A univoltine species; late April to mid July (Else & Edwards, 2018). Stanisavljević (2000) copying Banaszak & Romasenko (1989) states the flight period is from May to July. Amiet (2004) gives a flight period in Switzerland from the end of March to the beginning of August
Parasites and predators Numerous females of the sapygid wasp Sapyga quinquepunctata were observed inspecting nest burrows of Osmia xanthomelana at Aberdovey by Mortimer (1905). F. Smith (1876) also reports that Chrysis ignita has been reared from the cocoons of this bee, but this seems unlikely, and may be based on a misidentification (possibly Chrysura radians was the real parasitoid involved).
Chrysura [as Chrysis] hirsuta is cited as a parasite on the continent (Banaszak & Romasenko, 1998). The bombyliid fly Anthrax anthrax has been reared from German nests (Enslin, 1921 [as Argyromoeba anthrax]); this is a very unlikely parasitoid of Osmia xanthomelana in Britain, being a very rare species, recorded only from two sites in Leicestershire (Oldroyd, 1969).