Characterizing buzz pollination provided to cranberry flowers by visiting bees in central Wisconsin cranberry marshes

Managed honeybees (Apis mellifera) are often employed by Wisconsin cranberry (Vaccinium macrocarpon) growers to improve crop yields, however honeybees are unable to perform buzz pollination. In order for cranberry pollen to be released, the anthers must be vibrated at a specific frequency, known as buzz pollination. Bumble bees (Bombus spp.) can buzz pollinate and are more efficient pollinators of cranberry than commercial honeybees but are not as commonly utilized for commercial pollination. This study will determine the frequency and duration of buzz pollination provided to cranberry flowers by visiting bees in relation to the age of the cranberry flowers visited and the resource (pollen or nectar) being foraged for. Data will be collected during the 2025 bloom period (June-July) using video and audio recordings to record the foraging behavior of flower visiting pollinators. The videos will then be annotated to document flower age, pollinator identity, floral resource foraged for, and frequency and duration of buzz pollination. We expect that, because buzz pollination is only associated with pollen collection, only pollen foraging bumblebees will buzz pollinate when visiting flowers. We also expect that bumble bees will spend a longer time buzz pollinating cranberry flowers when flowers are younger and presumably have more pollen available for collection. By increasing our understanding of pollinator foraging behavior in cranberry, growers can make more informed decisions regarding pollinator management on their farms.