The world of the solitary bee home…

During the last few weeks I have made a fair few bee bundles at community events – St. Andrews Flower Festival in Chinnor, at Wycombe Rye for the Chilterns Celebration event and at Coleshill Common on their Wildlife Explorer Day. These little bundles are easy to put together and a great way to talk about the many types of bee that live around us, gathering pollen and laying their eggs in holes in walls, in the soil and in hollow sticks. Most people – most children –seem to know quite a lot about bees. There aren’t just honey bees but bumblebees and solitary, or wild, bees. However, I discovered that quite a few people aren’t really sure about what’s really going on in those twigs and holes. So here’s a quick guide…

There are quite a few species that tend to make their homes in the drilled holes and sticks in bee homes like the one pictured. If the end of the hole is plugged with mud, it’s probably the red mason bee (Osmia bicornis), although there are other Osmia species that might be using them too. The tiny holes that look like they have a thin piece of paper over the end are probably being used by yellow-faced bees (Hyleaus communis), and again, there are several species of this bee. However, they might also be being used by solitary wasps, generally very small and black. These wasp species can be very difficult to identify but if they are tiny and you can’t see any yellow markings, they are probably wasps. The big give away is if you see them carrying aphids or spiders into the hole as this is what they feed on.

Okay, so what’s going on in there?

Well, the female bee or wasp takes food into the hole – pollen for bees, aphids and spiders for wasps. When she has enough food deposited, she lays an egg on the food store. She then closes these into the cell by building a wall. This might be from mud carried in or she might scrape the sides of the stick and make a papery substance to close it off. So inside there is a row of cells with food and an egg in.

When the eggs hatch, the larva has food ready to eat before it becomes a chrysalis. Depending on the species and the time of year, they can stay as a chrysalis for a few weeks or might even overwinter like this before emerging as adult bees and wasps. Inside the chrysalis they are slowly developing into adult bees and wasps

The bee nearest the exit is the first to emerge and it is the males who are out first as well, as they wait around the entrances for females to come out.

However, it is not uncommon to have lots of parasites living in the cavities…this is quite normal and part of the interacting web of organisms that are carrying on their lives around us. However, that might be topic for another update…

Katie Horgan, Rough Around the Edges Project Officer, BBOWT

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Photo credits: all images are Katie Horgan

If you want to find out more about solitary bees, Steven Falk is the UK expert. His Field Guide to the Bees of Great Britain and Ireland is the best book I’ve seen about them and he has resources to help identify them:

http://www.stevenfalk.co.uk/bees