Bombus muscorum

Bombus muscorum, commonly known as the large carder bee or moss carder bee, is a species of bumblebee in the family Apidae. The species is found throughout Eurasia in fragmented populations, but is most commonly found in the British Isles. B. muscorum is a eusocial insect. The queen is monandrous, mating with only one male after leaving a mature nest to found its own. Males mate territorially and the species is susceptible to inbreeding and bottlenecks. The species builds its nests on or just under the ground in open grassland and forages very close to the nest. In recent years, populations have significantly declined due to loss of natural habitat. B. muscorum is currently listed as vulnerable in Europe by the European Red List of Bees. B. muscourm was one of the many insect species originally described in 1758 by Carl Linnaeus in the 10th edition of Systema Naturae. It was given the binomial name Apis muscorum. The species name muscorum is the genitive plural of the Latin mūscus, meaning moss. B. muscorum is part of the order Hymenoptera, the third largest order of insects, which includes bees, wasps, ants, and sawflies. It is part of the subfamily Apinae, which contains the majority of species within the family Apidae. It is part of the tribe Bombini, which contains a single living genus Bombus, consisting entirely of bumblebees. Within Bombus, B. muscorum is part of the subgenus Thoracobombus, which includes closely relates species such Bombus atratus, Bombus dahlbomii, Bombus fervidus, Bombus morio, Bombus pensylvanicus, and Bombus transversalis.The species is further differentiated into at least seven different subspecies. These include B. muscorum sladeni and B. muscorum smithianu, found in the United Kingdom and differentiated on the basis of coat color. Certain forms of this variable taxon are considered separate species by some authors, including B. bannitus and B. pereziellus. B. muscorum is characterized by its oblong face and long tongue. The bristles of the species are ginger in color and cover the head, thorax, and abdomen. The abdomen, however, can have a darker, brownish coloring. In some subspecies, black bristles are intermixed with the ginger bristles that characterize the species. Some subspecies have an entirely black ventral side. The species is similar in appearance to the more common Bombus pascuorum. The queen has a body length 17–19 mm and a wingspan of 32–35 mm. Workers have a body length of 10–16 mm and a wingspan of 26–29 mm. Males have a body length of 13–15 mm and a wingspan of 26–29 mm. B. muscorum is widely distributed throughout Eurasia. Populations appear from Ireland in the West to Mongolia in the East. The species has been observed as far north as Scandinavia and Russia and has been spotted as far south as Crete. Populations, however, are fairly rare in all locations. Populations in the United Kingdom have declined sharply since the 1970s. Once widely distributed throughout the British Isles, distributions are now fragmented and predominantly coastal. Populations of other species, such as Bombus pascuorum, appear to be replacing B. muscorum in some parts of Northern Britain. The species is still relatively abundant in Northern Scotland. B. muscorum is classified as vulnerable in Europe by the IUCN. B. muscorum inhabits moors, grasslands, and salt marshes, where it builds its nest above ground. In the British Isles, B. muscorum nests in open landscapes near coastal areas in the lowlands. Populations are found in moorland and machair in the North. In the South, populations are found in coastal marshes, shingle, and calcareous grasslands. Nests have been found near open regions of fallowed land and man-made ditches. Colonies are small, numbering between 20 and 100 workers. B. muscorum is polylectic, the diet of the species depends on the surrounding area. The species has a strong preference for flowers of the families Fabaceae, Scrophulariaceae, Lamiaceae, and Asteraceae. Common food sources include clover, bird's-foot trefoil, vetches, and thistles. Flowers with long corollas are especially dependent on the long-tongued species. A number of new queens are produced in the last brood of the summer colony. These queens mate and then hibernate for an average of 9 months. From March to May, these queens emerge from hibernation to search for nesting sites. After a suitable site is found, the queen lays a small batch of diploid eggs. Once these eggs hatch, the queen tends to the larvae until they are grown and pupate. These pupa emerge as workers. From June onward, the queen will produce a steady supply of workers. From July to September, new males and queens are present and mate.