Saturday, July 31, 2010

Tormented

This weary bumblebee landed on our conservatory windowledge this afternoon and began grooming. While I was photographing it a tiny pink acarine mite (which I think is Parasitellus) crawled out of the fur under the bee's wing, climbed down under its abdomen and then climbed up its thorax...

... before crawling down into the fur again between the head and thorax. The bee was clearly irritated by the mite and tried to comb it off, with no success.























Here you can see it burrowing down behind the bee's head. Opinion seems to be divided about how much damage these mites do. It may be that - like the Varroa mite that infests honeybees - some species transmit diseases between bumblebees and some species may weaken their host when they suck its body fluids through weak points in the bee's joints, where they attach themselves. Apparently Parasitellus doesn't feed on bees but merely uses them for transport between bees' nests, where it feeds on the wax of the brood cells. I suspect that pink patch on this bee's knee is another mite, tucked in between the joints in the leg. Some mite species actually enter their hosts body through the spiracles and live attached to the respiratory organs, as internal parasites. Such mites weaken their host, although their effect isn't likely to be as devastating as thick-headed flies, whose larvae live as internal parasites of bumblebees.

10 comments:

  1. I'm not generally a squeamish person but that is all pretty grim. Very grim for the bumble bee.

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  2. fascinating ,you certainly are a mine of imformation

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  3. Poor bumblebee. :( It's not as if they can go to the chemist for something for it either! I hope it was able to go about its business after resting for a while.

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  4. Yes, it is grim. Poor bumble bee.

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  5. Hi Adrian, I guess the downside of being a social insect like a bumblebee is that they tend to pass on parasites in the nest..

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  6. Hi David, I just happened to have the right book on my bookshelf (the recent New Naturalist book on Bumblebees, which even had an illustration of the mite)

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  7. Hi Lesley, it flew away again, so it still had some working life left. Workers generally only live for a couple of weeks. Old ones often have very frayed wing tips .... they simply wear out..

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  8. Hi lotusleaf, they certainly are hard working insects ....

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  9. Great close up photos Phil and well spotted.

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  10. Hi John, wish I'd got a picture of the bee trying to comb off the mite - it was clearly very agitated.... but I was too slow..

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