Varroa mite hitching a ride, staying alive
In the off chance you haven’t seen this video, prepare to be amazed. After watching it dozens of times, I’m still mesmerized. The video, shot by David Peck of Cornell University, shows a Varroa mite hanging out on a composite flower. She is alone and can’t see. But as soon as a honey bees lands on her flower, she recognizes instantly that her flight has arrived. She hurries up the boarding ramp (rear leg) and nestles into the protected space between thorax and abdomen. With her seat back and tray table in the upright position, she awaits take off.
The video is part of a study by David T. Peck, Michael L. Smith, and Thomas D. Seeley who were trying to determine whether the parasitic mite Varroa destructor could spread from colony to colony by infesting foragers at feeders and flowers. The paper, “Varroa destructor Mites Can Nimbly Climb from Flowers onto Foraging Honey Bees” is available to read for free and contains lots of information about how mites detect the bee and ultimately move into their new home. Their methods are so clearly explained that you could easily try this at home.
A method of Varroa mite transmission
I was particularly interested in this paper because last year I wrote a post about mite transmission between colonies called, “7 methods of Varroa mite transmission. At the time, I wrote:
Mites on flowers. Of all the possible methods of mite transmission, this one seems the least likely. Mites are attracted to the pheromones of bees, so it seems far fetched that a mite would jump off a bee onto a flower and wait for another bee to arrive. However, if a Varroa-laden bee lands on a flower and begins to groom, it is possible that she will dislodge a mite. If so, that mite has no choice but to wait for another honey bee to come along and give her a lift. Surely this happens from time to time, but it’s probably not a major means of transmission.
The authors do not dispute my take on this. In fact, they write, “It is not yet clear how significant this mode of transmission may be for mite spread between colonies because little is known about how frequently mites wind up on flowers. Our study examined only the transfer of mites from flowers to bees but not from bees to flowers.”
How often does it happen?
As you can see, we still don’t know exactly how mites get on flowers or how frequently. Still, mites apparently have all the know-how when it comes to hitching from a flower, making it appear to be a tried and true method. Peck et al. suggest that mites on flowers are a possible, if unproven, mechanism for mite transfer across long distances even when honey bee movement is restricted.
At any rate, enjoy the video. The first run-through is in real time and then it plays at 40% speed so you can see it better. I will warn you in advance: the video makes me itch. Every time.
Honey Bee Suite
Peck DT, Smith ML, Seeley TD (2016) Varroa destructor Mites Can Nimbly Climb from Flowers onto Foraging Honey Bees. PLoS ONE 11(12): e0167798. doi:10.1371/journal.pone.0167798