Population and seasonal dynamics of eriophyid mites in birch stands in the krušné hory mts (Czech Republic)

Abstract

Long term (1995-2007) and seasonal population dynamics of two gall mites Acalitus rudis (Canestrini) and Eriophyes leionotus (Nalepa) was examined in birch (Betula pendula Roth) stands in the Krušné hory Mts. E. leionotus showed a gradual continual increase probably affected by changes in air pollution load and food quality. A. rudis indicated a six-year cycle of population dynamics. Overwintering deutogynes of A. rudis/E.leionotus were activated from mid-April/late on April, when sum of effective temperatures reached a value of 50.8/60.5 °C, and birch buds began to burst. On the basis of seasonal dynamics, termination of the creation of erinea and galls, it is possible to qualify A. rudis and E. leionotus as monovoltine. Partial differences between the eriophyid mites in the spring induce creation of galls and their leaving in autumn are affected by the host and its response to site conditions.