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 to the ivy bee (Colletes hederae) and the sea aster mining bee (Colletes halophilus) which are partially sympatric with C. succinctus but ecologically separate. Description Colletes succinctus is a medium-sized bee which has pale hairs on its clypeus and pale transverse bands on the thorax but with an orange, transparent band on the first tergite. It is similar to two rare related species, the ivy bee (C. hederae) and the sea aster mining bee (C. halophilus), both of which were identified as separate species from C. succinctus in 1993 and 1943 respectively. They are all, however, separated from each other by their ecology. C. succinctus measures 10mm in length. Distribution Colletes succinctus is a widespread bee occurring from the southern part of Ireland and from Portugal east through Europe into Asia, south to Iran and as far east as Tibet. In Britain it is widespread as far north as Orkney. In the southern part of its distribution it becomes more localised and is replaced by other closely related species, for example it is absent from North Africa where it appears to be replaced by Colletes intricans, another member of the succinctus species group. Habitat Colletes succinctus is found on heathland and moorland in Britain and also in Europe where there are also some populations which occur among maritime dunes and on beaches. Biology Colletes succinctus nest in aggregations which in most of its range are quite small and can be difficult to locate C. succinctus as the females will nest singly or in small groups but in northern England and Scotland they may form large, dense aggregations of nests, with one aggregation recorded in North Yorkshire made up of 60–80,000 nests which were counted along 100m of river bank. In such dense aggregations the nests can be separated by just a few centimetres. They are univoltine and the flight period is July to October. In the early part of the fight period the males swarm around the aggregation and try to mate with emerging females. Sometimes a number of males will surround a single female and they will roll around on the ground until one of the males successfully mates with the female. Once