Mosquito

Lore & Background

The mosquito lifecycle consists of four stages: egg, larva, pupa, and adult. Eggs are laid on the water surface; they hatch into motile larvae that feed on aquatic algae and organic material. These larvae are important food sources for many freshwater animals, such as dragonfly nymphs, many fish, and some birds. Adult females of many species have mouthparts adapted to pierce the skin of a host and feed on blood of a wide range of vertebrate hosts, and some invertebrates, primarily other arthropods. Some species only produce eggs after a blood meal. The mosquito's saliva is transferred to the host during the bite, and can cause an itchy rash. In addition, blood-feeding species can ingest pathogens while biting and transmit them to other hosts. Those species include vectors of parasitic diseases such as malaria and filariasis, and arboviral diseases such as yellow fever and dengue fever. By transmitting diseases, mosquitoes cause the deaths of over one million people each year.

In Their Own Story

The humid air of the mangrove swamp hung heavy at twilight, thick with the scent of salt and rotting vegetation. A female Culex mosquito hovered in absolute silence, her wings a blur beating so fast they vanished from sight. She felt it first—a distant tremor in the air, a warm plume of carbon dioxide drifting down from the sleeping bird perched on a dead branch above. Descending with ghostly precision, she rode the wind currents rather than fighting them, avoiding any vibration that might betray her approach. Her compound eyes locked onto the heat signature of the bird's neck, glowing like a beacon against the dim green gloom. With a delicate, almost reverent touch, she landed, her legs absorbing the host's subtle movements. The proboscis unfurled, a needle-sharp spear piercing the thin skin to find the pulse beneath. She fed in silence, a tiny architect of survival, unaware that her next bite might carry a pathogen to a distant village, or that her own life hung on this single meal.

Reader's Guide

Like all flies, mosquitoes go through four stages in their lifecycles: egg, larva, pupa, and adult. The first three stages—egg, larva, and pupa—are largely aquatic, the eggs usually being laid in stagnant water. They hatch to become larvae, which feed, grow, and molt until they change into pupae. The adult mosquito emerges from the mature pupa as it floats at the water surface. Mosquitoes have adult lifespans ranging from as short as a week to around a month. Some species overwinter as adults in diapause. Mosquitoes have one pair of wings, with distinct scales on the surface. Their wings are long and narrow, while the legs are long and thin. The body, usually grey or black, is slender, and typically 3–6 mm long. When at rest, mosquitoes hold their first pair of legs outwards, whereas the somewhat similar Chironomid midges hold these legs forwards. Anopheles mosquitoes can fly for up to four hours continuously at , traveling up to in a night. Males beat their wings between 450 and 600 times per second, driven indirectly by muscles which vibrate the thorax. Mosquitoes are mainly small flies; the largest are in the genus Toxorhynchites, at up to in length and in wingspan. Those in the genus Aedes are much smaller, with a wingspan of . Mosquitoes can develop from egg to adult in hot weather in as few as five days, but it may take up to a month. At dawn or dusk, within days of pupating, males assemble in swarms, mating when females fly in. The female mates only once in her lifetime, attracted by the pheromones emitted by the male. In species that need blood for the eggs to develop, the female finds a host and drinks a full meal of blood. She then rests for two or three days to digest the meal and allow her eggs to develop. She is then ready to lay the eggs and repeat the cycle of feeding and laying. Females can live for up to three weeks in the wild, depending on temperature, humidity, their ability to obtain a blood meal, and avoiding being killed by their vertebrate hosts. The eggs of most mosquitoes are laid in stagnant water, which may be a pond, a marsh, a temporary puddle, a water-filled hole in a tree, or the water-trapping leaf axils of a bromeliad. Some lay near the water's edge while others attach their eggs to aquatic plants. A few, like Opifex fuscus, can breed in salt-marshes. Wyeomyia smithii breeds in the pitchers of pitcher plants, its larvae f

Did You Know?

• All mosquitoes drink nectar from flowers; females of many species have adapted to also drink blood.
• The mosquito's saliva can cause an itchy rash.
• By transmitting diseases, mosquitoes cause the deaths of over one million people each year.
• Some species, such as the Asian tiger mosquito, are known to fly and feed during daytime.