Helping insects overwinter in the garden
Insects have three options for surviving winter cold: migrate, die but leave behind eggs that hatch next year, or go into some form of hibernation in a safe place. We can help them survive in the garden by increasing the number of places they can use. There are many ways to do this through garden management, but buying or building your own ‘bug hotel’ has become an increasingly popular way to help with overwintering and encourage more garden biodiversity, by attracting bees, other insects and small animals. Bug hotels come in all shapes and sizes, from shop brought models the size of birdboxes to structures made from stacks of pallets, but care has to be taken to make sure they are fit for purpose.
Getting it right when buying a bug hotel
When you buy a bug hotel, you don’t have control over the design or materials. Also, many are made with more of a focus on their appearance rather than the needs of insects. There is a lot of advice on good design now available online and here are some of the important things to look out for, which we have illustrated using a bug hotel we brought and tried out.
Example of a poorly designed and constructed ‘bug hotel’ we brought, showing things to avoid
A common problem with these products is poor quality preparation of the bamboo stems and drilled holes in wood used to attract bees. When buying one, check the tubes are not blocked (bamboo has a series of chambers along the stem and badly chosen sections do not provide the depth needed by insects) and make sure the ends of the bamboo and the drill holes have been cleanly cut. If they have splinters inside, like the one we brought, they can damage the wings of an insect inspecting the hollow and are very unlikely to be used. If you do have one like this, you can replace those parts with well-prepared pieces instead.
Some features like pine cones look good, but are of very limited use for most insects. It’s also important to avoid bug hotels that contain plastic elements as plastic can trap moisture and encourage mould growth which can cause disease.
Bug hotels, like birdboxes, have to be maintained. Keeping the roof in good condition is very important to avoid letting in rain, which can also encourage mould, and parts that crack (e.g. between the drilled holes) need to be replaced as they can allow the spread of parasites.
Getting it right when building a DIY bug hotel
Making your own bug hotel offers a great opportunity to be creative and use up a wide range of spare materials you have lying around. There is lots of useful advice on how to do it available online. Building one can provide an excellent space not only for insects, ranging from solitary bees to ladybirds, and woodlice, but even provide a safe refuge for hedgehogs, frogs, toads and newts!
A homemade bug hotel can be as simple as stacking small piles of dead wood, stones, and dry leaves around the garden. Depending on where you place them, you can attract different creatures: many insects and other animals prefer cool and shady conditions, while bees prefer a place in the sun.
If you have the materials available, you can make a more complex bug hotel using old bricks and tiles to build the base, sides and roof, and filling the gaps with materials such as leaves, moss, twigs and logs.
The materials you use can also be tailored to attract different creatures. For example, bamboo sticks or hollow plant stems may be used by solitary bees, piled pots, rocks and tiles can attract amphibians, and dry leaves and twigs are a favourite of ladybirds. Just remember, when making any bug hotel it is essential to include a roof to keep the rain out.
For more information on making the most out of your bug hotel try ‘The Entomologist Lounge’ website where there is an article on “Insect Hotels: A Refuge or a Fad?”. Many organisations like the RSPB, the Eden Project and Buglife provide advice on bug hotels and the many other ways to encourage insects in your garden.
Thanks for reading. As explained in our article last month on providing water for birds and bees, enhancing biodiversity through wildlife gardening is a part of the development of a ‘Green Plan for Watlington’, along with the hedgerow survey and other projects.
Eliza Naismith and Iain Naismith
Watlington Environment Group