chrysops

Chrysops is a genus of flies in the family Tabanidae, commonly known as deer flies or snipe flies. The genus comprises numerous described species that occur in a wide range of habitats in temperate and tropical regions of the Old and New Worlds. Adults are typically medium to large, with eyes often vividly patterned and metallic in color.

Morphology and identification commonly center on wing venation and eye pattern. In Chrysops, males usually have holoptic eyes (meeting at the midline), while females have separated eyes. The mouthparts are adapted for cutting and sponging, and only females take blood meals, which are required for egg development; males feed mainly on nectar or plant sap.

Ecology and behavior aspects include that adults are mostly diurnal and strong fliers, frequently seen over vegetated areas near water. Females readily bite mammals, including livestock and humans, producing painful bites and serving as a pest and irritant in many settings. Nectar-feeding behavior in both sexes contributes to pollination in some habitats.

Lifecycle and development involve eggs laid in vegetation over moist or aquatic substrates. The larvae of Chrysops inhabit moist soil, leaf litter, or shallow aquatic environments and are typically predaceous on other invertebrates. Following several instars, they pupate in the damp substrate and emerge as adults.

Medical and veterinary relevance is notable in certain species, as Chrysops can transmit parasites such as the filarial worm Loa loa in parts of Africa, causing loiasis. Overall, Chrysops species are important as biting pests and as components of freshwater and damp-habitat ecosystems.