World‐wide decreases of insect abundance and diversity are of major concern because of their importance for ecosystem functioning and the stability of ecosystems. Various studies reported dramatic declines of butterflies, wild bees and beetles in agricultural areas. Yet, evidence for decreasing abundance in cryptic insect species is scarce.
Using a transect‐count technique, we monitored the relative population size of the endangered flightless grassland longhorn beetle Iberodorcardion fuliginator in 13 dry, semi‐natural grassland sites in the border region of Switzerland, France, and Germany at yearly intervals over 20 years (1999–2018). To disentangle potential causes for changes in I. fuliginator abundance over time, we recorded quantitatively the plant communities in all sites in 2004 and 2017 and changes in other habitat characteristics.
We found that the overall abundance of I. fuliginator individuals decreased by 90% over 20 years: at one site the population went extinct, at five sites the populations were critically decreasing, at four sites the populations were decreasing and at only three sites population size remained stable.
Linear models revealed that the factor ‘change in plant species composition’ is the main driver for the decrease in beetle abundance. Alternative models indicated that – in addition to vegetation changes – area of suitable habitat and low heat load affected the probability of decreasing population size.
Our study shows that gradual habitat deterioration measured as reduction in grass cover and change in plant species composition negatively affect the abundance of the highly specialised beetle I. fuliginator.
A revision of the Blattodea, Ensifera and Caelifera described by H. Fruhstorfer. -Twelve taxa described by Fruhstorfer are revised, belonging to Blattodea: Blattellidae (1), Ensifera: Phaneropteridae (1), Tettigoniidae (4) and Caelifera: Acrididae (6). Name-bearing types are deposited in the Swiss Federal Institute of Technology, Zurich (7), the Zoologische Staatssammlung, Munich (1) and the Natural History Museums of Berlin (1) and Geneva (4). Syntype series of two taxa are missing. In seven cases lectotypes are here designated. Four new synonymies are established: Tettigoniidae: Ephippiger ephippiger eustra-
The sampling of living insects should be avoided in highly endangered species when the sampling would further increase the risk of population extinction. Nonlethal sampling (wing clips or leg removals) can be an alternative to obtain DNA of individuals for population genetic studies. However, nonlethal sampling may not be possible for all insect species. We examined whether remnants of traffic-killed specimens of the endangered and protected flighless longhorn beetle Iberodorcadion fuliginator (L., 1758) can be used as a resource for population genetic analyses. Using insect fragments of traffic-killed specimens collected over 15 yr, we determined the most efficient DNA extraction method in relation to the state of the specimens (crushed, fragment, or intact), preservation (dried, airtight, or in ethanol), storage duration, and weight of the sample by assessing the quantity and quality of genomic DNA. A modified cetyltrimethyl ammonium bromide method provided the highest recovery rate of genomic DNA and the largest yield and highest quality of DNA. We further used traffic-killed specimens to evaluate two DNA amplification techniques (quantitative polymerase chain reaction [qPCR] and microsatellites). Both qPCR and microsatellites revealed successful DNA amplification in all degraded specimens or beetle fragments examined. However, relative qPCR concentration and peak height of microsatellites were affected by the state of specimen and storage duration but not by specimen weight. Our investigation demonstrates that degraded remnants of traffic-killed beetle specimens can serve as a source of high-quality genomic DNA, which allows to address conservation genetic issues.
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