Pollen Gathering

My research in this area is currently in press in the Journal of Hymenoptera Research, "A review and updated classification of pollen gathering behavior in bees (Hymenoptera, Apoidea)" doi: 10.3897/jhr.@@.32671

How a bee gathers pollen depends on many factors, including the structure of the host flower, the location of the pollen, and the behavioral and evolutionary limitations of the bee. I am interested in documenting the different types of pollen gathering behaviors and how they evolved. In particular, I am exploring the link between different floral and pollen morphologies and how they affect pollen gathering behavior in different bee species. ​
Active vs. incidental pollen gathering

Active pollen gathering occurs when when pollen is the primary objective or when nectar (or oil) and pollen are co-objectives. Active pollen gathering can be broken down into six types: scraping with the extremities, buzzing, rubbing with the body and/or scopa(e), tapping, rubbing with the face, and rasping. Each type is broken down below. 
Incidental pollen gathering occurs when pollen accumulates on the body, EITHER when a bee nectaring OR performing a primary pollen gathering behavior and pollen accumulates on non-target areas of the body. 

The different types of active pollen gathering behavior:
  • ​Scraping with the extremities: use of the legs or mouthparts to remove pollen directly from anthers, or, less commonly, to glean pollen from flowers. This is the most basic and primitive mode of pollen gathering. The video shows two bees, an Andrena chlorogaster and a Lasioglossum (Dialictus) species, gathering pollen by scraping with the extremities and biting with the mandibles. 




  • Buzzing: use of the flight muscles to vibrate a flower to assist with pollen release. This video shows a Bombus impatiens buzzing in a rig specifically designed to capture the buzzing noise (thanks to Avery Russell for use of the video). Next, a Bombus species is buzzing an open flower, alternating with scraping with the forelegs as it wades over the open flowers. The buzzing is a bit faint in this one, so I added a red bar when it buzzes. Thanks to youtuber sigma1920HD for this video. They have many more cool videos you can see on their youtube page. 
 
  • Rubbing with the body and/or scopa(e): the gathering of pollen through  direct and more or less continuous contact with the anthers by the main trunk of the body (thorax, abdomen) and/or the scopal hairs.
  • Tapping: picking up pollen from anthers by a rapid up and down motion of  the abdominal venter.
  • Rubbing with the face: continuous and more or less direct contact with the  anthers by the face.
  • Rasping: rubbing of the thoracic dorsum against anthers, causing the anthers  to vibrate and release the pollen.