Do winter mosquitoes drink blood and are these insects dangerous for humans? 
So, snow falls on the ground, insects fall asleep, wake up... insects! Did you really think that the most successful class of land animals would not be able to conquer ecological niches that are only vacated in winter? It can, and how! Winter trichocerid mosquitoes, which swarm from November to March, prove this by their mere existence.
These guys are absolutely not dangerous to humans. They don’t spread parasites, they don’t invade houses, and they are not interested in blood in any form. All 160 species of insects do not feed at all as adults: they live on reserves from the larval stage. In essence, an adult insect is a short-lived drone, whose task is to drop the larval landing force to a new location. 
Trichocerides begin to reproduce when temperatures reach near zero - in autumn or spring. But especially repelled mosquitoes fly out from under the snow right in the middle of winter, during thaws. Unnoticeable individually (less than a centimeter in length!), they swarm in the rays of the sun to gain energy and save on heating costs. And multiply, of course. 
If you walk through the forest during the thaw, look around, winter mosquitoes are nearby!
The further fate of the males does not concern us or evolution. They fulfilled their role. But for the females the hardest part begins: they need to avoid freezing to death in the next 3-5 days while the eggs mature. Insects are quite resistant to cold weather. But -5°C is tantamount to death for them. Therefore, they keep their organs away from ice and snow. Literally. Their legs are much longer than the legs of blood-sucking mosquitoes, just in order to raise their body as high as possible above the snowdrifts. 
To be fair, it is worth noting that not all winter mosquitoes suffer from the cold. Yes, most of the species graze in the Holarctic - the region north of Mexico, the Sahara and the Asian jungle. However, several dozen species also live in southern regions, including Australia and South America. But even there, trichocerids fly out in cool seasons, when the activity of other insects is lower. 
Winter mosquito in New Zealand. What can you do, such are the winters there!
Regardless of the region of origin, the female lays her eggs in a pile of something rotting. There, the hatched larvae do thankless, but very useful work for the ecosystem: they process corpses, excrement and rotting vegetation into fertile soil. In addition, decomposing remains produce heat, the second most important resource in winter. 
But in northern latitudes, heat from decomposition reactions alone is not enough. Fortunately, we usually have a lot of snow, and it is an excellent heat insulator. Northern winter mosquitoes live strictly under the snowdrift cap, because the temperature there is around zero degrees. 
Irtysh, December 1, 2020. The thaw has decided to come, the winter mosquitoes have decided to fly out. And the fieldfare thrushes decided to eat them.
Trichocerids escaped into the winter to escape too much predation pressure. But it didn't help them much. In autumn and winter they are hunted by frogs, and shrews and predatory arthropods pursue them under the snow. And all small and medium-sized birds flock to the mosquitoes breeding in the middle of winter. Even fieldfare thrushes, which are not very fond of meat food, eagerly crunch on their modest shells. The winter lack of calories obliges.
0 comments
