This month, hopefully you will see at least one new bumblebee species, a new mason bee, four types of mining bee, the now familiar Hairy-footed flower bee, and two ‘cuckoo’ bees – the Mourning bee and the Vestal cuckoo bee. (All photos credit: Penny Metal)

You will continue to see some of the bumblebees you first spotted in March and April, but instead of queens you will now probably be seeing the smaller worker bees foraging on flowering trees and plants.  

How to ID May bumblebees:

• Tree bumblebees (Bombus hypnorum) with their ginger thorax, black body and white tail could be the new occupants of your blue tit box if the chicks have fledged. Be prepared for noisy buzzing outside their new home as gangs of males compete to mate with virgin queens. (As you can see from the photo, the male on top is much smaller than the queen.) Tree bumblebee colonies vacant a bird box at the end of the summer, so it will be empty for the blue tit family next spring. I still find it hard to tell Common carder bees (Bombus pascuorum) and Tree bumblebees apart when they are flying, despite the latter having a darker body and a white tail.

Top ID tip to tell a Common carder bee from a Tree bumblebee – both sport a bright ginger pile at this time of year (later in the year, the former fades and the later goes a bit bald), so the best way to tell them apart now is to focus on getting a look at their bottom. The Tree bumblebee has a tiny white bottom and a darker body (abdomen). The Common carder bee is brown all over. Good luck!

Bumblebee cuckoo bee

•  Vestal cuckoo bee (Bombus vestalis) – also known as Southern cuckoo bee because she used to be more common in the south of England – looks very similar to a Buff-tailed bumblebee (Bombus terrestris). That’s because it resembles the bee whose nest it takes over. Like the cuckoo bird (hence the name), it lays its eggs in the nest made by the host. But the cuckoo bee will actually kill the host queen and her eggs and dupe the worker bees into raising her young. Cuckoo bees are either male of fertile females. They do not have queens or worker bees..
• There are six cuckoo bumblebees in the UK. Because Buff-tailed bumblebees are so common, so too is the Vestal cuckoo bee. Their presence means the host population is healthy.

Top tip for telling a Vestal cuckoo bee from a Buff-tailed bumblebee – The easiest way to tell these two large bumblebees apart is that the cuckoo has a longer white tail and above the tail is a pale yellow band. It’s a paler yellow than the dirty gold on the bee’s thorax and paler than the Buff-tailed bumblebee’s golden bands. The Vestal cuckoo female is a similar size to a Buff-tailed bumblebee queen but much bigger than Buff-tailed workers. Its wing may seem a bit darker and it never carries pollen (as the host workers will feed its young). This is true for all cuckoo bumblebees.

How to help bumblebees in May:

1. Leave a patch of the garden wild for nesting sites and don’t disturb a nesting site if you find one for example in a compost bin or under a garden shed (it will only last until the end of the summer). Leave some permanent long grass in which Common carder bees may nest.
2. It’s not too late to put up a blue tit box for the tree bumblebee to nest in. Again, they will leave at the end of the summer and birds can use it next spring.
3. Buy and plant alliums, catmint and cotoneaster from garden centres to provide food this month for short-tongued bumblebees. Foxgloves, honeysuckles and thistles for the long tongued bumblebees.
4. It’s not too late to grow from seed annuals that provide late summer bee forage such as sunflowers, cosmos and Anise hyssop.
5. Don’t mow the lawn (let clovers and dandelions flower). See the Plantlife No Mow May campaign.
6. Ditch the weed killers and pesticides.
7. Scatter wildflower seeds or seed balls in pots or on bare earth. The annuals will flower later in the summer and perennials next year.

How to ID May solitary bees:

• Grey-patched mining bee (Andrena nitida) is one of the commonest mining bees in southern Britain, extending up to Lancashire and Yorkshire. She has a brighter red, fluffy pile on her thorax than the short-fringed mining bee, and grey patches on her black abdomen. They can be found foraging on spring blossoming shrubs and trees and dandelions and in scattered nests in flat or sloping turf and lawns.

Top tip for finding a Grey-patched mining bee – find it’s more striking waspish-looking Nomad bee, (another name for a cuckoo), Flavous nomad bee (Nomada flava).  You can see them on the ground searching out a Grey-patched mining bees’ nest to take over, and then you may spot the host bee herself.

• The short-fringed mining bee (Andrena dorsata) is widespread in southern England. Sporting a reddish-brown fluffy pile on her thorax, a smooth black body with thin stripes, and a hairy dorsal fringe on the top of her back leg, the female should hopefully be easier to identify on dandelions and daisies than some of the other small, brown mining bees also around at this time of year.

• Hairy-footed flower bees (Anthophora plumipes) have been flying for a couple of months now so you are probably becoming accustomed to seeing them darting noisily around patches of comfrey and wallflowers with their tongues outstretched. Many of the black females will have mated and are now busy collecting pollen on their hairy hind legs for their young.
• Ashy mining bees (Andrena cineraria) A distinctive black and grey stripped bee (around 11-14mm), which nests in bare ground, footpaths and tracks. Although solitary, they nest next door to each other in dense aggregations, so hundreds can emerge at the same time. But don’t worry, solitary bees don’t sting and are short-lived (around 2 months)!
• The Mourning bee (Melecta albifrons) is another black and grey bee. Her coat is a fluffy grey/black colour, edged with lateral white spots. Despite her cute appearance, these are the Hairy-footed flower bees’ cuckoo. The female lays her eggs in the already made nest and when her larvae hatch they steal the pollen collected by the Hairy-footed flower bee for her own babies.  A quarter of the 20,000 plus bee species on the planet are cuckoos.

Top tip for telling a Mourning bee from an Ashy mining bee – the former is rounder and fluffier, like its host bee, and also has lateral whitish spots down its body. The Ashy mining bee has a longer, smoother black body and is often found near to the ground.

• Common mini-miner (Andrena minutula). If you see a tiny mining bee (4-5mm) at this time of year, chances are it will be this mini-miner bee because as its name suggests it’s the most common of the 10 species of mini-miners in the UK. They have a hairy fringe along the thorax and markings on their head if you can get that close. They are most visible on dandelion type flowers and sallow (willows). They nest in loose soil in large groups.
• Blue mason bee (Osmia caerulescens) – bit smaller than the more common Red mason bees, the males, which are flying now, have a fluffy brown pile of hair over a dark metallic-coloured body. The females look blueish-black with a box-shaped head. They will nest in manmade bee hotels, but construct the cells and plug the tubes with chewed pieces of leaf. You may see them on a variety of flowers in an urban garden. The females come out a week or so after the males and they are around until July.

How to help solitary bees in May:

1. Plant wallflowers and comfrey for long-tongued Hairy-footed flower bees. Flowering fruit trees, willows, spurges, alkanet and forget-me-nots for red mason bees, and mining bees.
2. For more plants, shrubs and trees that are good for different types of bees, see our Plants for Bees and Trees for Bees guides and blog about Shrubs for Bees.
3. Leave old mortar untouched as Hairy-footed flower bees and Red mason bees may be nesting here.
4. It’s not too late to make cob bricks with holes in that Hairy-footed flower bees may nest in. See how to make them with clay soil, builders’ sand, straw and water in this wonderful video by ecologist John Walters.
5. It’s not too late to install bee hotels in a warm location at least a metre off the ground, where Red mason bees can check-in and lay their eggs. We like to use these flat-pack bee hotels we have made, filled with either cardboard tubes or bamboo tubes that are 150mm long and around 5mm in diameter.
6. Leave a patch of bare earth for mining bees to burrow and where Red mason bees can collect soil to make partition walls between birthing chambers and to plug their nests.
7. Don’t mow the lawn to let dandelions and clovers grow. Small, brown mining bees are easiest to see on bright yellow dandelions. I now let dandelions grow in my herbaceous perennial flower borders to spot these bees.
8. Ditch the weed killers and pesticides.