The author described properties of 26 types of vibration-sensitive interneurons identified in a primitive ensiferan insect. As based for the first time on a large number of individually identified neurons, predominant sensitivity of the central neural network to low-frequency vibration was demonstrated for Ensifera. Anatomy and response properties were described in detail for those neural elements with no putative homologues known in other insect species. The work emphasises the importance of perception of low-frequency vibration signals for the Orthoptera and insects in general, and also represents a basis for extensive interspecific comparisons of neurons in the future.
COBISS.SI-ID: 2053967
We investigated the interaction of intergenerational temperature and food quality change on the fitness of two species of Daphnia. The effect of a change in temperature (15°C vs. 20°C) and food quality (Cryptomonas sp. as high-quality food vs. Chlamydomonas sp. as relatively low-quality food) on juvenile growth rate and clutch size of Daphnia magna and Daphnia pulex was measured in 16 different combinations of maternal and offspring environments in standardized growth assays. It was shown that studies conducted under constant temperature conditions may seriously underestimate dietary constraints in natural environments.
COBISS.SI-ID: 29448409
Pentatomid bugs communicate using substrate-borne vibrational signals that are transmitted along herbaceous plant stems in the form of bending waves. We tested the prediction that amplitude variation with distance from the emitter is caused by resonance, by measuring amplitude profiles of different vibrational signals transmitted along the stem of a Cyperus alternifolius plant, and comparing their frequencies and patterns with calculated spatial profiles of corresponding eigenfrequencies of a model system. Both parameters of the physical model matched the measured values, confirming the hypothesis and opening further questions about the insect vibrational communication system.
COBISS.SI-ID: 2502735
A combination of fieldwork and laboratory experiments was used to test the hypothesis that predators can intercept and exploit sexual communication signals of their prey. First, we developed and characterized PCR primers specific for leafhoppers of the genus Aphrodes and specifically for the species A. makarovi. Spiders were collected from sites where leafhoppers were present and screened with these primers to establish which spider species were significant predators of this species during the mating period of these leafhoppers. Analysis using PCR of the gut contents of tangle-web spiders, Enoplognatha ovata (Theridiidae), showed that they consume leafhoppers in the field at a greater rate when signalling adults were present than when nymphs were dominant, suggesting that the spiders were using these vibrations signals to find their prey. Playback and microcosm experiments then showed that E. ovata can use the vibrational signals of male leafhoppers as a cue during foraging and, as a result, killed significantly more male than female A. makarovi.
COBISS.SI-ID: 2349903
In the article are presented the results from 235 high-mountain lakes across Europe collected during EMERGE project, where communities of different groups of organisms were analysed. The lakes are grouped in hierarchical principle. The most important parameters, determining community structure are: lake size, trophic level, alkalinity and ice-cove duration. For each group of organisms treshold values, where community structure is significantly changed, were determined (lake size: 3 ha; trophic level: 0.6 mg C l-1; ice-cover: 190 days, alcalinity: 200 µeq l-1).
COBISS.SI-ID: 2124367