Culicinae
The Culicinae are the most extensive subfamily of mosquitoes (Culicidae) and have species in every continent except Antarctica, but are highly concentrated in tropical areas. Mosquitoes are best known as parasites to many vertebrate animals and vectors for disease. They are holometabolous insects, and most species lay their eggs in stagnant water, to benefit their aquatic larval stage.
The subfamily Culicinae is the largest subfamily of Culicidae, a family of Nematocera dipterans. There are 3,046 species of Culicinae mosquitoes, in 108 genera and 11 tribes. Members of the Culicinae subfamily are small flies with fore wings for flight and hind wings reduced to halteres for balance. The mosquitoes also have long, slender, legs and proboscis-style mouth parts for feeding on vertebrate blood or plant fluids. Only the females are blood feeders, requiring a high quality protein meal before they can oviposit. Because the mosquitoes are well adapted for finding hosts, the females can move quickly from one blood meal to another, and when injecting their saliva, can inject pathogens picked up from other hosts and thus efficiently spread disease.
Culicinae mosquitoes are holometabolous, going through four distinct life stages: egg, larva, pupa, and adult. The duration of each stage is species-specific, but all Culicinae mosquitoes are multivoltine. The egg, larval, and pupal stages are aquatic. Adults leave the water by flight to find plants or vertebrates on which to feed. Oviposition can occur in natural reservoirs of salt water or fresh water, or temporary pools, but oviposition sites are generally stagnant. All Psorophora and some Aedesspecies oviposit on soil where the eggs remain, unhatched, till flooded. Many species associate closely with humans, using accumulated ground water in developed areas for oviposition. Some species use plant cavities for oviposition. These species can, as larvae, drill into the plant for air.
Culicinae eggs are laid in groups by adult females, often numbering over a hundred. Most species lay the eggs on the surface of stagnant water. The female lays the eggs vertically and side by side, held together by a sticky substance excreted to coat the eggs, head end down, creating an egg raft that is convex below and concave above with ends that are typically upturned. Species that use this form of egg-laying typically hatch as first instar larvae within a few hours of laying. Oviposition on the surface of stagnant water is most common, but some species of Aedes and all Psorophoradeposit their eggs in areas that will flood. Eggs are laid and embryological development occurs, but the eggs do not hatch till flooded. After flooding, the eggs will hatch within two to three days.
