THE SEASONAL DYNAMICS AND SEX-RATIO OF A POPULATION OF THE BUTTERFLY BOLORIA-AQUILONARIS (LEPIDOPTERA, NYMPHALIDAE)

A population of Boloria aquilonaris was studied during two seasons in southern Karelia. A mark-recapture technique was used to study image. The demographic parameters in the population were estimated by Jolly's stochastic model. The butterflies flew during 4-5 weeks; high numbers of the population were persisting for 1 week. Adult males emerged and vanished a few days before females. In the time of the flying period sex ratio was changing: males were more abundant in the beginning and females were more abundant in the end. The estimates of parameters des cribing daily changes of numbers were similar in males and females. Th e total numbers of males was more than those of females. In reduction of the population total numbers asymmetry in sex ratio increased: male s become more abundant. One of the possible self-regulation mechanisms of the population numbers is suggested with respect to reproductive s trategy.