[Attempt to establish the population and ecological characteristics of Ixodes persulcatus (Ixodidae) by the change in the physiological age of the ticks in the course of a season of activity].

Certain peculiarities of the senescence of Ixodes persulcatus population were established according to the changes in the age composition of hungry adult ticks belonging to different groups. It was found that the expenditure of reserve nutrients is irregular, this irregularity being greater in males than in females. Early in season younger ticks become active while in the second half of the season--older ones. Maximum life span of females in fir forests of western Sajans is 70 to 80 days, that of males--65 to 70 days. The average life span of females is greater than that of males. The conclusions are not precise enough that is mainly due to irregular character of senescence of ticks, to errors in representativeness, and subjectivism of the age evaluation in using qualitative criteria.