There are approximately 280 species of bees in Britain, with about half of these found in London. Up to 100 species occur in Tower Hamlets.
Only one of these, the Honey Bee (Apis mellifera), is kept in hives by people to produce honey. It is effectively a domestic animal, not a wild animal. Honey bees are social insects, living in very large colonies of thousands of individuals.
The other species are collectively known as wild bees, and are not kept by people. They include the bumblebees (24 British species), which are the large, fat, furry bees that correspond to most people’s image of a bee. Bumblebees are social, with colonies of a few dozen or a few hundred individuals. The rest of the species are solitary bees, many of them very small. Several nationally rare wild bees occur in Tower Hamlets, including the Brown-banded Carder Bee (Bombus humilis), Black Mining Bee (Andrena pilipes), Red-girdled Mining Bee (Andrena labiata) and Clover Blunt-horn Bee (Melitta leporina). See this PDF for more information on these scarce bees.
Importance of bees
All bees are important pollinators of crops and wild plants (as are other insects such as butterflies, moths, flies and beetles). It has been estimated that without pollinating insects, the cost of hand-pollinating food crops in Britain would be over £1 billion per year. Honey bees, due to their large numbers, are one of the most important pollinators of food crops. But they have relatively short tongues, so are not able to pollinate some crops, which can only be pollinated by bumblebees. Honey bees have an additional economic importance in the production of honey.
Threats to bees
There has been much in the news in recent years about declines in bees, and a lot of confusion between the threats to Honey Bees and wild bees. Both face threats, but these are different in nature.
The main threats to Honey Bees are from diseases, such as the deadly Varroa mite, which are largely spread by poor beekeeping practices. Pesticides are also a threat. However, despite these threats, Honey Bees are not declining. In London as a whole, and in Tower Hamlets, there are more honey bees now than there have ever been, as urban beekeeping becomes more popular. In urban areas, finding enough food – nectar and pollen from flowers – is likely to be a problem for Honey Bees.
The main threats to wild bees are pesticides and loss of habitat – mostly flower-rich meadows, but brownfield sites are also very important in urban areas. Neonicotinoids, a type of insecticide widely used in agriculture, are particularly harmful to bees and other pollinators. Most species of wild bees are declining, and several species are threatened with extinction. In urban areas, competition with Honey Bees for the limited available nectar could be a further problem for wild bees.
When people hear about the decline of bees, the knee-jerk reaction is to encourage more bee hives. This will potentially increase the number of Honey Bees (if there is sufficient food to support them), but will certainly not benefit wild bees, and might be detrimental to wild bee populations through extra competition for limited nectar and pollen. As discussed above, it is wild bees, not honey bees, which are in decline. If people want to keep bees because they have a genuine interest in doing so, and/or want to produce honey, that is fine. But for anyone who simply wants to alleviate the threats facing wild bees, there are much more appropriate ways to help.
The best way to help bees is to plant lots of nectar-rich plants. This can be by creating wild flower meadows, or through ornamental planting. Plants should be chosen to ensure flowers for as much of the year as possible. This will benefit both Honey Bees and wild bees. Many of the solitary bees do not require huge areas of habitat to support sustainable populations and even small interventions in individual back gardens, street planters and window boxes can make a difference.Most bees will visit a wide range of flowers, but some only feed on just one or a few species of flowers. For example, the Harebell Carpenter Bee (Chelostoma campanularum – photo left) will only feed on bellflowers. The Clover Blunt-horn bee will feed on nectar from a wide variety of flowers, but females collect pollen only from legumes, mainly White Clover. Local bee expert Mark Patterson of Api:Cultural has produced a list of the best garden plants for bees, and a matrix showing the flowering times and colours of good bee plants, including plants which benefit bees that feed from a narrow range of flowers. Further lists of nectar plants are available on the Royal Horticultural Society and London Beekeepers Association websites. Many solitary bees, such as the scarce Fork-tailed Flower Bee (Anthophora furcata – photo left), excavate nest burrows in soft decaying dead wood, typically in rotting tree stumps. Others use existing cavities in deadwood left behind by beetles. Species reliant upon pre-existing cavities in dead wood can be attracted to nest using artificial nest boxes made from blocks of timber with holes drilled into the wood, or boxes filled with hollow bamboo or wood tubes. Species which excavate their own cavity will not use nest boxes, but can be helped by providing piles of logs and other dead wood. Standing dead wood, such as tree stumps left above ground, is particularly valuable.
While Honey Bees will travel several kilometres from their hive to find nectar and pollen, many solitary bees will only travel much shorter distances. The Harebell Carpenter Bee, for example, will not forage more than about 15 metres from its nest. For bee boxes and dead wood habitats to be valuable to these species, they need to be placed in close proximity to good nectar sources.
Beekeepers can also help wild bees by not overstocking hives, and by following good husbandry practice to ensure Honey Bee diseases are not spread to wild bees. They can also keep a look out for the invasive Asian Hornet (Vespa velutina) which is an apex insect predator and feeds on a wide range of bees and other beneficial insects. Honey Bee apiaries are used as an early detection network for the identification of incursions of this invasive species.
Bees and the Local Biodiversity Action Plan
Wild bees are a priority species group in the Tower Hamlets Local Biodiversity Action Plan, which includes a target for planting more nectar-rich flowers, which will also benefit Honey Bees. It also includes targets for providing suitable nest sites for wild bees, such as bee boxes, bug hotels, and dead wood.
Header photo: Brown-banded Carder Bee by John Archer
Click photos to enlarge