Continued population growth could lead to protein deficiency in the human diet. To counteract this risk, attempts are being made to identify new edible sources of protein. The aim of this paper was to review the existing literature and to analyse the current state of yellow mealworm (Tenebrio molitor) rearing for food and feed, especially in Europe. The yellow mealworm is the most widely bred and traded insect species in Europe that has high feed conversion ratio; 3.4 to 6.1 kg of feed ingested per kg of harvested larvae. Mealworms could compete with livestock due to their high protein and fat content and low environmental impact. Mealworms have been extensively researched as a source of feed for animals, including poultry, fish, pets and birds. Its nutrient content depends on the processing method, where thermal processing is least desirable. Mealworms are characterised by a high and variable microbial load which has to be reduced before consumption. The antibiotics, pesticides and other substances should also be analysed to ensure that mealworms are a safe protein source for human consumption. The nutritional benefits of mealworms have to be communicated to European consumers who are generally averse to eating insects.

Research on the ecology of water mites in flowing water has focused mainly on analysis of factors directly affecting these organisms in the aquatic environment. The hypothesis of this study was that apart from factors acting within the aquatic environment, the formation of Hydrachnidia communities in lotic ecosystems may also be affected by factors acting in the terrestrial environment. The analysis was made at three different levels of organization of the environment: (1) landscape level (sub-catchments, terrestrial environment), (2) macrohabitat level (sampling sites, aquatic environment) and (3) mesohabitat level (sampling sub-sites, aquatic environment). Some correlation was noted between certain species and some sub-catchment parameters. This may indicate a link between some landscape features (terrestrial environment) and the formation of water mite assemblages in the river. The low percentage for physicochemical parameters together in explaining the variance in occurrence of species, very low correlations between species and physicochemical parameters and the discrepancy in the grouping of sites in the case of faunal data and data on the physicochemical indicates that physicochemical factors had little influence on water mites. Taking into account all three levels of organization of the environment analyzed, we can say that at the landscape level we can find only indirect relationships between environmental factors and the fauna inhabiting the aquatic environment; at the macrohabitat level the description of Hydrachnidia is more precise but still of a general nature. Only analysis at the mesohabitat level fully explains the specific character of Hydrachnidia assemblages.

Knowledge and management of aquatic ecosystems (formerly Bulletin Français de la Pèche et de la Pisciculture), an international journal on freshwater ecosystem

Using the example of a regulated stretch of the Krąpiel River (NW Poland), an analysis of the impact of dredging on the aquatic beetle (Coleoptera) fauna was made. After dredging the beetle fauna became markedly poorer quantitatively and had lower species diversity. Moreover, the qualitative composition and dominance structure were highly transformed. However, species number and diversity increased rapidly and were restored within just half a year. The structure of the restored fauna was most strongly influenced by vegetation, flow velocity and bottom sediment composition. The first to colonize the river were eurytopic beetles and species typical of small water bodies, which had significant refuges in the form of fish ponds bordering on the river; these species dominated the assemblage throughout the study period. Rheophiles with less dispersal power appeared later, and finally rheobionts, in low numbers but occupying an increasing number of sampling sites.

The present study is a discussion of the interactions between different types of water bodies in the spatial arrangement of a river valley, taking into account landscape data. The Hydrachnidia assemblages in particular types of valley water bodies (oxbows, riparian pools, permanent ponds, flooded alder carrs, sedge marshes, and springs) are strongly influenced by the spatial arrangement of the water bodies in the landscape. Moreover, the formation of a fauna in a particular type of valley water body is also influenced by its origin. For example, the faunas of the oxbow lakes and riparian pools would have many characteristics in common, as these two types of water body can be characterized as originating in the river. As many as 61 species common to the valley water bodies and the Krąpiel River were noted. In the interactions between the valley water bodies and the river, the direction of migration from the former to the latter was clearly predominant. Migration in the reverse direction, from the river to the valley water bodies, took place to a far lesser degree. CCA analysis of landscape variables showed the influences of certain landscape parameters on water mites. These should be regarded as indirect influences, but as a consequence of their effects, they influence the formation of specific types of Hydrachnidia assemblages.