Females typically require a blood meal for development of eggs, but those of a few species are capable of producing an initial batch of eggs without feeding. Eggs are laid in a mass on various moist surfaces and hatch in 2-7 days. There are four larval stages (Figure 2), with larval development completed in about two weeks to a year or more, depending on temperature and food supply. The pupal stage typically is formed in the same site as the last larval stage, and adults emerge in 2-3 days. Adults can live for two to seven weeks. Laboratory and field studies suggest that biting midges may complete two or more generations per calendar year. Last stage larvae over-winter and pupate the following spring to early summer.
Biting midge larvae develop in a variety of semi-aquatic or aquatic habitats, depending on the species. For example, larvae of some species of Culicoides are truly aquatic, developing both in streams and ponds, but those of most species are found in organically rich, semi-aquatic sites such as marshes, bogs, tree holes, and saturated rotting wood. Larvae of Culicoides species that are biting pests of livestock develop in saturated soil of wastewater ponds and sepage from watering troughs, both typically enriched with livestock manure. Larvae of Leptoconops species that bite humans develop in moist soil fissures, including in many areas of the arid western U. S. Larvae of Forcipomyia species develop in mosses, algae, rotting logs, and also in moist soil beneath fecal pats of cattle.