Thirty-six hundred little flies that rewrite public health
Culicidae—mosquitoes—are some 3,600 small fly species whose Spanish/Portuguese name means “little fly.” Slender bodies, one wing pair, long legs, and piercing mouthparts define adults. Aquatic eggs, larvae, and pupae feed freshwater food webs—then blood-feeding females can ferry malaria, filariasis, and arboviruses.
Four life stages rule the cycle: egg on water, motile larva grazing algae and detritus, pupa, then flying adult. Larvae feed dragonfly nymphs, fish, and other freshwater hunters, so the same insect is both pest and prey depending on stage.
Saliva injected during bites itches; pathogens hitch from host to host in blood meals. Not every species vectors disease, but enough do to make Culicidae central to tropical medicine and temperate outbreak planning.
Adults are usually grey or black and 3 to 6 millimetres long, with narrow scaled wings; at rest they hold their front legs outward, unlike look-alike chironomid midges. In hot weather development from egg to adult can take as little as five days, or up to a month when cooler. Males gather in swarms at dawn or dusk, and each female mates only once. Nurseries range from ponds and marshes to puddles, tree holes and the water held in bromeliad leaves, and a few species such as Opifex fuscus breed in salt marshes.
Anopheles females dab eggs one by one onto the water, each cigar-shaped with side floats, laying 100 to 200 in a lifetime, while Aedes drop theirs on damp mud. Larvae breathe through an abdominal siphon, and the tumbling pupa uses a pair of breathing trumpets. Both sexes sip nectar and honeydew, but only females pierce skin; most species feed at dawn or dusk, though the Asian tiger mosquito bites by day. Females track hosts by carbon dioxide and 1-octen-3-ol, and in the human-biting form of Aedes aegypti a taste for human odour is tied to the receptor AaegOr4.
Source: Mosquito
