Young larvae are difficult to see because they are light colored or nearly transparent and only about 3 mm long. Mature larvae, on the other hand, are usually greenish-brown or brown and up to 10 mm long. The head is distinct and usually dark on all four instars. Upon close inspection, most of these elongate larvae are quite hairy. Some breed only in salt water, others only in fresh water.
Mosquitoes are usually most numerous in coastal counties.
There are approximately 50 species of mosquitoes in North Carolina. Most female mosquitoes prefer warm-blooded animals, including people, birds, and livestock, although some species prefer to feed on amphibians and reptiles. In some coastal resort areas, mosquitoes severely hamper outdoor activities and thereby influence the area's economic stability. Less often, they are vectors of disease. Of the human diseases known to be caused by disease organisms transmitted by mosquitoes, malaria, yellow fever, and several kinds of encephalitis have been reported in North Carolina.