March Flies range from 2 to 15 mm in length. The dorsum of their thorax is orange, black, or orange and black. Females have small eyes, while males are holoptic. Wings range from hyaline to cloudy to black; often each wing bears a pterostigma (Fitzgerald, in Brown et al., 2010).
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Bibio sp. (West Virginia)
Bibio sp. (Panama)
American Insects site