It is Pollinator Awareness Week this week so I thought I would do a blog post on bee genera to show you quite how diverse and wonderful they are. Bees are by no means the only pollinators in Britain but are my favourite so are a lovely place to start, hopefully I will blog throughout the week. I am no expert in British bees but do love them. There are 250 species of bee in Britain, every one is unique and fascinating. Unfortunately I haven’t seen or photographed bees in some of the smaller genera so I can’t show you how awesome they are.
In Britain there are around 65 species of bee in the genus Andrena, making it the largest bee genus in Britain. These bees are quite variable in size and form but all nest in the soil. These bees have short pointed tongues and are characterised by the grooves (facial fovea) running down the inside of their eyes which is almost unique in Britain to this genus. Pollen in collected on the hind legs.
There is only one bee in this genus in Britain, Anthidium manicatum , the wool carder bee. This attractive bee collects the hairs from plants to build its nest and is unusual as the females of this species emerge before the males. The males are very territorial and defend a patch of flowers for its female to forage from, often killing other insects which try to visit these flowers. Pollen is collected by females on the underside of the abdomen.
This genus comprises of 5 species in Britain, they all look fairy chunky like bumblebees (for which they are often mistaken) and are incredibly cute. Four out of the five species nest in soil with A. furcata nesting in wood, including dead wood in my garden. These bees have long tongues to reach into deep flowers and pollen is collected on the hind tibia back to nests which are often densely packed in the best nest sites.
There is only one bee species in this genus in Britain, the Honey Bee (Apis mellifera), which nests socially.
These are the bumblebees and are often the bees that people think of when they think of bees. There are 25 species in Britain including cuckoo bumblebees and are certainly brighten up my garden with their familiar buzzes. Bumblebees are social and in general have three casts – workers, queens and males. Cuckoo bumblebees however no not have workers as they get their hosts workers to work for them and provision for young of a different species! Female bees (workers and queens) collect pollen on pollen baskets on their hind legs to provision a nest. Males do not collect pollen and neither do cuckoo bee species.
In Britain there is only species in this genus, Ceratina cyanea . This is a small blueish carpenter bee which nests in the pithy stems of plants like bramble. Interestingly this bee overwinters so adults can be found at any time of year. This species is only found in a small area of Britain and is certainly on my ‘must see’ list.
These bees are wonderful and are quite specific to their host plants. There are only 2 species in Britain, C. campanularum and C. florisomne. C. campanularum likes to visit flowers of the family Campanulaceae and collects a large proportion of its pollen from the plants. C. florisomne seems totally dependent upon buttercup flowers. These are aerial nesters often nesting in thatch and are so small that they are best found by checking appropriate flowers. Pollen is collected on hairs underneath the abdomen (the scopa).
There are 6 species of these leafcutter bee (Megachile sp.) cuckoos found in Britain, all are quite striking. The female has a very point abdomen which she uses to cut through the leaves of the hosts nest and lay her egg in there. Species in this genus are hard to separate.
This genus contains a number of very similar looking species which often favour a narrow group of plant species. For example C. fodiens visits certain Asteraceae and C. succinctus visits heather. C. hederae only collects pollen from ivy flowers and is a species that has colonised Britain in recent years but is rapidly spreading northwards.
The one species in this genus, Dasypoda hirtipes. The females of this species are one of the most beautiful and distinctive bees in Britain due to their yellow ‘legwarmers’ on the back legs, used to collect vast amounts of pollen. These hairs are also used to rake out soil when nesting, creating distinctive fan shaped spoil heaps. Sadly this is a rather rare species of sandy soils so I have never seen it.
There are only two species found in this genus in Britain, Epeolus variegatus and E. cruciger. These are cuckoos of bees in the genus Colletes. These two species do not need to collect pollen as they take over the nests of Colletes bees, but do drink nectar from a variety of plants.
There is thought to be one species in this Genus left in Britain, Eucera longicornis . This species is top of my list of species to see in Britain as it is extraordinary, with the males having amazingly long antennae. Sadly this soil nesting bee has declined in numbers and distribution dramatically, although it is still common in some coastal areas in south-western Britain. It is also present on the Gatwick Airport site, found by the marvelous Rachel Bicker.
There are 7 species in this genus in Britain and are all similar in appearance to Lasioglossum species. These bees have short pointed tongues and often nest in soils, collecting pollen on the underside of the abdomen and on the legs. These species can be solitary or primitively eusocial in behaviour and are often used for behavioral studies.
Another genus with only two species in Britain, H. rubicola and H. truncorum. Little is known about these species but H. truncorum seems to be spreading at least and seems associated with heathlands. Pollen is collected on the scopal hairs on the underside of the abdomen.
There is only one species in this genus in Britain, Hoplitis claviventris. This widely distributed but rare species nests in stems and looks rather similar to Osmia species.
The genus Hylaeus contains 11 species in the British Isles, all of which are aerial nesters. These bees are often called yellow-faced bees as they usually are black with patches of yellow on their faces. This group doesn’t have any pollen collecting aparatus so collect pollen and nectar in their mouths before regurgitating it back at the nest.
There are 33 species in this genus in Britain. All of which look similar to Halictus species. These bees have short pointed tongues and often nest in soils, collecting pollen on the underside of the abdomen and on the legs. These species can be solitary or primitively eusocial in behaviour and are often used for behavioral studies.
Another genus for which we only have one species in Britain, Macropis europaea. This species is unique in this country for having females which provision their nests with fatty floral oils which is collected on pads on her feet. The main foraging plant for this species is yellow loosestrife so I can never go past a patch of this plant now without checking it for bees, despite the fact that this species hasn’t been seen in this area before.
These are the leafcutter bees, building their nests out of sections of leaves cut from plants. There are 7 species in Britain, all of which look rather robust and even the males have sharp jaws. Pollen is collected by females on the scopal hairs on the underside of the abdomen. Up to 40 pieces of leaf are needed just to build one nesting cell for one offspring, rather remarkable indeed.
This is another genus in which there used to be two species in Britain, but now only one is found. Melecta albifrons is a black and white cuckoo bee of the hairy footed flower bee Anthophora plumipes. This species is generally quite rare and is best at the nest sites of its host where it can be locally common. As this bee is parastitic, it doesn’t collect pollen.
This genus only has 4 species in Britain. All these species have a narrow range of plants in which they visit and are superficially very similar to Andrena species, they have more knobbly antennae though. Pollen is collected on hind legs.
There are 33 species in this genus in Britain, with 5 of these restricted to the channel islands. These wasp-like bees are all parasitic on other bee species, with the Nomadas being quite host specific. These bees can often be found collecting nectar from flowers and flying low to the ground around the nest sites of their hosts.
This has to be my favourite bee genus in Britain due to the range of attractive bees in this genus, all of which have fascinating life histories. There are 11 species in this genus, all of which collect pollen on the underside of their abdomens. Their life histories vary dramatically though with some species nesting in snail shells and others nesting aerially in stems. This group contains the familiar red mason bee, Osmia bicornis , which pollinates fruit crops far more effectively than honey bees. Some of these species are generalists, collecting pollen from a variety of plant species, while others are very specific.
This genus comprises of two bee species in Britain, P. banksianus and P. calcaratus. These bees look like skinny black Andrenas but their wing veination is different. They carry pollen on their hind legs and are generally quite rare (I have never seen one).
There are 16 species of these often black and red cuckoo bees in Britain. They have lost most of their hairs as are parasitic on other species so don’t need to collect pollen. These are lovely little bees, often seen flying around nest sites, I just wish they were easier to identify!
There are 4 species in this genus in Britain. These bees are small, black and hairless as they are parasites on other bee species so have no need to collect pollen. These bees are all rather rare.
Pollinators have never been so important and to protect them, we need to appreciate them and record them. In the case of bees, there is no better place to look for info in Britain than the Bees, Wasps and Ants Recording Society’s website. Do put any records that you have on iRecord too as they can then go onto the database, if verified and make a difference to conservation.