Bee hotels need good management, just like any other establishment, says Kate Bradbury
Summer is packed away in my shed. Four cleaned and sanded bee hotels, plus a box of beautiful solitary bee cocoons. I check on them regularly, making sure no spiders have got in to the boxes, that mould hasn’t started to form on the cocoons or that I’ve missed any parasites lurking in wait for the bees to emerge in spring.
I do this every autumn. Studies have shown that “managing” bee hotels helps prevent a build-up of parasites and fungal infections. Bee hotels are artificial habitats after all – if we clean out bird boxes we should apply the same principle to bee hotels, ensuring wild solitary bees nest in as-new conditions each year. To those thinking “but nature doesn’t clean out bird boxes”, consider this: nests in tree holes break down and are absorbed by the tree, with some studies suggesting they feed the tree in the process. Like bee hotels, bird boxes simply don’t exist in the wild.
Red mason and leafcutter bees – which most commonly use bee hotels – are cavity nesters. They typically nest in hollow plant stems or holes in dead wood made by beetles. The female makes a cell of mud or leaves, gathers pollen and lays an egg on it, sealing it up with more mud or leaves before starting the next cell. The egg hatches into a grub, which eats the pollen and then metamorphoses into an adult bee that hatches out of its cocoon exactly a year after it was laid. Magic!
I’ve heard that one of the best things to grow for red mason bees is hogweed (Heracleum sphondylium) – simply sow and let nature take its course. As the stems decay their hollow centres are exposed, which bees will nest in. A year later, when the stems have been further