Red mason bee
Red Mason bee , image link:

Swarm season

Preparing my bees for the onset of spring, and in particular, the swarm season is my main activity right now. During the peak in May, I expect many calls from people who have suddenly found a swarm of bees land in their garden.

Early call

I was somewhat surprised to receive such a call yesterday, in mid April, still very early.

An old friend who lives nearby called me as she’d become concerned when spotting some insects flying in and out of her wall. She’d contacted a ‘pest controller’ expecting them to be wasps, on inspection, the man said they were honey bees and could be ‘sorted’ for her by just blocking up all the vent holes that they were using. She’d then contacted her building manager, as it was a new house, as she wasn’t keen on killing the bees. The next inspection confirmed the bees were entering her air vents and so it couldn’t be blocked up.
During her call, I was curious of two factors, the bees weren’t using a single entrance, and it was not sounding like a honey bee invasion.

Red mason bee heading for the air vent
Red mason bee heading for the air vent









Bee team to the rescue

As one of my bee team members Rande, lived a short distance away, she popped over to the back garden to see if she could catch a photo of one of the bees so i could try and identify it before my arranged visit later in the afternoon. With her swift action, aided by being tall and with an excellent camera phone, i could tell these weren’t honeybees, but what could they be?

Red Mason bee
Red Mason bee. photo: Rande Barrowman

Late afternoon, I was able to observe my friend’s new housemates for myself.
As she had told me, the bees were coming and going using all the vent holes along the top of her patio doors. Rande’s picture had confirmed these were Red mason bees (Osima bicornis) They can quite easily be confused with a honey bee, as in the right light they have the familiar stripy abdomen. This can get worn out, and they have longer hairs, so in the right light they look almost shiny with a ‘halo’ of fluffy almost red hairs.





Red mason bee heading for the air vent
Red mason bee heading for the air vent

Whilst watching these solitary bees coming and going, and trying to capture a good photo, I noticed bright yellow on the underbelly. This is another indicator of the species as red mason bees don’t collect pollen in sacs on their legs like other bees, but instead it sticks to her abdomen. You could enjoy watching them coming and going with various colours on their bellies! 






What next?

The life cycle of red mason bees is very short,( March to July) and as a solitary bee, all that is happening is she is laying a handful of eggs, one in each mud formed cell, along the air vent. once she’s filled the tube, she’ll disappear and the new eggs will hatch, so by July there’ll be no more bees coming and going.  As my friend wasn’t bothered by the bees living in her vents we have left them be(e).

Bee Hotel
Bee Hotel








Where do they normally live?

Being one of the most commonly found solitary bees in England, they’re often found in churchyards and old buildings, nesting in the cavities between mortar, old timber, cracks around windows and even keyholes! In a more natural environment they would nest in bramble hollow stems. They even have facial horns which they use to manipulate the mud into the cells for the eggs. The red mason bee is also one of the first to take up residence in bee hotels often put up in gardens.


If you’re worried about some unidentified bees moving into your home or garden, you can look at The Bumblebee Conservation Trust

website or if you’re local, give me a call! There’s also a fabulous Bee identification guide available from The Field Studies Council

Bee hotel at Castle Gardens, Sherborne. Dorset
Bee hotel at Castle Gardens, Sherborne. Dorset

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