The UK is home to 24 species of bumble bee all with differing colours, sizes, habitat and behaviours. Bumble bees are also social insects living in colonies of up to 200 workers, one queen, and drones in autumn. The most common species found in the UK include the buff-tailed (pictured on right), red tailed and early bumble bees. A full list of the UK's bumble bees can be found here. Bumble bees are effective pollinators of foods that make our diets interesting, such as strawberries and tomatoes. They are often used in commerical green houses for this purpose. Bumble bees are excellent pollinators owing the to the range of tongue lengths throughout the bumble bee family allowing them to reach nectar on the flowers of many plant species.
Honey bees are excellent pollinators and widely abdundant around the UK owing to the popularity of beekeeping. Honey bees are essential to the effective pollination of many crops worldwide. In the USA thousands of colonies are shipped across the country each year to facilitate the pollination of crops such as almonds and melons. In addition to crop pollination honeybees also provide crucial pollintion of many non-crop plant species, maintaining genetic diversity in plants worldwide. Honey bees are social insects that live in colonies of up to 80,000 workers, with one queen and up to a few hundred drones.
There are around 225 solitary bee species in the UK. They range in colours, some wonderfully coloured like Andrena cineraria, sizes, some as small as 25 mm, habitats, and behaviour, including mimics/kleptoparasites such as Nomada goodeniana. As the name suggests these bees are predominantly solitary with females storing nectar and pollen in a brood chamber, however some species such as Lasioglossum Malachurum do live in social groups made up of workers and a primary reproductive female. Though not as productive or effective as honeybees and bumble bees at pollination, they are still vitally important and an extremely diverse pollinator group. An excellent visual guide to solitary bees by Steven Falk can be found here.
Fly pollinators can be generally grouped into two categories, hoverflies, the well known pollinators of many flowers, and all other flies, the forgotten pollinators. Hoverflies are generally accepted as good pollinators, however in a recent paper they found that there was no significant difference in pollen load between the two fly groups. As pollinators flies differ vastly to bees owing to their differing mouth parts, behaviour and phenology.
Key UK pollinators
Butterflies and Moths
There are 59 butterfly species which breed in the UK. Many of which are characteristic of the British summer, such as the red admiral (Vanessa atalanta) or peacock (Inachis io) butterfly. Butterflies and moths are not as effective in pollination as bees and flies owing to their slender appendages, with the exception of Hawk and hummingbird moths, but are still important species within pollinator networks and provide a vital ecosystem service. They are, unfortunately, in population decline due to their susceptible to habitat loss. An interesting report into the state of the UK's butterflies can be found here.
The order of beetles in the UK is large and diverse, with species wide ranging in colours, habitats, shapes, behaviours, phenology and forage. A large proportion of beetles are carnivores and detritivores, however there are also many which solely or opportunistally forage on flowers for pollen and nectar. Some species such as the Pollen beetle Meligethes aeneus spend the entirety of their life cycle in or around flowers, especially oilseed rape where it is a particular pest species. Other species are less damaging such as the flower beetle Oedemera nobilis which feed on pollen, indirectly provide effective pollination of many plants.
Honey bee (Apis mellifera)
Early morning bee (Andrena Haemorrhoa)
Buff tailed bumble bee (Bombus terrestris)
Bee fly sp. (Bombyliidae)
Flower Beetle (Oedemera nobilis)
Peacock butterfly (Inachis io)
The UK is host to a variety of pollinators including bees, hoverflies and butterflies. Outside these three main pollinator groups there are a plethora of effective pollinator species, including many other flies and beetles! This was recently discussed in a paper out of Jane Memmott's group, The forgotten flies: the importance of non-syrphid Diptera as pollinators.