The vestiture, or hairlike projections of the cuticle, in Anastrepha and Toxotrypana include macrotrichia (setae or setulae), which have an alveolus (socket), and microtrichia, which do not have an alveolus. Microtrichia are usually extremely small and cannot be seen individually except with high powered microscopes or scanning electron microscopes. They occur in patterns so that some surface areas may appear duller or pruinose versus shiny areas that lack them. Microtrichial patterns are very difficult if not impossible to see in specimens in fluid. On dry specimens they are best observed with the surface held at an oblique angle to the light source. The scutum is the largest sclerite of the mesonotum. In Tephritidae most of the thorax visible in dorsal view is the scutum (the only other parts directly visible in dorsal view are the postpronotal lobes, notopleura, scutellum, and occasionally the postnotum). The scutum is more or less rectangular and includes pre- and postsutural areas incompletely divided by the transverse suture.