Bumble bee visiting wood cranesbill
by Soininen et al.
Plants and their insect pollinators have coevolved. Insects respond to plant cues such as flower size and colour. Pollinators compete for pollen and nectar, but behavioural and morphological differences between pollinators allow for coexistence of different pollinator species. Honeybee (Apis mellifera) is an introduced pollinator species in northern Europe. Honeybees and the native pollinators visit the same flowers and may compete for resources instead of sharing. Therefore, honeybees may affect native pollinator species negatively.
Diverse plant communities support many pollinator species. Diversity of a plant community consists of differences between species and within species. Within plant species genetic diversity could promote more diverse pollinator community.
In this study we investigated the role of genetic diversity within a single plant species, wood cranesbill (Geranium sylvaticum), on pollinator behaviour. We did this by measuring pollinator visitation rates on wood cranesbill in an experimental field. In the field we had planted different genotypes of wood cranesbills. We tested the effect of honeybees on native bumblebee visitation rates. We compared visitation rates in the presence of a honeybee hive to when the beehive was removed from the field. We show that competition with honeybees reduced visitation rates by bumblebees, but not by other native pollinator groups. Bumblebees preferred some wood cranesbills genotypes over others in the absence of honeybees, which they did not prefer in their presence. Honeybees visited the wood cranesbills flowers readily and did not prefer any particular genotype. Our study shows that within plant species genetic diversity affects bumblebee behaviour. Furthermore, honeybees affected bumblebee behaviour, raising concern of the effects of beekeeping on native pollinators.
Read the scientific paper in JPE.
No comments:
Post a Comment