An acarinarium is a specialized anatomical structure which is evolved to facilitate the retention of mites on the body of an organism, typically a bee or a wasp.
The term was introduced by Walter Karl Johann Roepke.
[1] The acarinarium has evolved to enhance the mutualistic relationship between the mites and the host organism.
[2] Fossil evidence of halictid bees with an acarinarium is found in the early Miocene extinct genus Oligochlora from Dominican amber deposits on Hispaniola.
[3] The presence or absence of this structure has been used as a taxonomic character.