Bug boxes

by Richard Jones

I've always been rather sceptical about the benefits of bug boxes, ladybird and lacewing hotels...

Red-tailed bumblebee, Bombus lapidarius, on a flowerI've always been rather sceptical about the benefits of bug boxes, ladybird and lacewing hotels and other artificial constructions marketed to improve the roosting conditions for helpful insects in the garden. I was once given a solar-powered insect viewer. The idea was that sunlight during the day would power a small light at night to attract nocturnal moths to settle to be examined the next day. Unfortunately the light was so feeble it never attracted a single insect. I had better luck leaving the bathroom light on each night.

The notion of bug boxes came back to me recently when I had a quick look through the 'my garden' section of the RSPB's Homes for Wildlife web pages. Under 'homes for insects' it suggests installing or building one. Well, I've decided I am going to build one, but only along very particular lines.

Many species of solitary bees and wasps nest in tunnels bored into wood. They often use old beetle burrows, rather than digging their own. And of course leaf-cutter bees will nest in any available tube. We've got them nesting in an old bathroom overflow pipe and my parents once had them nesting in the metal tubular handle of the lawn mower. The easiest construction is to gather some short (20-30cm) lengths of bamboo cane, bundle them together with wire or shoved into an open-ended canister of some sort and place this in a sunny position against a fence, wall or tree trunk.

Solitary bees and wasps do not live in large colonies like bumblebees, honeybees and yellow-jackets (social wasps), so each burrow is used by a single female making her own individual nest. However, because nest sites are at a premium, many often nest near each other in what have been delightfully called bee and wasp villages. The different size of bamboo canes also means that they might attract a variety of species, including cuckoo brood parasites, which lay their eggs in the nests of others.

The other way to create these nesting sites is to drill holes into a dead standing tree trunk (more aesthetically pleasing than a plank of wood). The holes need to be at least 10 and preferably 20cm deep, with a diameter of 4-8mm. Mind you, if you live in Leicestershire, drill holes 15mm across and you might get the massive carpenter bee, Xylocopa violacea.

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Gardeners' World Web User 29/01/2009 at 14:30

I feel that any help we can give will go toward the diverse garden insects that we need for our gardens to blossom, I cut several logs about 12" long and 6" circumference I drill several holes of various diametres and place them at various locations throughout my garden.Its like having multiple pets without the hassle and you do not have to feed them.

Gardeners' World Web User 29/01/2009 at 16:10

I am looking to intoduce more butterflies to our garden this year, does anyone know a reputable supplier of the larve, in the uk.

Gardeners' World Web User 29/01/2009 at 16:57

hi, im ben im 13 and love to grow, i grown veg last year, i grown beans carrots and peas.i hope to grow lots more this year. do you have any advice for me on growing plants.

Gardeners' World Web User 30/01/2009 at 09:41

Reply to Weakleys. Please do not buy butterfly caterpillars to release in the garden. This is a waste of money, interferes with the local butterfly populations and may be illegal. The only sensible way to get more butterflies in the garden is to grow butterfly-attractive flowers and leave some parts of the garden to run wild for foodplants and shelter. There are plenty of butterflies about, all they need is to be able to colonize gardens which are much less intensively manicured. Captive breeding of butterflies from caterpillars can be very interesting and children especially will benefit from seeing the larvae grow and transform into adults. Kits are available from educational suppliers where no foodplant is required — artificial nutrients are supplied for the caterpillars to eat. The butterflies are usually painted ladies, Cynthia cardui, a regular migrant to the UK from southern Europe and North Africa, but which cannot survive our winters, so any release of adults into the wild will have no effect on local genetics, because they all die off each year any way. Releases of native butterflies, for conservation purposes, have to abide by a code of conduct, and licences from Natural England. Many years ago there was a colony of Glanville fritillary Melitaea cinxia, in Orpington, Kent, where an amateur breeder had some escapes, or deliberately let them go. This very rare butterfly only naturally occurs in the UK on the SW coast of the Isle of Wight and Purbeck, so it was very confusing for butterfly recording and monitoring. Releases of non-native animal species into the wild are technically illegal, since they may become invasive pests or spread disease.

Gardeners' World Web User 30/01/2009 at 10:44

Hi Richard,about two years ago I spent a sunny January day on my Manchester allotment. It was an unusually warm day but I shared it with a painted lady which was sunning itself on the privet hedge next to me. It clearly hadn't returned to Africa and had survived the winter!

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