modification rarely if ever have mites in this region, while those with the glabrous area almost never lack mites, so despite its simple nature it does indeed appear to function as an acarinarium. In some cases, sister species may differ in this feature, one having an acarinarium, and one lacking it, suggesting that the trait can be lost and possibly regained. Other examples include: In the potter wasp genus Parancistrocerus, the base of the second metasomal tergite is concave, and covered by the posterior lip of the first metasomal tergite, and mites are carried in the concavity. This structure appears the same in both males and females, though it is difficult to assess whether both sexes carry mites with equal frequency. References External links Bees and mites Insect anatomy Acari Symbiosis