Meeting Abstract

18.7  Saturday, Jan. 4 11:45  Vibrating Bees: Behavioral Changes in Buzz Frequency SWITZER, C.S.*; COMBES, S.A.; Harvard Univ., Cambridge; Harvard Univ., Cambridge cswitzer@fas.harvard.edu

Multiple bee taxa have evolved the ability to collect pollen by shaking it from plants’ anthers. While grasping or touching the anthers, bees vibrate their bodies using their flight muscles, without flapping their wings – termed “buzz pollination”. Bumblebees perform buzz pollination, but honeybees do not. Many plants depend almost entirely on buzz pollination. Because of these plants’ tubular anthers and/or difficult-to-reach pollen, honeybees struggle to pollinate them. Behavioral aspects of buzz pollination in bumblebees have not been fully characterized. We set out to answer the following questions: 1) Can bumblebees change the frequency of their buzz? 2) Do bumblebees’ buzz frequencies differ on plant species flowering throughout the foraging season? We surveyed a variety of plants and used a microphone to measure the pollination buzz frequency of over 300 wild bumblebees (Bombus impatiens). We captured and measured the frequency of the bees’ irritation buzz, which is used as an alarm signal or to help the bee escape tight places. We gathered morphological data and weather conditions, before marking and releasing the bees. To determine if bumblebees can change their buzz frequency, we compared irritation and pollination buzzing. We found that bees can buzz at a much higher frequency than their pollination buzz. To determine if buzz frequencies differ on different plants throughout the foraging season, we compared the bees’ buzz frequencies among plants. While accounting for differences in time of year, temperature, time of day, and bees’ size, we found significant differences in buzz frequencies. This suggests that bumblebees may have more control over their indirect flight muscles than previously thought. It also shines light on the factors that may play a role in bumblebees’ pollination behavior.