Acaricidal Activity of Extracts of Juglans regia L. on Tetranychus urticae Koch (Acari: Tetranychidae)

Abstract

Two-spotted spider mite (Tetranychus urticae Koch) (Acari: Tetranychidae) is a very serious pest worldwide, causing considerable damage to vegetables, flowers and fruit crops. The application of plant extracts to control insects can be an effective alternative. In this study, the efficacy of an extract from Juglans regia L. (Juglandecaea) was tested as an alternative to conventional acaricides. Using two different methods, bioassays were used to determine the effects of varying concentrations J. regia (1%, 3%, 6%, 12%) of the extracts. Experiments were carried out using 3 cm diameter leaf disks of Phaseolus vulgaris L. In addition, the effects of the extract on mite reproduction and oviposition were investigated. As a result, in the leaf dipping method, the 12% concentration of the extract caused the highest mortality of nymph (90%) and adult (83.00%) stages. For the spraying method, the mortality of adults at the same concentration was 100%. In bioassays at lower concentrations, the adult mites laid lower numbers of eggs in comparison to the untreated mites. The highest effect occurred at concentration of 12% and the lowest effect was at 1%. The extract was no observed ovicidal effect.