Search results for "beetles"
showing 5 items of 35 documents
Subtropical streams harbour higher genus richness and lower abundance of insects compared to boreal streams, but scale matters
2018
Aim: Biological diversity typically varies between climatically different regions, and regions closer to the equator often support higher numbers of taxa than those closer to the poles. However, these trends have been assessed for a few organism groups, and the existing studies have rarely been based on extensive identical surveys in different climatic regions. Location: We conducted standardized surveys of wadeable streams in a boreal (western Finland) and a subtropical (south-eastern Brazil) region, sampling insects identically from 100 streams in each region and measuring the same environmental variables in both regions. Taxon: Aquatic insects. Methods: Comparisons were made at the scale…
Dead wood profile of a semi-natural boreal forest – implications for sampling
2019
Dead wood profile of a forest is a useful tool for describing forest characteristics and assessing forest disturbance history. Nevertheless, there are few studies on dead wood profiles, including both coarse and fine dead wood, and on the effect of sampling intensity on the dead wood estimates. In a semi-natural boreal forest, we measured every dead wood item over 2 cm in diameter from 80 study plots. From eight plots, we further recorded dead wood items below 2 cm in diameter. Based on these data we constructed the full dead wood profile, i.e. the overall number of dead wood items and their distribution among different tree species, volumes of different size and decay stage categories. We …
Chrząszcze w soli
2018
Kopalnia Soli „Wieliczka” jest obiektem sztucznie stworzonym przez człowieka, dawniej eksploatowanym, obecnie intensywnie odwiedzanym. Dzięki kopalni powstała nowa nisza ekologiczna, którą zaczęły zasiedlać troglofilne organizmy żywe. Jednymi z ciekawszych zwierząt żyjących w tej kopalni są chrząszcze Niptus hololeucus. Naturalnie występują w miejscach niezwiązanych z solnymi systemami podziemnymi, jednak zawleczone przystosowały się do troglobiontycznego trybu życia. Obecnie prowadzone badania ukierunkowane są m.in. na biologiczne i morfologiczne porównanie populacji troglofilnych z kopalni i żyjących poza nią. W tym celu przy pomocy pułapek Barbera pobierane są próby z 13 stanowisk z pozi…
Aposematism in the burying beetle? Dual function of anal fluid in parental care and chemical defence
2017
Burying beetles (Nicrophorus vespilloides) bear distinctive and variable orange-black patterning on their elytra and produce an anal exudate from their abdomen when threatened. During breeding, the anal exudates contribute to the antimicrobial defence of the breeding resource. We investigated whether the anal exudates also provide a responsive chemical defence, which is advertised to potential avian predators by the beetle’s orange and black elytral markings. We found that that the orange-black elytral markings of the burying beetle are highly conspicuous for avian predators against range of backgrounds, by using computer simulations. Using bioassays with wood ants, we also showed that the …
Habitat area and local habitat conditions outweigh fragmentation effects on insect communities in vineyards
2022
Fragmentation of habitat, for example by intensive agricultural practices, can be detrimental to local biodiversity. However, it often remains unclear whether such biodiversity declines are caused by loss of habitat area or increased fragmentation, and how habitat quality factors into it. In our study system, vegetated vineyards are typically small, and isolated from one another, potentially limiting the distribution and dispersal of organisms. In a full-factorial experiment of a priori selected vegetated vineyard patches of differing size and fragmentation, we aimed to disentangle the effects of habitat area (area of vegetated vineyards), habitat fragmentation (number of vegetated vineyard…