Urbanisation is an expansive process and a majority of insects live in human-modified areas. At the same time, a decrease in pollinator species richness and abundance has recently been observed in Europe, which in turn may have serious ecological and economic consequences. This study investigates the abundance, species richness and functional traits of wild bees in urban city parks in comparison to natural areas. The aim of this research was to assess the potential conservation values of urban green areas for bees. The present study demonstrates that a large and diversified city park may be a favourable habitat for bees, comparable to the natural fauna both in terms of the number and abundance of bee species. However, the study also showed that there were differences in the occurrence of species with different functional traits in the city parks investigated and in the natural landscape.
The knowledge and conservation of diminishing valuable habitats in agricultural landscapes are of key importance in saving declining farmland biodiversity. One of these habitats is the traditional orchard whose role in supporting birds is still poorly known, especially in winter. We counted birds in 106 orchards differing in management intensity (abandoned, traditional, and intensive) during December 2009 and January 2010 in Wielkopolska, western Poland and measured site characteristics and composition of surrounding landscapes for every orchard. Old abandoned and traditionally managed orchards had significantly higher bird species richness than intensive ones. Irrespective of orchard type, bird species richness as well as density were positively influenced by the cover of unmown herb layer in orchards and tree diversity. Tree and fruit densities positively affected bird species richness and density mainly in abandoned orchards while in other orchard types the effect of these variables was less pronounced. Land cover diversity in a landscape had a positive effect on species richness and density mostly in abandoned orchards and we believe that this effect reflects the elevated utilization of such orchards by birds from the surrounding landscape. Thus, abandoned, as well as traditionally managed orchards seems to be especially important habitats that offer food source and refuge for wintering birds and should be protected. We propose to diversify fruit production by planting various tree species, leaving part of the herb layer unmown and several trees unharvested in intensive orchards in order to improve suitability of modern orchards for birds.
-An efficient antioxidant system is of particular importance for insects whose high metabolic rates promote increased formation of reactive oxygen species (ROS). The amount of ROS can be additionally increased by environmental factors. This study investigates the ability of red mason bees (Osmia bicornis L.) to inactivate free radicals during insect development. Both male and female bees were studied, from the larval to the active imago stage. The activity of four antioxidant enzymes, superoxide dismutase, catalase, peroxidase and glutathione Stransferase, was measured; and glutathione content and total antioxidant status were determined. The highest values of the examined parameters were found in feeding stages-in larvae and in active imagines of both genders. Significant differences between genders were noted mainly in catalase activity, which was lower in overwintering imagines and active females than in males. Most differences were observed between females and males after emergence.antioxidants / pollinating insects / insect metabolism / development / enzymes
-The global loss of bee diversity and abundance is a central issue in conservation biology. There is increasing evidence that cities may play an important role in bee conservation, although urbanization may also have negative impacts. Here, we investigate individual body size variation and wing asymmetry (based on 11 traits) in the solitary bee Anthophora plumipes along a rural-urban gradient in Poland. The body size of captured individuals did not show any changes along the gradient. Directional asymmetry was present, since differences between sides in 10 out of 11 traits deviated significantly from zero, with the right-side wing traits being generally larger. In contrast to our expectations, the forewing was more asymmetric in rural than in suburban and urban areas. Similarly, the absolute asymmetry of 11 wing traits (i.e. pooling differences but ignoring direction) was also significantly greater in rural than in suburban and urban landscapes. Since asymmetry may be attributed to environmental pollution and food shortages, we conclude that the urban landscape provides bees with habitats of higher quality and thus should be considered as an important habitat for bee conservation.hymenoptera / Apoidea / bees / city / directional asymmetry
The influence of simulated climate change on body weight and depletion of fat body reserves was studied during diapause in the European solitary bee Osmia rufa L. (Hymenoptera: Megachilidae). Insects (females) were reared and collected from outdoor nests from September to March. One cohort of females was weighed and dissected immediately for analyses, whereas another cohort was subjected to simulated warmer temperature (15°C for 7 d) before analyses. A gradual decline in body mass and fat body content was recorded with declining temperatures from September to January in female bees from natural conditions. Temperature increased gradually from January to March with a further decline in body mass and fat body content. The fat body development index dropped from five in September-October (≈ 89% individuals) to four for the period from November to February (≈ 84% individuals) and further to three in March (95% individuals) before emergence. Simulated warmer winter temperature also resulted in a similar decline in body weight and fat body content; however, body weight and fat body content declined faster. The fat body development index dropped to three in December in the majority of individuals and continued at this level until March just before emergence. Taken together, our data indicate an earlier depletion of fat body reserves under simulated climate change conditions that may impact ovarian development and reproductive fitness in O. rufa.
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