Trilikauskas L.A. 2017. [Structure and dynamics of a harvestmen population (Arachnida, Opiliones) in chernevaya taiga of the Shorskii Nature National Park, Russia] // Euroasian Entomological Journal. Vol.16. No.5: 450–456 [in Russian, with English summary].
Institute of Systematics and Ecology of Animals, Russian Academy of Science, Siberian Branch, Frunze Str. 11, Novosibirsk 630091 Russia.
ABSTRACT. The structure and seasonal dynamics of a harvestmen population was studied in the chernevaya taiga of the Shorskii National Park (Gornaya Shoriya) in 2014–2016. Collection and quantification of harvestmen was carried out by pit-fall traps. More than 1300 trap-days were undertaken and more than 3000 individuals of harvestmen were collected. Five species of inhabit the chernevaya taiga of the study area. The ground-living harvestmen population is essentially Oligolophus tridens (C.L. Koch, 1836) and Sabacon sergeidedicatum Martens, 1989. Acanthomegabunus sibiricus Tsurusaki, Tchemeris et Logunov, 2000 and Mitopus morio (Fabricius, 1779) are found for only a part of their life cycle on the soil surface, the former also found on tree trunks and the adult stage of the latter inhabiting grass and the crowns of shrubs. During the whole period of activity of the harvestmen, high values of dynamic density and share in the general population structure of ground arthropods are observed. The average value of the dynamic density for the entire period of observation was 293.6 individuals per 100 trap-days. The average proportion in the general population structure of ground-living arthropods during the work was 54.5%. The season of Opiliones activity in the study area begins before the snow is completely melted and continues until the snow falls again. In the chernevaya taiga, the seasonal dynamics of harvestmen is represented by a process of dominant species change based on differences in life cycles and spatial distribution of the species occurring there. At the beginning of seasonal activity, the overwintered adult specimens of Sabacon sergeidedicatum and the juvenile Mitopus morio formed the basis of the harvestmen population. By the middle of summer more than half of the herpetobiont harvestmen population is young Oligolophus tridens that have emerged from overwintered eggs. In autumn, the population of harvestmen consists mainly of adult specimens of Oligolophus tridens and Sabacon sergeidedicatum.
KEY WORDS: harvestmen, structure, dynamics, population, dynamic density, season of activity.