Hidden blood is a rare species of mosquito. It is dangerous to humans and can carry diseases. The first information about them was received back in the 20th century. The insects were found in different regions of Russia and Africa. Found in the tropics of the Old World, Northern and Western Hemispheres. Overwintering colonies are found in water, larval areas are inhabited by plants, and adults can be found indoors. The first mention of these mosquitoes occurs in 1955, when L. Ditmar in the journal “Red List of Insects” reported the discovery of large insects (up to 9 cm) found in Latvia. In the following years they began to meet in other parts of Russia. However, the species was described only in the 80s. The insects were given the name “blood mosquito” - Aedes taeniorhynchus, and it was reported that they differ from their tropical relatives in size. Because of this, they have avoided widespread study due to their danger to humans. Inhabiting subtropical forests along with tropical species, they carry in the second half of May - early June the largest number of infections that affect the south of Russia: O'Neill fever, Bancroft fever, Donovan fever, Crimean-Congo fever, and yellow fever. Transmission by mosquito bites and preservation