Wales Biodiversity Partnership

Bumblebees

Bumblebees are endearing and familiar insects. Their animated behaviour and deep buzz as they fly from flower to flower makes them a delight to watch.
Sadly though, our bumblebees have been declining because of changes in agricultural practises that have largely removed flowers from the landscape, leaving the bumblebees with little to feed upon. Most UK species have declined greatly in recent years, and two have become extinct in the UK since 1940.
Bumblebees belong to the order ‘Hymenoptera’ which includes Bees, Wasps, Ants, Sawflies. There are distinct differences between the appearance and lives of bumblebees, honeybees and solitary bees. Bumblebees are larger and hairier than honeybees and solitary bees, which makes them perfectly suited for colder climates. Bumblebee nests are small and they do not store large quantities of honey, so they are more sensitive to the availability of pollen and nectar-rich flowers to feed on. Bumblebees do not swarm and are not aggressive. Only female bumblebees can sting and they will only do so if they feel very threatened.
Bumblebees play a vitally important role which we shouldn’t take for granted. On top of pollinating a wide range of wild plants across the landscape, they also pollinate the crops that provide us with food to eat. Without their pollination service, many wildflowers could disappear. Key ingredients from our diets, such as beans, peas, raspberries and tomatoes would be harder to produce and much more expensive without British bumblebees

Where do bumblebees occur?
There are around 250 species of bumblebee in the world, and most of these are found in the northern hemisphere, although South America has a few native species, and New Zealand has some which were introduced from Britain.
Two species of bumblebee have become nationally extinct in the last 100 years. In the same period, a new species, the Tree bumblebee, colonised the UK from Europe. The UK therefore has 24 resident bumblebee species, and BBCT are working on a project to reintroduce one of the extinct species, the Short-haired bumblebee.
Only eight species are commonly found in most places. Bumblebees are found in a variety of habitats and most people should be able to attract them to their gardens if they have the right kinds of flowering plants.
Some species are less common and are only found in a few locations. For example, the Shrill carder bee, which is now only found in seven areas in southern England and Wales. This species previously had a wide distribution throughout the south of the UK, but habitat degradation has seen its numbers decline dramatically in most places.

Conservation Projects in Wales

The Bumblebee Conservation Trust and many other organisations in Wales and across the UK are working hard to try to increase habitat for bumblebees. A particular focus of the Bumblebee Conservation Trust is to restore and increase the number of flower-rich grasslands in areas where there are rare bumblebees such as the Shrill carder bee.

The hugely successful Bees for Everyone project which started in 2011 and finished in December 2014, was funded by the Heritage Lottery Fund, and also funded by Natural Resources Wales. ‘Bees for Everyone’ aimed to deliver more flower-rich habitat for rare bees, as well as raising awareness of the importance of bumblebees and what people can do to help. In Wales, our Conservation Officer has worked on delivering habitat on over 40 sites across south Wales, with over 1,700 Hectares of habitat being delivered. This project has involved working with a variety of partners and landowners across Wales.

Gardening for bumblebees
British gardens cover more than 1 million acres and can be a lifeline for bumblebees. No matter how small your garden, you can help by providing lots of bee-friendly flowers throughout the year. By bee-friendly we mean flowers that are rich in pollen and nectar. Many ornamental plants that are commonly found in British gardens, such as pansies and begonias, are of no value to wildlife. Years of cultivation for showy blooms mean that these colourful flowers often produce little pollen or nectar. There are hundreds of beautiful flowers that do offer these rewards though, including foxgloves, lavender, geraniums, herbs and wild roses that you can add to your collection.

About the Bumblebee Conservation Trust
The Bumblebee Conservation Trust was established because of serious concerns about the 'plight of the bumblebee'. In the last 80 years bumblebee populations have crashed and several species are threatened with national extinction. Bumblebees are an important and cherished component of our biodiversity.  The Bumblebee Conservation Trust aims to ensure that populations of these species have a long-term future in the UK.


Bumblebees in Wales

There are currently 22 species of bumblebee found in Wales. Two species, Bombus subterraneus and B. distinguendus are now extinct from Wales. Wales is an important place for rare species, particularly in the south of the country. These include 5 ‘UKBAP’ and Wales ‘Section 7’ priority species – Shrill carder bee (Bombus sylvarum), Brown-banded carder bee (Bombus humilis), Moss carder bee (Bombus muscorum), Red-shanked carder bee (Bombus ruderarius), and Ruderal bumblebee (Bombus ruderatus). In addition, the scarce Blaeberry bumblebee (Bombus monticola) occurs across much of the Welsh uplands where there is sufficient flower-rich habitat. The scarce Broken belted bumblebee (B.soroeensis) is also occasionally recorded. However, some species are increasing, notably the cuckoo species Bombus rupestris and the new arrival Bombus hypnorum (Tree bumblebee).

Shrill carder bee
The Shrill carder bee, Bombus sylvarum, is probably the UK’s rarest species of bumblebee.
In the 1900s, the Shrill carder bee was seen throughout most of England and Wales. Since then, the populations have declined quickly, and nowadays we only have about 7 separate populations left. These remaining populations are mostly in south Wales and England, where it still thrives on meadows and flower-rich grassland. Having such isolated populations is not ideal because it can cause inbreeding amongst closely related bees, so we are working with landowners to try to create more habitat that will protect existing populations and link them up.
Shrill carder bee M ClarkShrill carder bee 2 BBCT
Shrill carder bee ©Mike Clark Shrill carder bee ©BBCT

Shrill carder bee distribution

Maps showing the UK distribution of the Shrill carder bee. Maps courtesy of Bees Wasps & Ants Recording Society (BWARS)

Bumblebee Life Cycle

Bumblebees are social insects and live in nests of up to 400 individuals. Each nest is ruled by a queen
and lasts for just one year. This is different to honeybee hives which remain active for several years.
-In early spring the queen emerges from hibernation to start a new nest (1)
-Her first task is to build up her energy reserves so it is really important that she can find plenty of pollen and nectar- rich flowers (2)
-Once she has found a suitable nest site she will rear her first batch of eggs – a group of female workers whose job it will be to feed and nurture the colony (3).
-This process is repeated throughout the summer with the queen rarely leaving the nest. Bumblebees rarely nest in the same location two-years running (4).
-Towards the end of the summer the queen produces male offspring, along with new queens (5).
-After mating the males die off, as do the old queens and workers. Only the new, fertilised queens survive to hibernate through the winter and establish their own nests the following year (1).
Bumblebees rarely nest in the same location two-years running.
Bumblebee life cycle

Image and text courtesy of BBCT