wild bees and native bees

Mites on a bumble bee

Yesterday I spent some time deleting photo files from my computer. I was just about to trash this one when I saw two odd-looking dots on the back of the bumble bee. When I enlarged it, I decided the dots looked like mites. If I had noticed them at the time, I would have tried for a better shot. Instead, this is what I have:

Bumble bee 1 June 19 Olympia

Two mites on the thorax of a bumble bee. Photo taken June 2012 near Olympia.

It turns out these mites are not uncommon. They are most likely in the genus Parasitellus and can be seen singly or in large groups on the thorax of bumble bees.

From what I’ve pieced together, these mites live in the nests of bumble bees and disperse by hitching a ride on foraging bees, preferably queens. The phoretic stage seen in the photo is a deutonymph—one of the larval stages—not a mature adult.

The mites spread when robber bees or cuckoo bees enter the nest, when deutonymphs are left on a flower and hitch a ride on a different bee, or when the mites simply switch from one bee to another. Occasionally they are found in the borrows of small animals and even in honey bee hives, where they do not survive.

It is unclear if the mites do any harm to the bumble bee. In fact, some sources suggested the mites may be predatory on other mites and thus be beneficial to bumble bee colony health.



  • Thanks for your many educational and interesting posts. My hives are across a road from an alfalfa field and I will be looking for the bees there next summer.

  • I came across your wonderful honey bee site and have gained much wisdom.

    I am just about to start doing talks for WI and other organisations to spread the word and the love for our bees, which we can all help with. I have kept bees for 5 years in UK and read almost the whole library of books. My husband says I have Bee Fever, I say Bee Love, either way I want to help the plight of the bees and spread the Bee love.

    I was hoping you would allow me to use some of your photos to add to my own collection which I am putting together for my talk and slide show presentation. Spread the love!

    Thank you buzz buzz Totty Dorset, UK

    • Totty,

      I glad people like you are working on behalf of the bees. You may use photos as long as you give credit to the photographer and add a link back to my site. Thank you.

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