Floodwater mosquitoes / Moustiques d’inondation
There are diverse species of floodwater mosquitoes such as Aedes vexans, Ochlerotatus sticticus and Aedes cinereus. But adaptation to biotopes that are dry most of the time and are only flooded irregularly results in very similar ways of life. Contrary to house mosquitoes, flood mosquitoes lay their eggs individually and normally deposit them on moist ground (A female can produce around 100 eggs per meal of blood). However, the larvae in the developing stage don’t hatch yet. Instead, they can survive in the embryonic membrane for up to three years.
However, the larvae do not always hatch from the eggs, even if they manage to get into water. For example, low temperatures and an excessively high oxygen concentration in the water may prevent them from hatching. Important reasons: When it is cold, the development into a mature adult takes too long, the larvae would not survive in the wrong season and there are often fish and other natural enemies lurking in oxygen-rich waters.
However, when the circumstances are appropriate, for example, when rainfall pushes the ground water upwards and lets nutrient-rich puddles, small ponds and flooded meadows and fields in the spring and summer, larvae can hatch in masses almost simultaneously. If the temperature is right, the development into a mature adult only takes less than a week. In contrast to house mosquitoes, the female flood mosquitoes normally die no later than the onset of winter.