Bombus lapidarius is probably the most easily recognised species with its black body and bright orange tail. Although the queen's body is as long as that of B. terrestris she is not as heavily built (see below). Queens can appear in March, workers in May and males in June.
The workers have the same colouring as the queen, but they are much smaller; some of the early workers are no bigger than house flies. Favourite flowers include sallows, gorse, dandelions, thistles, clovers.
The males (below) have similar colouring, but with more yellow hair.
Body Lengths, queen 20-22, workers 11-16, male 14-16. Forewing lengths, queen 17 mm, worker 12 mm, male 12 mm.
The range of B. lapidarius is expanding northwards in the U. K. As a child in Aberdeen I cannot recall seeing a single individual, but now they are often the most commonly seen bumblebee.
As with all bumblebee queens Bombus lapidarius will search any dark place for a likely nesting site. The one above was found inside a duvet, and the photograph was sent in by a visitor to the site. It is quite common for queens to enter through windows and doors while searching for a nest, and they will explore round the back of your fridge, washing machine, in fact any dark place. They will come out after a while though.
Lapidarius prefer to nest underground and the base of dry stone dykes and walls are popular locations. The size of the nest can vary considerably from 300 bees to less than 100.The cuckoo species of B. lapidarius is B. rupestris. Below a Bombus lapidarius nest. Taken from The Insect Societies, by E. O. Wilson, 1972. The Belknap Press, Harvard University. This is an excellent book covering all the social insects, and has a very good chapter on bumblebees. It should be available in any good library. It shows that a bumblebee nest is not the tidy, precise affair that a honey bee hive is. Bumblebees commonly use an old rodent nest. This nest is an abandoned mouse nest. The nest is parasitized by Bombus rupestris.
Lapidarius have comparatively short tongues (see the photograph below showing a male extending his tongue) and prefer flowers that form a distinct landing platform, such as daisies, dandelions and thistles. The heads of these flowers are made up of many small florets each containing only a small quantity of nectar. While on these flowers the bees probe many times and walk around the flower rather than fly. So the bees are going for a low yield of nectar per probe, but minimum time and energy between probes.
Below is a male. His tongue is extended as he moves from floret to floret. He is brushing some debris, pollen probably, off his head and thorax with his front leg. Males do not collect pollen as they have no pollen baskets.
Most bumblebee males patrol mating circuits laying down a pheromone to attract new queens. The pheromone is used to scent-mark prominent objects (tree trunks, rocks, posts, etc) on the circuit. The circuit is marked in the morning, and after rain. The scent of some species can be detected by some humans. Usually they patrol at species specific heights. Bombus lapidarius males patrol at tree-top height. However this depends on the habitat.
The photograph of the male above shows the typical "moustache", one of the easiest ways to recognise a male bumblebee.
The excellent photograph of a Bombus lapidarius queen and male mating below was sent in by AsB. Note the size variation. Lapidarius is one of the species where there is a great range of sizes with the queen being much bigger than the workers and males. The mites on the queen will survive with her during hibernation and take up residence in her new nest the following spring. They use her as a means of transport.