Side effects of commercial Bacillus thuringiensis insecticides on micro-colonies of Bombus terrestris

contribution to session II Bumblebees and other bee specie

Evaluation of side effects of commercial biological pesticides on the beneficial insect, Bombus terrestris

contribution to session II Bumblebees and other bee specie

Commercial bumblebee hives to assess an anthropogenic environment for pollinator support: a case study in the region of Ghent (Belgium)

Anthropogenic changes of the environment influence the distribution and abundance of pollinators such as bumblebees and have been proposed as one of the main causes in their worldwide decline. In order to evaluate the impact of expanding anthropogenic landscapes on supporting pollinator potential, reliable tools are needed. Bombus terrestris is one of the most abundant bumblebee species in Europe, and these bumblebees are known as generalist pollinators of not only wild flowers in nature but also of crops in agriculture. For more than two decades, these bumblebees have been commercially mass reared for biological pollination in greenhouses. In this project, we placed commercial hives of the bumblebee B. terrestris containing one queen and 40 workers, in three different locations in the region of Ghent (Belgium), and the performance of these hives was followed during a 4-week period in spring 2012. In parallel, we determined the floral richness and diversity index in the chosen study sites. The sites consisted of a rich urban environment with patchy green areas opposed to an urban environment with poor landscape metrics; a third rural study site showed average positive landscape metrics. The results demonstrated that the hive biomass and numbers of workers increased significantly in the rich compared to the poor environment, providing a mechanism to discriminate between study sites. In addition, the bumblebee-collected pollen showed that the flowering plants Salix spp. and Rosaceae/Prunus spp. are dominant food sources in all anthropogenic environments during early spring. Finally, the results are discussed in relation to the optimization of the experimental setup and to the use of commercial bumblebee hives in assessing local pollinator support within any given environment

Entomovectoring in plant protection

This paper gives an overview on the unique concept of the entomovector technology to employ pollinating insects, including honey bees and bumble bees in the context of biological control of insect pests and diseases. After a brief introductory description, the multifaceted aspects of this intriguing technology are highlighted by describing the most significant results and achievements of research groups around the world concerning: (1) the importance of vector selection, as this determines the transport efficacy of biocontrol agents into the crop and is influenced by the vector-plant interactions, (2) the different potential biocontrol agents used so far, (3) the significance of the diluent and formulation for an increased vector loading and transport, (4) the different dispenser types developed over the past 20 years, and (5) the safety of this technology to the environment and humans. For all these interactions, we identify in a critical manner the limitations and the successes obtained so far. The needs for further research are also discussed to increase the potential of the entomovector technology in practical use