Ultrastructure of the ommatrichia in Megaselia scalaris (Loew) (Diptera: Phoridae)

Using both scanning electron microscopy (SEM) and transmission electron microscopy (TEM), the ommatrichia, or hair-like processes that are located between the facets of the compound eye, were examined on an adult male Megaselia scalaris (Loew) fly. Each ommatrichium was observed to be a tapering structure bearing a longitudinally grooved cuticle and are anchored tightly in flexible sockets. Ultrathin sectioning and TEM revealed a thick wall in the ommatrichia, and their function was proposed to be mechanoreception based on characteristics from both SEM and TEM observations.