Excavator: Ground. A eusocial species. The overwintered gynes normally nest in crowded and occasionally extensive aggregations, usually in level or gently sloping, bare or sparsely vegetated soils. Some of these are traditional sites, having been used for nesting for many years. Sites at the top of beaches are sometimes deluged by seawater during winter storms (Packer & Knerer, 1985). The development of this bee is probably the most extensively documented of any Palaearctic halictine species. Important references describing its biology include E. Stöckhert (1923), Legewie (1925), Noll (1931), Bonelli (1948), Michener (1974), and Westrich (1989).
Colonies of L. malachurum at Eichkogl were strictly monogynous, though they may have contained alien workers. They therefore resemble those at Tubingen, where only monogyny was detected (Paxton et al., 2002). Reports of polygyny in L. malachurum are currently confined to one population in Greece (Wyman and Richards, 2003; Richards et al., 2005), the south of the range of the species, and may reflect the large worker complement that colonies attain with three phases of worker brood production, rather than two phases (Eichkogl) or one (Tubingen) of other genotyped populations.
Weissmann et al (2017), working on the Azores, state that the species is ground nesting (mostly in compacted soil), often in large aggregations;
sentinel bee closes access with her head.