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The head is slightly wider than long, too slightly longer than wide (Stannard, 1968). Ocellar setae 1 are present, though ocellar setae 3 vary in position (Mound and Marullo, 1996). Interocellar and postocular setae are often well developed (Stannard, 1968). Antennae are 8 segmented in most species, but 7 segmented in a few. Antennal segments 3 and 4 both have a forked sense cone. There are usually 4 pigmented ommatidia in each compound eye, though this feature is absent in some species. The maxillary palps are 3 segmented. There are two pairs of long setae on the anterior margin of the pronotum along with 2 pairs of large posteroangular setae (Mound and Marullo, 1996). The pronotum has a pair of long anteromarginal setae, and an extra pair of small setae between the median posteromarginal setae (Palmer et al., 1989). Species in this genus are macropterous, brachypterous, or wing polymorphic. When the forewings are fully developed the 2 veins on the forewing each have a complete row of setae. The wing scale has 5 veinal and 1 discal setae. Abdominal tergite 2 has 3 lateral marginal seta, tergites 5 to 8 have paired lateral ctenidia, with these on tergite 8 anterolateral to the spiricles. Sternite 1 has 3 anteromedial setae, and there are 3 pairs of marginal setae on sternite 7 (Mound and Marullo, 1996).