Workers and queens have two
pollen baskets, one each on the outside surface of each hind leg. The pollen
basket is easy to spot; when it is empty it is a large, flat shiny area with
spiky hairs around the edge, and when it is full it contains pollen which is
often yellow, orange or red.
The leg abovewas taken from a dead terrestris queen. The pollen basket, or corbicula, is
seen at an angle, so it is actually wider than shown.
Parts of the bumblebee leg
Above is the outside of the rear leg of a worker/queen bumblebee. The claws, coxa, trochanter and femur are fairly unspecialised, and typical of those found in many insects. The outside of the tibia is concave, hairless and shiny when empty. It is bordered by a fringe of hairs, some of them are long and stiff. This forms the pollen basket or corbicula.
Pollen is pressed on to the the pollen basket when it has been collected by the combs and brushes on the inside of the legs (see the drawings and photograph below).
There are five segments to the tarsus. Segments 2, 3, and 4 are all similar. The last segment is usually a little longer than 2, 3, and 4. The first tarsal segment is large and flattened. It is called the metatarsus.