Mining Bees

Mining Bees

Tawny mining bee (c) Nick Upton/ 2020Vision

Herefordshire Wildlife Trust's Conservation Senior Manager Andrew Nixon introduces some common mining bees to look out for in this blog.

Google ‘Mining Bees’ and no doubt a number of pest control companies come up.  Mining bees do seem to get some bad rep, but it is misplaced, they are an important pollinator and should be a welcome guest to gardens and the farmed landscape.

Mining bees are one of four main groups of solitary bees that also include the mason bees, carpenter bees and leafcutter bees. There are around 67 species of mining bee, making it the largest bee genus in Britain. They are called solitary bees because they do not form colonies in the way that honeybees or bumblebees do, instead the females independently build a nest and collect pollen for their young to feed on.  Despite being solitary in that sense, there might be many nests concentrated in a small area, giving the impression of social activity.

It is when this communal activity occurs in gardens (especially lawns!) that problems can occur.  They will excavate tunnels into the ground often leaving what’s described as ‘volcano’ shaped pile of soil at the tunnel entrance that some find unacceptable.  In actual fact this doesn’t harm the lawn at all, in fact it helps with aeration and drainage and these piles of soil soon disappear.  The bees will otherwise busy themselves with pollinating your garden flowers and crops and importantly they will not sting you or your pets. 

Small, neat circular hole in the earth with vegetation around

Mining bee nest (c) Karen Lloyd

Mining bees are quite variable in size depending on the species ranging from 5-17mm long. They are characterised by grooves running down the inside of their eyes (called facial fovea).  In the UK there are no other bees that have this characteristic. Like bumblebees, mining bees collect pollen on their hind legs.

Spring and early summer is a great time to look for mining bees as most emerge and are active during that time.  Only a few species emerge later, the ivy mining bee being one, which comes out at the end of summer/autumn to take advantage of the Ivy flowering season.  They can however be confusing so here are a couple of the more obvious and common species to familiarise yourself with.

Tawny mining bee (Andrena fulva)

Closeup of a bee on a leaf

Tawny mining bee (c) Nick Upton/ 2020Vision

This common species flies from March to June. The females of this species are the easiest to identify with a thick rusty red coat and about the size of a honeybee.  The males are smaller and brownish and play no part in nest building or providing for their offspring.   The females love to create nests in short turf and lawns and create the aforementioned volcano like spoil heaps.  In areas of light soil or a bare bank, you are likely to spot one.  They forage on early flowering shrubs and trees including willow, hawthorn and blackthorn as well as fruit trees.

As an aside this is one species that is frequently targeted by the Large bee-fly Bombylius majora, a parasitoid of Mining Bees and some solitary wasp species. This bumblebee mimic will often be seen hovering over an open nest cavity and flicks its eggs inside. Its offspring will then hatch in the nest and consume the pollen left by the adult Mining Bee, as well as the young bee larvae!

Ashy mining bee (Andrena cineraria)

Close-up of a bee on a yellow flower

Ashy mining bee (c) Chris Lawrence

This species typically flies from April to early August.  The females are the most distinctive and impressive looking having monochrome colouring - black with two ashy grey bands on their back. It is found on a range of habitats including heathland, open woodland, coastal grassland, quarries, gardens, parks, orchards and around cropped agricultural land.  It’s preferred food plants include, blackthorn and willow as well as fruit trees, although it can be found foraging on a wide range of species

Ashy Mining Bees are also known for nesting in lawns and create soil piles next to their tunnel entrances.  Interestingly, they also have a habit of closing their nest entrances one they have finished their days foraging, when it rains and if they are disturbed.  This also protects the nest from intruding parasites.

Early mining bee (Andrena haemorrhoa)

Close-up of a bee on a stick

Early mining bee (c) Chris Lawrence

This is another common spring bee species to look out for with females flying from March to July. Length varies from 8 to 11mm.  This female of this species has a striking blood red tip to the abdomen and a covering of foxy brown hairs on its back. The male is smaller and a lighter colour, often looking greyish.  Nesting sites include gardens, sports fields and road verges etc.  It likes early flowering species such as willow, blackthorn and hawthorn and loves dandelions.  It is also considered an important pollinator of fruit trees.

Hawthorn Mining Bee (Andrena chrysosceles)

This is a species that may require a little bit more hunting to find.  Although common across most of England it becomes more scarce in the South West and Wales and is much less common in gardens. The best time to see it is April to June.  It has a body length of 7 - 11mm and is darker looking than the species described above.  The females can look almost black with only a few buff coloured hairs on the thorax and head. The abdomen is shiny, with white bands of short hairs between the segments and orange hairs on the tip of the abdomen.

It likes visiting blackthorn and hawthorn flowers and will often reach its peak numbers when hawthorn and cow parsley are in flower.  It’s nests are not often encountered and the females typically nest alone rather than communally and it typically prefers woodland edges and hedgerows. 

 

If you're fairly confident of your identification skills, please do submit sightings to iRecord: https://www.brc.ac.uk/irecord/ to help build a clear national picture of our wildlife.