SEASONAL CHANGES IN THE IMAGO PHYSIOLOGICAL AGE IN THE DERMACENTOR MARGINATUS (ACARI, IXODIDAE) NATURAL POPULATION IN THE CENTRAL CISCAUCASIA

The article discusses the seasonal changes in the age composition (physiological age) of imagoes of Dermacentor marginatus ticks natural populations. To determine the physiological age, we used 1477 hungry imagoes of D. marginatus, collected on a flannel flag, under the conditions of a stationary observation site. During the entire observation period, ticks of the third physiological age prevailed. Wintering imagoes include ticks of third and fourth physiological ages. In April, at the peak of activity, the nucleus of the population is made up of ticks of second and third physiological age. A small part of the population during this period is made up of individuals of fourth physiological age. In May, the percentage of recently activated individuals decreases markedly. In collections of this period, strongly emaciated individuals of fourth physiological age predominate. The summer population of ticks is represented by individuals of the third and fourth physiological ages. Their share is over 90%. Individuals of second physiological age were found by us only in early June and late August. In autumn, the bulk of the population is also represented by individuals of third and fourth physiological ages. Keywords: imagoes, Ixodes ticks, Dermacentor marginatus, Central Ciscaucasia, physiological age, age composition