus Rambur, Drusus discolor Rambur, Drusus macedonicus Schmid, Drusus meridionalis Kumanski, Drusus muelleri McLachlan, Drusus romanicus Murgoci and Botosaneanu, and Drusus siveci Malicky. These additions to the Western Balkan fauna demonstrate the significance of this region for European biodiversity and further highlight the importance of faunistic studies in Europe.
Species of the genus Drusus usually inhabit cold springs and spring areas of mountain streams. Isolation of populations and a patchy distribution are reasons for high diversity and endemism in this genus. Nine taxa from the bosnicus group (genus Drusus) live in the Balkan Peninsula (Croatia, Bosnia and Herzegovina, Montenegro, Macedonia). This study has two main objectives. First, morphological, ecological, and genetic features (mitochondrial COI and 16S genes) of the final larval instar of Drusus radovanovici radovanovici from Bosnia and Herzegovina are analysed. Association of larvae and adults of D. radovanovici radovanovici is carried out according to genetic data (mitochondrial DNA) of adults and larvae, and supported by their distribution in Bosnia and Herzegovina. Second, phylogeny, taxonomy and distribution of taxa of the bosnicus group in the Balkan Peninsula are discussed. The analysis includes morphological and genetic data for the known larvae of the genus Drusus distributed in the Balkans. As a consequence, both subspecies of Drusus radovanovici are ranked as species (D. radovanovici and D. septentrionis stat. n.), and the status of other taxa from the bosnicus group is discussed. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Due to the erosiveness of their sediments, sandstone streams transport high loads of fine particles. The catchment of the Weidlingbach, a 12 km long tributary of the Danube northwest of Vienna, is dominated by calcareous sandstone, marl and slate. Mean sediment grain size ranges from 29.3 to 31.0 mm, and mean pore volume is approximately 20%. The third order study site is divided into a wide, shallow riffle section with high accumulations of fine sediments in the hyporheic zone and a narrow, deep run section with a lower percentage of fine sediments. Invertebrates were sampled to a sediment depth of 60 cm every second month using the freeze-coring-technique with electropositioning.Hyporheic invertebrate densities were significantly higher in sediments of the run than in those of the riffle section. Generally, hyporheic abundances decreased with increasing depth; however, the decline was more distinct within the riffle than the run section. Furthermore, we observed a strong negative correlation between the percentage of fine sediments (<2 mm) and hyporheic invertebrate densities.
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