Supersocieties

Leaf cutter bee © Roger Key

Like the leaf cutter bee (Megachile sp.) pictured above, the vast majority of wasp and bee species are solitary, they live and nest alone. Some species nest in aggregation. Where conditions are right for example good sites for digging nest burrows, or near good sources of food it is an advantage to live near your neighbours. Plus if you nest together you have a better collective chance of finding mates.

Some species have taken this a stage further, they evolved to become the social insects. Sociality evolved in the insects long before the vertebrates got in on the idea. Sociality in insects serves the same advantages as having a social structure in humans. Individuals can band together for a common good: the success of the nest or colony. Strength in numbers is often the name of the game when defending a nest, capturing large prey, or providing food for large numbers of young. This is where these insects have become so successful, the level of co-operation is so well developed that scientists often refer to ant colonies, not as groups of individuals, but as super-organisms'.

Here we follow Programme 5 of Life In The Undergrowth looks at the social insects - bees, ants, wasps, termites.

German wasp (Vespula germanica) © Dragiša Savic

Helpful Hornets

Hornets are the biggest wasps in the UK . They look very similar to common wasps, but are larger and are coloured brown (rather than black) and yellow. Hornets have an undeserved fearsome reputation, although large and fairly intimidating they are peaceful beasts. They will only sting humans if attacked themselves, or if the nest is threatened.

Hornet (Vespa cabro) © Ben Hamers

Hornets build papery nests in hollow trees. They have a similar life cycle to that of our common wasp. Newly-mated queens hibernate during the winter, and emerge in spring to begin building a nest. They lay eggs that hatch into sterile female workers who take over nest building and collecting food for the developing larvae. Later in the summer males and fertile females hatch. These mate and the females become next year's queens. The males, old queen and workers die in the autumn.

Hornets (Vespa cabro) © Dragiša Savic

Hornets play a part in keeping the natural balance of things in our ecosystem. Adult hornets catch lots of other insects, and spiders, to feed themselves, and the larvae. In this way they provide a service to the gardener or farmer in controlling the populations of insects that would otherwise munch on crops. The adults also feed on nectar and fruit.

Bumblebees

Common carder bee (Bombus pascuorum) © Roger Key

Bumblebees are great looking insects, they are relatively large, furry and bright stripy colours. Lazy summer's days just wouldn't be the same without the gentle buzz of bumblebees.

Not only are they pleasing to the eyes and ears, bumblebees are incredibly important. They are important pollinators of our crops, and of wild plants. Bumblebees are active for longer in the year than other bee pollinators. They are active at low temperatures, like in early spring, or in bad weather. Because of this they are considered to be more effective pollinators than honey bees. Different species of bumblebee have different length tongues, they are adapted to feed on nectar from different shapes of flowers, and for example long tongues can reach the pollen in long, deep flowers like foxgloves. If we didn't have bumblebees we would also lose some of these plant species.

Invertebrates in Danger!

Unfortunately many of the UK's bumblebees are declining. Many species have declined by more than 50% in the last 30 years, and one has become extinct. A number of factors have contributed to this decline, including the intensification of agriculture, the loss of wild places and bumblebee habitat, inappropriate land management and insensitive development.

Brownfields for Bees!

Brown-banded carder bee (Bombus humilis) © Sam Ashfield

Many of our bumblebees rely on man-made habitats like parks, and gardens for their survival, especially in towns or cities. One place where you might not expect to find wildlife is on brownfield sites. These are pieces of land that were once used for housing, or industrial development, but have been left and are now 'derelict'. When left for a number of years, these sites often revert to a naturalised state, becoming colonised by wildflowers and other wildlife.

Brownfield sites are incredibly important for UK biodiversity; they often support nationally important populations of rare and scarce invertebrates, plus other wildlife such as birds, reptiles, plants and lichens. The Brown-banded carder bee, pictured above, is found on brownfield sites in the Thames Gateway corridor in the southeast of England. This species has declined in the wider countryside and is now reliant on brownfield sites for its survival. Thanks to work by Buglife, Canvey Wick, an important brownfield site for the Brown-banded carder bee, was protected by the government's nature conservation advisors English Nature in Spring 2005, it is now a Site of Special Scientific Interest. To find out more about why brownfield sites are such an important issue for Buglife click here.

Incredible Insect Inventors!

Social insects such as ants, bees, wasps and termites have been doing many things that us humans have only 'invented' relatively recently.

• Termites invented air conditioning for their mounds millions of years ago. Termite mounds are the tallest non-human constructed buildings. The mounds have a complex structure that draws in fresh cool air and expels hot stale air so that the whole mound is ventilated.

  wasp nest (interior) © Roger Key

• Wasps invented paper, many species make their nests from incredible paper constructions.

• The first farmers on earth were not humans, they were invertebrates. Termites and leaf cutter ants both grow crops in fungus gardens, and many species of ants have aphid livestock which they protect from harm and 'milk' for their honeydew like a herd of cows!

Black ant (Lasius sp with aphids © John Feltwell