Genus name Chrysopilus means "golden-hair" and thoracicus refers to the golden patch on the thorax, presumably.
Size
male: 10-12 mm; female: 10-13 mm (Leonard, 1930)
Identification
Larger than a house fly with distinctive smoky-colored wings and gold patch on upper thorax.
Another recognized species, Chrysopilus davisi, is very similar but lacks the silvery hairs on the abdomen. C. thoracicus and C. davisi seem to represented here, but they could be the same species. See photo below for what is possibly an interspecific pairing:
Range
Eastern North America
Habitat
Deciduous woodlands
Season
Spring. April-May (North Carolina).
Food
Adults are alleged to be predatory on other insects, but they may feed little (observations by BugGuide members).
Life Cycle
Details unknown. This fly is observed in early to mid-spring perched quietly on low vegetation in deciduous woodlands.
Remarks
The coloration (dark wings, gold thorax)is perhaps mimicry of a hymenopteran. Another Chrysopilus species (see Milne and Milne, below) appears to be a very good hymenopteran mimic, with a prominently striped abdomen.
Leonard, M.D. 1930. A revision of the dipterous family Rhagionidae (Leptidae) in the United States and Canada. Memoirs of the American Entomological Society 7: 1-181 (BHL link)