Solitary bees

Out of these 250 species ... over 90% of them are solitary bees. There are too many to name and talk about each one individually ... so I have picked but a few.

By solitary we mean that a single female, after she emerges from her pupae and is mated by a male, constructs, provisions and lays an egg in each cell in a nest by herself. This in comparison with social (called eusocial) bees like the Bumble Bees, Honey Bees and Stingless Bees, all of whom have a Queen who lays eggs and a number of workers who look after them.

Female solitary bees prepare their own nest in the ground, in cracks or crevices in walls, or in wood. They gather nectar and pollen as food for their own offspring, and provide little or no further care after their eggs are laid.

Solitary bees come in many different sizes, colours and shapes. Common solitary bees are mason bees, miner bees, sweat bees, wool-carding bees and carpenter bees. They vary in colour from basic black to bright metallic green, blue or red. Some solitary bees superficially resemble wasps.

Leafcutter bees ... nest in soft, rotted wood, thick-stemmed pithy plants such as roses and in similar materials that the bees can easily cut through and excavate. Nest tunnels may extend several inches deep and coarse sawdust is thrown out at the entrance. Leafcutter bee cells

After the nest has been produced, leafcutter bees collect fragments of leaves to construct individual nest cells. The bees cut leaves in a very distinctive manner, making a smooth semicircular cut about 3/4-in in diameter from the edge of leaves.

These are carried back to the nest and used to fashion nest cells within the previously constructed tunnels. Each leaf-lined cell is then provisioned with a mixture of nectar and pollen. An egg is then laid and the cell sealed, producing a finished nest cell that somewhat resembles a cigar butt.

Leaf-cutter bee entering its nest with part of a leaf

Photo by: Terry Stanfield Sutton Coldfield West Midlands August 2007

A series of closely packed cells are produced in sequence so that a finished nest tunnel may contain a dozen or more cells forming a tube 10cm to 20cm long. The young bees develop and remain within the cells, emerging the next season.

Leaf-cutter bees differ from related species in that they collect pollen on their abdomens rather than on their hind legs.

Masonry bees ... much like leafcutter bees, prefer south-facing nest sites, and use naturally-occurring holes in either the bricks themselves or in the mortar joints (especially soft mortar, with a high lime or sand content).

Nests are established in spring or summer and contain six to 12 eggs, each in a cell provisioned with pollen and nectar and sealed, usually with mud. New adults emerge the following year to repeat the cycle

Miner bees ... are one of many familiar black and yellow summertime bees often mistaken for bumble bees. These are also solitary bees and do Miner bee Andrena sp.

not collect honey nor do they sting, though they could bite if handled roughly. They are good pollinators and serve an increasingly important role as honey bee populations decline. You can actually enhance miner bee populations by providing dried mud blocks for nesting.

Large carpenter bee - Xylocopini virginica

Carpenter bees ... the most common species are in the genus Xylocopa, which resemble bumble bees, except that these carpenter bees have a relatively smooth abdomen and bumble bees have very hairy abdomens. Carpenter bees dig holes in dead wood where they lay eggs and provision them with nectar and pollen. Carpenter bees are sometimes considered pests because they will bore holes in wooden sheds, porches, and other structures, but rarely do any serious damage. Small carpenter bee - Xylocopa Ceratina

Common carpenter bees are about 25mm long, but some species are smaller and have black or metallic coloration, like the Ceratina sp. pictured right.

Once again like the leaf cutter and mason bee, adults spend the winter in nests constructed the previous year, and become active in April or May. After mating, females construct new nesting tunnels or use pre-existing tunnels. Nesting tunnels are about 12mm wide and start on the end of wooden beams or at right angles to a surface for 10mm to 25mm before turning and following the wood grain. Tunnels are clean cut and may extend 15cm to 20cm. Females collect pollen and nectar to produce a dough-like mass called "bee bread." The eggs hatch into larvae that feed on the bee bread in their cells.

Ever heard of the"The Spring (Hairy-footed) Flower Bee" ... Anthophora plumipes Try looking it up on your search engine ...

There are 19 different species of bumblebee found in the UK and three of these species are already extinct with a further nine are on the critically endangered list.

"Bumblebees are disappearing at such an alarming rate in Britain that scientists are warning they could be wiped out within a few years.

Their numbers have been falling in recent years, largely due to intensive farming practices. "The last 50 years have seen hedgerows ripped up and most of the flower-rich grasslands once used for grazing have been reseeded with rye grass

Bumblebees are most efficient pollinators. They grab the anthers of flowers and shake them to free the pollen of some blossoms. Bumblebees will work on cool, overcast days while honeybees remain in their hives.

Cuckoo bees do not build their own nests. Like the cuckoo birds that get another species to raise their young, these bees lay their eggs in other bees' nests.

The females cuckoo bee stalks the nest of other bees and tries to sneak into it during construction of the cell intended for the Cuckoo bumblebee

nest-owner's egg where she will then lay her eggs, the workers then rear these eggs as if they were their own sisters and brothers.

These bees have no pollen baskets on their back legs, and do not secrete wax for nest construction.

There is no worker caste, and all cuckoo bee eggs hatch as reproductive males or females

Finding nest sites has become crucially important for our bee population. You can give them a helping hand, improve pollination in your garden and give your family a lot of pleasure.

Build a box of solid construction with removable top and two compartments, a vestibule that measures roughly 12.5cm by 15cm and serves as a staging ground where bees can poooh and set up defences from the main nesting compartment located at the back of the house.

The nesting compartment measures 20cm by 15cm and this is where queens will spend their lives.

Drill a peep hole in the back wall, with a flap, so you can sneak a look inside to see what's happening.

You can put the box almost anywhere ... in a garden, along a fence row, under hedges, by a flower bed, around mulch piles or anywhere you have seen bumble bees foraging.

Any type of cavity is likely to prove attractive to solitary bees. Try putting up old, dry, hollow stems of plants like bramble. You can use bamboo canes or even drinks straws ... something about 6-7 mm in diameter.

Tie them in a bundle and fasten them (horizontally) to a tree or post about 1.5 meters off the ground and facing south.

Or ... Get a block of untreated soft wood, say 10cm x 10mm by 20cm ... maybe a section of a tree ... drill a series of holes into it, drill LOTS of holes, 15cm deep of varying diameter from 6 to 10 mm

You can also use an old fence post ... It does not matter if it's old and battered. In fact this will look more like the natural, weather worn wood that many solitary bees nest in, just drill a series of holes 6 to 10 cm deep ... do not drill all the way through ... into the top 20cm of the post.

Make sure that holes are drilled slightly upwards into the wood and not to steep, this will prevent rain water from collecting in the tunnels.