This species is very closely related to M. tricincta and care is necessary to distinguish the two in collections. However, in the field, each species is usually readily identified by the flowers the bees visit. In addition, the present species is more widely distributed in Britain than its congener, being found in northern and western localities from which the other is absent.

Of the three species of Macropis which occur in western Europe, only one, M. europaea, is found in Britain. This species is unique in this country for having females which provision their nests with fatty floral oils, in addition to pollen.

A relatively recent addition to the British bee list, the first specimen having been found in West Sussex in 1984.

A rare cleptoparasitic bee which can sometimes be reared in small numbers from the stem-nests of its host, the megachiline bee Hoplitis claviventris.

Since recording began this has always been considered a rare cleptoparasitic bee, but during this century it has decreased alarmingly.

At the time of year when many bee populations are declining, M. tricincta appears to be increasing, although it is generally only to be encountered around the inconspicuous flowers of red bartsia (Odontites vernus). In such situations it can be locally abundant and, as with other Melitta species, the males are usually more in evidence than the females.

The males of this species are among the first of the solitary bees to appear in the spring, with one exceptional record as early as late February. They are shortly followed by the distinctive females.

Previously Osmia rufa (Panzer,1806). This species has gained a notorious reputation from the females' habit of excavating their nesting burrows and cells in crumbling or soft mortar joints, thereby, in time, undermining and possibly weakening the fabric of masonry. The bee also utilises existing holes. It is colloquially known as the red mortar bee or red mason bee.

A few British bees, all megachilines, habitually nest in empty snail shells; one of these is O. aurulenta (the others being O. bicolor and O. spinulosa)

This species was formerly misidentified by British authors as H. leucomelana (Kirby, 1802) (see Yarrow, 1970).