The queens Bombus terrestris and B. lucorum are usually the first to emerge in the spring. B. terrestris queens are the largest bumblebees we have in the UK. It is fairly easy to differentiate between B. terrestris and B. lucorum queens as the yellow thorax hairs of terrestris are more dull orangey while those of lucorum are more lemony, and B. terrestris has a brownish orange tip to her abdomen while B. lucorum's is white.

The workers and males of these two species are impossible to tell apart unless they are dissected.The workers look like smaller versions of the lucorum queen. See the worker on the left. The size range can vary quite a lot, but usually the smaller workers are from the earliest laid eggs. The males have a many more yellow hairs, and a distinctive yellow nose. Of course they do not usually emerge until about August. Both of these species make their nests in the ground, usually in old mouse nests, and preferably facing south to keep the nest warm, though B. terrestris tends to prefer shadier sites. Generally the nests of B. terrestris have a deeper and longer tunnel that those of B. lucorum. Successful nests can have as many as 250 workers. The cuckoo species of B. lucorum is B. bohemicus, and the cuckoo species of B. terrestris is B. vestalis.

Both species have comparatively short tongues for bumblebees, so they tend to forage on flowers with short corollas and daisy-type flowers. However they are accomplished nectar robbers. When they find a flower where the nectar is too deep down the corolla for them to reach they bite a hole near the base of the corolla and push their tongue through and drink the nectar. This can often be seen on vetches. Other bumblebees will use the hole, and late in the year I have even seen honey bees and wasps use holes made by bumblebees. One of the best examples of nectar robbing is to be seen in the Cruickshank Botanical Gardens of the University of Aberdeen. Between the back of the Zoology building and the benches is a strawberry tree (Arbutus unedo), it has white, bell-shaped flowers with nectaries just out of reach of B. terrestris and B. lucorum. By the end of summer almost all of the thousands of flowers will have a hole at the base, and this hole will be used by all short-tongued nectar gathering insects, especially wasps. When B. terrestris and B. lucorum aren't robbing flowers without pollinating them they are very useful pollinators of fruit trees, raspberries and blueberries. They also favour any flower with nectar or pollen that is easy to get at. The worker above right is foraging on mimosa, and these left and right are brushing the pollen off the anthers of a large water lily flower.

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