WHY DO MOSQUITOES DRINK BLOOD?

In this frosty fact that the basis of the ration of some animals is blood, there is nothing surprising (it is rich in nutrients, especially proteins). And there is nothing strange in the fact that some animals, in particular representatives of the family Culicidae, whom we call mosquitoes, have adapted to extract it.

Thanks to the "bloody diet" female mosquitoes were able to lay their eggs more than once in life, like many other Diptera, but several. A record number of clutches - 12 - was registered in a malarial mosquito. It is no accident that the need for blood is experienced only by female mosquitoes - males are indifferent to it, they suck out nectar and pollen from plants. There are almost no proteins, but enough carbohydrates as an energy source. However, females also go on a vegetarian diet, if there is nowhere to take blood, only in this case they can not lay eggs.



In the family, which has about three thousand species, different taste preferences. Some mosquitoes specialize in one kind of hosts, others do not care whom to bite - if only there was plenty of food. There are gourmets, fans of cold frog blood. Described even insects, attacking fish - mud-plucked jumper, traveling overland. Some tropical species are able to feed on lymphatic caterpillars. But most still prefer warm blood of birds and mammals.

To find a suitable victim, mosquitoes are assisted by sensors on antennae antennae, which are sensitive to the heat radiation emanating from the living creature, as well as to the products of its metabolism: carbon dioxide and uric acid. Since there are two antennas, the direction to the source of the blood is very precise.

The emergence and growth of megacities contributed to the emergence of new forms of mosquitoes, specializing in human blood supply, for example, the urban mosquito-sulcus Culex pipiens pipiens molestus. Recently, it was established that from one milligram of human blood, a female mosquito gives about 40 eggs, and with the same amount of bird - twice as many. Hence, the process of adaptation is only at the very beginning.

It is curious that larvae of urban mosquitoes, feasting in damp cellars on decaying organic matter, gain enough reserves to lay aside the first laying of eggs without additional blood supply. To annoy us at night with bites and a squeak they go after this. This feature allows urban mosquitoes to sustainably maintain numbers, regardless of the availability of warm-blooded victims.