The curved row of bristles on the meron (=hypopleuron). The meron is the triangular(ish) plate on the side of the thorax above and between the mid and hind coxae (the very basal segment of the legs). The presence of meral bristles distinguishes the Calliphoridae, Sarcophagidae, Rhinophoridae and Tachinidae (which have them) from the Muscidae, Scathophagidae, Anthomyiidae and Faniidae (which don't). The easiest way to find the meral bristles is to find the posterior thoracic spiracle, then look a little below and in front of it.
Links: http://www.nku.ed...milies.htm First couplet.
Tried to attach an image to a forum post. jpg, 32kB, 72dpi, no blanks, ... File name is correctly displayed, but when I click "Preview Thread" it just vanishes. Help!