An extraordinary case of leucism in male of Hylaeus sinuatus (Schenck, 1853) (Hymenoptera: Colletidae)

Summary. Leucism is one of the types of aberrant colorations. Although frequently documented in birds, bats and other vertebrate groups, leucistic bee species (especially cases in honeybee workers and bumblebees) have been reported almost exclusively in social networks. One male of a common solitary bee Hylaeus sinuatus was pan-trapped in a post-mining area in the north-western part of the Czech Republic. This specimen exhibits yellow coloration exceeding 60% of the body, in contrast to typical males with the proportion of yellow colour comprising less than 10%. The individual is an example of a very rare genetic mutation, whose cause is unknown. This is the first documented case of leucism within the genus Hylaeus and the first paper about leucistic bees.