These bees have powerful
mandibles (jaws) that can dig tunnels in wood. Xylocopa violacea (left), a huge
(20-23 mm long), black bee found in central and southern Europe nests in dead
wood and digs a tunnel up to 30 cm long containing 10-15 cells. This bee holds the record for laying the largest egg of any insect.
Carpenters are found in
many parts of the world, and there is a bee almost identical to this commonly found in the USA. Naturally a large number of carpenter nests in the
structural support of a building will cause some damage, but this is unusual.
One behaviour can be alarming though. The males compete with other males to
mate with females. This involves them chasing males away and chasing females to
mate. During these chases
they zoom about crashing into windows, people and anything else in their path.
Humans in the way of all this may think they are under attack, they are not,
they are just in the way. Males may also hang around waiting for adult females
to emerge, and again they behave in what might seem to us as an aggressive way,
by chasing other males away and investigating anything that gets near the exit
hole. This something may be your head, you will be buzzed around and checked
out to see if you are a rival that needs chasing away or a female that needs
mating. However there is no danger as males cannot sting, so like much male
mating behaviour it's all bluster and show.
These bees will nest in almost any cavity
which they can modify in shape with earth or other materials to suit their
requirements. Some species specialise in nesting inside snail shells, and there
is a tiny species that nests in the holes left by wood worm beetles. The
European species Osmia rufa is often found nesting in old nail holes and
in the mortar of old walls. Others, like Anthophora retusa, on the left
construct cells using clay, sand, earth and chalk, and earth mixed with wood - whatever is at hand. In towns their nests can often be found between two bricks in walls. Anthophora retusa looks like a small, dark bumblebee, but she has orange-coloured hairs on her hind legs. In the UK this bee appears in the early spring.
Below is the honey bee. It is not nearly as hairy as the bumblebee, and is usually smaller.
Above is a wasp. They have the same colouring as some bumblebees, but they do not have much hair. There are various species around the world that have the same yellow and black striped colouring, and they range in size from 10 - 30 mm long.
Wood wasp or horntail
On the left is the wood wasp or horntail. It has similar colouring to some bumblebees, and its speedy flight make it hard to see that it is not hairy. These insects do appear very frightening, but they are completely harmless. They range in size (depending on sex and species from 12 - 44 mm long.
Above, left and right are hoverflies. Some of these are excellent mimics of bumblebees. One (I don't have a photograph yet) is very furry and can even buzz like a bumblebee, but all of them have just one pair of wings.
On the left is a fly from the USA with a very long tongue (the black thing between its front legs) drinking nectar. Its behaviour is similar to bumblebees, but it has far fewer hairs, and only one pair of wings. This photograph was sent in by Leona M. Goettel, who has kindly given her permission for www.bumblebee.org to use it on this page.
On the left is a moth found in North America called Hemaris officinalis, the snowberry clearwing. Because of its hovering habit whilst drinking nectar it can be mistaken for a bumblebee. There are a number of similar day-flying moths such as the bumblebee hawkmoth in Europe which are commonly mistaken for bumblebees, mainly because they are so difficult to get a good look at. They have a wingspan of 3.2 - 5.0 cm.