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Bumblebee Conservation Trust: A brief guide to bee nest boxes
Bex Cartwright, our Making a Buzz for the Coast Conservation Officer, has written this handy guide on how to create or choose a suitable bee box to make a perfect home for solitary bees in your garden!
Siting your bee nest box
To maximise the chances of your bee nest box being occupied, careful siting is important.
- Position your nest box in full sunshine so facing south east or south
- Place the nest box at least 1 metre from the ground
- You can place your nest box near vegetation but ensure that no vegetation will obscure or shade the nest entrances
- Position the nest box in a stable, fixed position that will not sway in the wind or be easily knocked or dislodged.
- Remember, one of the reasons for having a bee nest box is so you can observe the fascinating activities of the bees visiting your garden so make sure it is somewhere you will see it regularly.
Things to consider when choosing or creating a bee nest box
If you are thinking of creating a new bee nest box or buying one of the many commercially available nest boxes there are a number of things to consider. Many are expensive and some are poorly-designed. Some of the most commonly encountered issues are:
- The length of the nesting tubes or drilled holes is not sufficient. Look for a nest box with nesting tunnels 15cms (6 inches app.) in length as a minimum.
- The diameter of the nesting tubes are often too wide. This is because houses manufactured abroad are built to attract larger species than those we have in the UK. It is beneficial to provide a range of diameter nesting tubes as this will attract a range of different species. Provide holes of between 2-10mm in diameter.
- No protection from wet and windy weather. Ideally the bee house will have a small overhang to prevent nesting tubes becoming damp. To some extent this can be alleviated by careful placing of the bee house. Somewhere sheltered but not shaded is ideal.
- Avoid the use of plastic straws or containers. Plastic and other ‘non-breathable’ materials prevent the movement of air and moisture and can encourage damp and condensation leading to fungus and mould. This will destroy eggs and larvae.
- In general tunnel and tube entrances should be smooth and free of splinters although some species will clean out and ‘tidy-up’ a tube before nesting.
- Nesting tunnels and tubes should have a solid back. Bees will not use nesting tubes which are open at both ends.
- The nesting tunnels need to be accessible and removable so that the contents can be examined, cleaned and periodically replaced. The most successful bee nest boxes are those that are well-managed.
Which bee species will the nest box attract?
The most common resident of garden bee nest boxes is the Red Mason Bee (Osmia bicornis), this species flies in early spring. Later in summer your bee nest box may also attract leafcutter bees such as Patchwork Leafcutter (Megachile centuncularis) (image above) and Willughby’s Leafcutter (Megachile willughbiella). These species play host to cuckoo bees Coelioxys, also known as ‘sharp-tailed bees’ (image right), fascinating bees which lay their own eggs in the provisioned leafcutter nests. Smaller bees such as Harebell bees (Chelostoma sp.) and Masked or Yellow-faced bees (Hylaeus spp.) are also attracted to nest boxes
A range of solitary wasps may also use the nest box, these will act as a great natural pest control in your garden, collecting flies, small caterpillars and aphids to provision their nests.
Managing your bee hotel
Periodic maintenance and cleaning will result in a more successful nest box and a healthier population of bees in your garden. With no cleaning, fungi, debris and parasites tend to build up which can be damaging to the bees.
- Bring your nest box into an unheated shed or garage during the autumn and winter to protect it from damp and wet weather. If you don’t have either then a porch or any covered area will do. It is damp not cold that destroys larvae. Not only will this protect the larvae and adult bees waiting to emerge in the spring but it will mean that your nest box will last longer. You can place the box outdoors in the spring, from March onwards.
- If you notice birds predating your nest box or removing nest tubes (woodpeckers and tits often do this) then you can place a piece of mesh or chicken wire across the front. This does not appear to deter the bees.
- If your nest box is built of stacked & routed wooden sheets or you use paper nest tube liners you can clean it out in winter, remove the cocoons (image left) and store them until spring.
- At least every couple of years replace all of the tubes and blocks in the nest box with fresh ones. In spring leave the old tubes in an upturned box or bucket on the ground with a hole at the top (bees naturally orientate towards light) so that the previous year’s bees can emerge but so that they won’t reoccupy the old tubes.
For further information on all of the above Marc Carlton of ‘The Pollinator Garden’ has produced an excellent guide to ‘Making and Managing a Bee Hotel’. A pdf. version can be downloaded from www.foxleas.com
George Pilkington also has a fantastic website and blog ‘Nuturing Nature’ www.nurturing-nature.co.uk which has a wealth of information on managing bee houses.
For photos and more information about the bees and wasps that are attracted to nest boxes the website of The Bees, Wasps and Ants Recording Society ‘BWARS’ is very helpful www.bwars.com