Population dynamics of Bryobia rubrioculus Scheuten (Acari: Tetranychidae) and its predatories in sprayed and unsprayed apple orchards in Van

Abstract

Seasonal population development of Bryobia rubrioculus Scheuten (Acari: Tetranychidae) was studied on golden delicious and starking delicious apple cultivars in three apple orchards of Van, during 2002-2003. Overwintering eggs of B. rubrioculus deposited on the bark of apple trunks began to hatch at mid May. B. rubrioculus population reached a maximum from mid June to early July. In unsprayed orchard, B. rubrioculus remained at very low levels certainly because of the presence of Kampimodromus aberrans (Oudemans). (Acari: Phytoseiidae) On the other hand, Zetzellia mali (Ewing) (Acari: Stigmaeidae) was the most abundant predator on B. rubrioculus in sprayed orchards. B. rubrioculus reached the higher population on starking delicious than that on golden delicious