by Sandy Garland
The other day, Berit sent me a photo of a bumble bee carrying another one. She wondered about this behaviour: why? how?
I posted her cell phone photo on Facebook, in the Insects and Arachnids of Ontario group, and was astonished at the response. This was not a bumble bee at all! It was immediately identified (by Brian Robin – thanks!!) as a robber fly.
Jeff Skevington (an entomologist at Agriculture and Agri-food Canada) added: “The robber fly looks like Laphria thoracica to me. They use their camouflage as protection from predators but also in a more aggressive way to hunt bumble bees. Nice that you got to see this!”
Try Googling Laphria thoracica and you will be amazed at how much this fly looks like a bumble bee. In the photo below, you can see that the robber fly’s eyes are too large for a bee, and I assume it has quite different mouth parts, but those are not features easily seen while these creatures are flying around.
Kudos to Berit for her observation skills and quick work with her cellphone camera.