Wildlife Column with Prof Ian Rotherham
I have had quite a few enquiries this year about small ‘volcanoes’ of fine soil and sand appearing in gardens and the like.
These probably relate to hot dry periods we have experienced this summer and some are ant colonies and others are bees.
There are also distinctive solitary wasps that dig small burrows.
Peter Wolstenholme sent me a picture of a very neat little pile of earth photographed by the side of a dry footpath in Woodhouse, Sheffield. Peter’s picture is almost certainly the nest-hole of a ‘solitary mining bee’.
There are about 250 species of solitary bee in the UK and these include the mining bees which tend to favour dry, crumbly substrates, such as sandy soils, for their nests.
These insects lay a single egg in a cell which is provisioned for the youngster, and then sealed. Some of the species may have several cells in a single nest and the nests may be colonial along sandy riverbanks such as at the River Derwent at Chatsworth or above the gritstone edges of the Peak District.
These are mostly ‘Andrena’ mining bees, but there are also leaf-cutter bees, and mason bees.
The leaf-cutter bees do get a lot of attention when they cut neat holes in bushes such as prize roses in gardens.
Even more amazing is when they fly through the air carrying the neatly-cut pieces of leaf which they use to form a nest.
These really do look like pieces of flying leaf as they speed through the air!
The adult bees like to make the leaf-nest within a hole of some sort and I have had then in the middle of a patio table where the pole fits, and even in the keyhole of a patio French window door.
The effect of them flying in with their pieces of cut leaf was really rather odd.
All these bees are important as pollinators now that honeybees are in decline.
However, they do tend to be quite specialised in their choice of plants from which to gather pollen; less so for nectar.
Professor Ian D. Rotherham, of Sheffield Hallam University, researcher, writer and broadcaster on wildlife and environmental issues.