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Red Mason Bee

Red Mason Bee – Osmia bicornis (Male)

Osmia bicornis – male

I really look forward to seeing these handsome little chaps each year. The Red mason bee Osmia bicornis is a species of solitary bee often seen in spring and early summer, usually from late March to early June, although this year due to the very cold weather they’ve been a little late. The males appear first, up to two weeks before the females and so like the male pictured above they spend a fair bit of time preening and sunbathing before the girls arrive.

These are extremely friendly bees. The male has no sting and the female will only sting if handled very roughly and even then the sting is very mild in comparison to the sting of a wasp, bumblebee or honey-bee. So these are good bees for children to get up close to and observe.

After mating the males soon die and the females hunt for a suitable nesting site, generally preferring to nest in preexisting hollows like plant stems or old beetle holes rather than excavate their own. Subsequently they do nest in some rather odd places like key holes, air bricks, empty snail shells etc. Both sexes are covered in dense gingery hairs, however the male is smaller than the female and has white tufts of hair on its face which remind me of a large white moustache. The female is generally a little larger and broader and can be identified by her black head and facial horns.

Osmia rufa can be encouraged into gardens by putting out artificial nest sites. You’ve probably seen fancy bee hotels for sale online or in garden centres but it can be a simple enough task to create your own from a collection of cut bamboo canes. These should be placed in a group, in an open position 1 to 2 metres above the ground against a south facing wall or fence. The brood cells are created in a linear fashion and are lined, separated and then capped off with a plug of mud, which is where the name ‘mason’ comes from. Male larvae are therefore placed nearest the final cap so that they can emerge first next spring.

Although described as a solitary bee, this bee is rather gregarious and so once a female has found your artificial nest, others usually follow. Go on build one you know it makes sense.

Red mason bees are useful pollinators of fruit trees like Apple and Pear and for this reason are sometimes called Orchard Bees. So give them a little thought the next time you are crunching into a crisp red Discovery or tucking into a tart Egremont Russet.

By the time you’ve read this I’ll be on my way to the island of aphrodite to visit the aged parents and to enjoy some sunshine. Whilst there I’ve been asked by Eddie John of the Cyprus Butterfly Recording Scheme (CBRS) if I could take some photographs of insects for a book about the Wildlife of Cyprus. So who knows, maybe my next post will feature something exotic.

2 Comments Post a comment
  1. Lisa Vankula-Donovan #

    Wow! My lack of knowledge would have. Me believe this was just a bumblebee. Interesting that the males get to live a little before the females come and they die! Also interesting is how they out the males closest to the entrance/exit. Clever little things!

    June 27, 2013
  2. I would imagine you get quite a few interesting species of solitary bee in Australia. I bet it is a fantastic place for insects. Love to visit one day.

    June 30, 2013

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