507 research outputs found
A failed invasion? Commercially introduced pollinators in Southern France
The natural diversity of Bombus terrestris subspecies could be under
threat from the commercialisation of bumblebees. Therefore, to determine whether
commercially imported bumblebees are able to establish and spread, we carried out
long-term observations of bumblebees in southern France. Our surveys occurred before,
during, and after the importation (between 1989 and 1996) of thousands of colonies of the
Sardinian subspecies B. t. sassaricus. Queens and males of B. t.
sassaricus were observed foraging outside commercial greenhouses in 1991, 1993,
and 1994 and feral workers were observed foraging on native vegetation nearly two years
after the importation of B. t. sassaricus ceased. However, no B.
t. sassaricus, or F1 hybrids were observed after 1998. We conclude that
B. t. sassaricus remains inconspicuous in France and competition from
the three native subspecies may have prevented it from becoming invasive. However, genetic
interference through introgression cannot be ruled out
New records of bees (Hymenoptera: Apoidea) from the Maltese Islands
A total of 95 bee species have been recorded from the Maltese Islands (central Mediterranean Sea). The aim of the present note is to report newly recorded species within the study area. A total of nine new species belonging to four families are recorded here: Andrenidae (1 species), Apidae (1 species), Halictidae (5 species), and Megachilidae (2 species)
Pheromonal and enzyme genetic characteristics of the Bombus lucorum species complex in northern Europe
Spatial and temporal distribution of the species in the Bombus lucorum species complex, B. lucorum (L.), B. cryptarum (Fabricius) and B. magnus Vogt, were studied in Finland. Morphological distinction between the species is not as clear as in Central Europe, but B. lucorum can be distinguished from the other two with the help of enzyme genetic markers. B. lucorum is the most common of the three species in most of Finland, and B. cryptarum is abundant in the southwestern coastal area and in northern Lapland. B. magnus was only rarely found among the spring queens in southwestern Finland, and its range possibly restricts to southern and central parts of Finland. A comparison of the chemical composition of the male labial glands and enzyme genotypes shows that males produce species-specific marking pheromones
SAPOLL : A cross-border action plan for wild pollinators
Wild pollinators in the France-Wallonia-Vlaanderen cross-border zone represent a valuable but highly endangered resource. In order to protect these pollinators, it is essential to set up a cross-border organization that enables coordinated actions and synergies between regions. Indeed, isolated actions on both sides of the border are unlikely to lead to the sustainable management of this indispensable resource. The challenge is huge because wild pollinators, wild bees, syrphs and butterflies, are essential to maintaining agriculture and ecosystems in our regions. In order to meet this challenge, the SAPOLL project initiates the implementation of a cross-border action plan for wild pollinators with the actors from Wallonia, Flanders and northern France. This plan is the initiator of actions in favor of pollinators, bringing the necessary scientific, didactic and applied context to citizens, decision-makers, entrepreneurs or enrionmental managers. It is also adapted to the regional context of each area. The action plan, which is co-built with the partners in the cross-border territory. The SAPOLL project also organizes activities that aim to homogenize and share scientific knowledge, awareness-raising experience and naturalistic competences
Ensuring access to high-quality resources reduces the impacts of heat stress on bees
Pollinators are experiencing declines globally, negatively affecting the reproduction of wild plants and crop production. Well-known drivers of these declines include climatic and nutritional stresses, such as a change of dietary resources due to the degradation of habitat quality. Understanding potential synergies between these two important drivers is needed to improve predictive models of the future effects of climate change on pollinator declines. Here, bumblebee colony bioassays were used to evaluate the interactive effects of heat stress, a reduction of dietary resource quality, and colony size. Using a total of 117 colonies, we applied a fully crossed experiment to test the effect of three dietary quality levels under three levels of heat stress with two colony sizes. Both nutritional and heat stress reduced colony development resulting in a lower investment in offspring production. Small colonies were much more sensitive to heat and nutritional stresses than large ones, possibly because a higher percentage of workers helps maintain social homeostasis. Strikingly, the effects of heat stress were far less pronounced for small colonies fed with suitable diets. Overall, our study suggests that landscape management actions that ensure access to high-quality resources could reduce the impacts of heat stress on bee decline.info:eu-repo/semantics/publishedVersio
Quantitative AFM analysis of phase separated borosilicate glass surfaces
Phase separated borosilicate glass samples were prepared by applying various
heat treatments. Using selective chemical etching we performed AFM measurement
on the phase separated glass surfaces. A quantitative roughness analysis
allowed us to measure precisely the dependence of the characteristic size of
the phase domains on heating time and temperature. The experimental
measurements are very well described by the theoretically expected scaling
laws. Interdiffusion coefficients and activation energy are estimated from this
analysis and are consistent with literature data
Extreme Food-Plant Specialisation in Megabombus Bumblebees as a Product of Long Tongues Combined with Short Nesting Seasons
© 2015 Huang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. http://creativecommons.org/licenses/by/4.0/ The attached file is the published version of the article
Short communication: First data on the prevalence and distribution of pathogens in bumblebees (Bombus terrestris and Bombus pascuorum) from Spain
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