Last week, I led a group of students and postdocs from the Entomology Department at NC State on an expedition to collect bees at the nearby JC Raulston Arboretum. We’re working on a project to investigate how urbanization affects the native bee community and their health.
The Arboretum was a bee paradise! We saw over 20 different species of native bees in the course of an hour. Then a tussle happening mid-air caught our attention. At first we thought we had observed a pair of bumblebees mating in mid-air. Only later, when these insects landed on a nearby leaf did we realize we were witnessing predation in action!
Above is a picture of a robber fly, spectacularly mimicking a bumblebee (left), and eating a real bumblebee (right). Unlike vertebrates, insect predators take a long time to consume their food, making it easier for us to see predation in action. Robber flies inject saliva into the body of their prey to paralyze them. Then, these predatory flies slowly degrade and suck all the tissues from their victim-meal. Predation is one of the many species interactions that you can observe in your garden!
Robber flies are natural bee predators and help keep bee population sizes in balance. However, human actions are driving bee population declines around the world. Bees are dying as a result of the combined effects of pathogens, pesticides and habitat degradation. If you would like to learn how to help out these important pollinators, consider creating a pollinator garden at home. For more information, please visit the Xerces Society or Debbie Ross’ website.
Margarita M. López-Uribe is a postdoctoral researcher at North Carolina State University. She is broadly interested in understanding the evolutionary process behind bee population declines. To learn more about her research check out her website.
Great shot!