Apart from dragonflies, few insects catch our attention when we observe a body of water. This is a big mistake, because this little six-legged world is very fascinating...
Specificities of aquatic insects
Many insects live in contact with water. Essential to the ecosystem of ponds, pools and rivers, they help maintain a natural balance in these particular environments. Some of them, such as mosquito larvae, feed on bacteria or small particles suspended in the water, others, such as dragonflies or dytids (Dysticidae), carnivorous, eat living prey, and still others, such as Hydrophiles or Coleoptera, voraciously devour aquatic plants.
These insects have the specificity of seeking out wetlands, they are fond of banks, some live under stones, others find shelter in dead branches, others will spend their entire lives in water. Thirteen orders of insects share the aquatic environment but only five have species that live exclusively in water, such as the dytics and water bugs.
In their larval state, many insects develop underwater; this is the case of the dragonfly which will take two years to emerge from the water to take flight or the mosquito and the gyridinae beetles.
A well-oiled food chain
As we have seen, aquatic insects feed in a variety of ways and thus participate in the ecosystem of the water bodies where they live. But they are also part of a very organized food chain, and serve as food to many predators. Flying insects are of particular interest to birds, but also to amphibians. The larvae and insects living constantly in the water will be consumed by carnivorous fish, ducks or herons.
Some common aquatic animals
- The gerris, better known as the water spider. Very common, it glides gracefully on the surface of calm waters with small hairs waterproofed by a thin oily film present at each end of its legs.
- The nepus, otherwise called bug or water scorpion is an insect that moves at the bottom of stagnant water, it is very common in these environments.
- The dragonfly and its variants. Well known, it spends its youth under water in the larval state to transform into a formidable flying predator during its adult life.
- The mosquito is also born and transformed in water, going through four stages of growth (egg, larva, nymph and adult) in a record time varying from 10 to 15 days depending on climatic conditions and species.
- The notonect or water bee is a water bug that swims backwards and whose bite can be painful if handled without precaution.
- The linear ranate resembles a phasma, it is a species of bug that uses its front legs to capture its prey that it will empty with its powerful rostrum.
- The fringe dytique is a common beetle that can exceed 3cm. It can attack larvae of amphibians or fish.
- The mayfly is well known by its short life and its larva which is aquatic.
- The chironoma is a small insect resembling mosquitoes but which does not bite. The adults gather at the end of the day to form characteristic swirling clouds at the time of reproduction. Its larva, the bloodworm, is well known especially to aquarists.
