SeasonalityChrysops fulvaster is most readily captured in late June or July.
IdentificationTeskey (1990) records that female C. fulvaster are largely dull yellow and brown, with highly mottled wings. On the head, the antennae are largely yellow, except for the darkened apical flagellomeres, and the scape is more swollen than the other antennal segments. The frons is wider than high, and more wide below; gena partly black; palpi yellow; and the clypeus is glossy yellow with a pruinose (powdery) band. The thorax has yellow hairs, with longitudinal stripes down the scutum and pleura. The legs are largely yellow, except for blackened front femora (Cole, 1969). The abdomen dorsally is grayish yellow with black spots below the scutellum; the tergites in succession posteriorly have pairs of large brown spots with yellower triangles between them. Males are smaller and much darker, but similarly patterned (Teskey 1990).
Chrysops fulvaster can be easily separated from all other Chrysops by the combination of the median prunes band on the clypeus, the scape being swollen relative to the other antennal segments, and light infuscation (darkening) along the entire posterior border of the wings (Teskey 1990).