''Epeolus cruciger'', the red-thighed epeolus, is a species of cuckoo bee from the family Apidae. It is endemic to Europe, where its main host is the common colletes (''

Colletes succintus ''Colletes succinctus'', the common colletes or heather colletes, is a species of Palearctic mining bee from the family Colletidae. It is part of the ''succinctus'' species group within the genus '' Colletes'' and is especially closely related ...

''), although other species of '' Colletes'' mining bees have been recorded as hosts.

Description

''Epeolus cruciger'' is a small

bee Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyly, monophyletic lineage within the ...

in which the females have a reddish scutellum and tend to have entirely red legs. The fifth

sternite The sternum (pl. "sterna") is the ventral portion of a segment of an arthropod thorax or abdomen. In insects, the sterna are usually single, large sclerites, and external. However, they can sometimes be divided in two or more, in which case the ...

is straight when viewed from the side and from below it is noticeably wider than it is long. The abdomen is nearly completely reddish. The males have a dark scutellum (scutellum dark) usually have a reddish pygidium. The abdomen is black with large, paired whitish patches of flattened hair on each side. They are 6-8mm in length.

Distribution

''Epeolus cruciger'' is found in southern and central Europe as far north as Finland and is thought to be endemic to Europe. In Britain it is widespread in the southern part but becomes scarcer in the north, with one old unconfirmed record. and a more recent confirmed record in Scotland, both from

Ayrshire Ayrshire ( gd, Siorrachd Inbhir Àir, ) is a historic county and registration county in south-west Scotland, located on the shores of the Firth of Clyde. Its principal towns include Ayr, Kilmarnock and Irvine and it borders the counties of Re ...

. It is absent from Ireland. In the Netherlands it is found in the coastal dune systems while a population in the Delft estuary which was recorded for the first time in 2006 proved to be temporary and subsequently died out. However, in Belgium, there have been records of ''E. cruciger'' at least since the 1950s.

Habitat

''Epeolus cruciger'' is found in inland heaths,

moorland Moorland or moor is a type of habitat found in upland areas in temperate grasslands, savannas, and shrublands and montane grasslands and shrublands biomes, characterised by low-growing vegetation on acidic soils. Moorland, nowadays, generally ...

, dunes systems, sandpits and undercliffs. Its main host ''

'' uses ling (''

Calluna vulgaris ''Calluna vulgaris'', common heather, ling, or simply heather, is the sole species in the genus ''Calluna'' in the flowering plant family Ericaceae. It is a low-growing evergreen shrub growing to tall, or rarely to and taller, and is found wid ...

'') as its principal food plant, so this shrub is an important element in the habitat for ''E. cruciger''.

Biology

''Epeolus cruciger'' is univoltine with a flight period from the end of June to late September. It is a cleptoparasite on the nests of ''Colletes succintus'', although other hosts in the genus '' Colletes'' have been recorded, but these have not been confirmed. The adults have been recorded foraging for nectar on the flowers of clover (''

Trifolium Clover or trefoil are common names for plants of the genus ''Trifolium'' (from Latin ''tres'' 'three' + ''folium'' 'leaf'), consisting of about 300 species of flowering plants in the legume or pea family Fabaceae originating in Europe. The genus h ...

spp.''), hawkbits ('' Leontodon sp.''), ling (''Calluna vulgaris''), mint ('' Mentha''), ragwort ('' Senecio jacobaea''), sheep's-bit ('' Jasione montana''),

tansy Tansy (''Tanacetum vulgare'') is a perennial, herbaceous flowering plant in the genus ''Tanacetum'' in the aster family, native to temperate Europe and Asia. It has been introduced to other parts of the world, including North America, and in ...

('' Tanacetum vulgare''). There are no records of parasites or

predators Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...

for ''E. cruciger''.

Conservation status

''Epeolus cruciger'' is classified as near threatened by the International Union for Conservation of Nature but in Britain it is not regarded as rare or threatened and in the Netherlands it is regarded as not threatened with a stable population. but in Germany it is on the national red list as Category V.

Taxonomy

''Epeolus cruciger'' may be a lot of species with a distinct population which has an earlier flight period and is smaller in size, which utilises ''

Colletes marginatus ''Colletes marginatus'' is a species of solitary bee of the family Colletidae. The female only gather pollen from flowers of the family Fabaceae, including species like ''Trifolium arvense'', ''Melilotus albus'' and ''Melilotus officinalis '' ...

'' as a host, which may be a species in its own right, ''Epeolus marginatus''. There is also a population in northern Italy which uses the ivy bee '' Colletes hederae'', a species very closely related to ''C. succintus'', as a host, and has remained restricted to what is thought to have been its glacial refuge, while its host has spread into other parts of Europe as far apart as southern England and Cyprus.

References

{{Taxonbar, from=Q148644 Nomadinae Hymenoptera of Europe Insects described in 1799