Ethology and features of the trophic activity of blood-sucking mosquitoes (Diptera, Culicidae) in the southern taiga of the Tyumen region

In the Tyumen region (Russia), the daily rhythm of mosquitoes’ trophic activity in terms of comparing the number of individuals attacking humans and animals and the distribution of mosquitoes near cattle herds has not been studied before. The research was carried out in the sub-zone of the southern taiga forest zone of the Tyumen region in 2016-2017. The southern taiga has a high level of blood-sucking mosquitoes. In June, under the canopy of the forest, the animals are subjected to a massive round-the-clock attack, but in the daily rhythm of the trophic activity of these insects there are evening (at 23 hours) and morning (at 3-7 hours) rises in numbers. At the end of July, the daily rhythm has a high evening rise in numbers (at 21-23 hours) and a slight morning (at 5-7 hours). In open pastures, mosquito activity is less long and is characterized by one large maximum in the evening. Mosquitoes attacked animals in open areas only at night from 23 to 7 hours. The number of mosquitoes attacking calves in open areas was low and lower than the average of 2.2 ± 0.23 times per person. The nature of the daily rhythm of trophic activity of flying hematophages leaves its mark on the behavior of animals and their preference for certain biotopes on the pasture. With the number of mosquitoes observed during the day in the forest (from 2 to 32 individuals), calves preferred to graze in the open area, even with a high number of horseflies, only periodically hiding in more often shrubbery for a short time. At night, the calves are kept in the paddock, snuggling up to each other, which allows to some extent to limit the number of attacking insects. In the paddock during the night rest of the animals the largest number of mosquitoes (over 66%) flies directly near the calves at an altitude from the ground up to 1.9 meters, but single individuals are found at an altitude of more than 4 meters, a distance of 5-7 meters from calves the number of mosquitoes decreases twice, and 25-30 meters - 4 times. The high concentration of mosquitoes around the animals indicates the advisability of taking protective measures against their attack when keeping calves in open pens on pastures in the evening, when keeping animals at night in premises, treatment with repellents and insecticides should be carried out in the morning before pasture. This will allow to ensure calm and free behavior of animals during grazing and a wider coverage of various pasture biotopes.