Effect of washing and some acaricides in control of almond spider mite, Schizotetranychus smirnovi (Acari, Tetranychidae)

Abstract In this study the effect of washing (soap at the rate of 2/1000) was compared with some acaricides in control of the almond spider mite in the field conditions based on the completely randomized block design during 2009-2010. Treatments included bromopropylate (at the rate of 2/1000), hexythiazox (1/1000), fenazaquin (0.5/1000), fenpyroximate (0.5/1000), clofentizin (0.75/1000) and washing (with soap at the rate of 2/1000). Water spray was used as control. Pest population density was recorded 3, 7, 14 and 21 days after treatments. Results of the first year showed that bromopropylate had the highest mortality, while fenazaquin and clofentizin treatments caused the least mortality in the pest population at different sampling times. Washing, fenpyroximate and hexythiazox treatments ranked the second after bromopropylate. In the second year, bromopropylate and hexythiazox treatments caused the highest and lowest mortality in the mite population, respectively. Washing was not significantly different with fenazaquin, fenpyroximate and clofentizin and ranked after bromopropylate. Comparing mean mortality of the mite (adults and nymphs) in both years of study showed that there was no significant difference between washing of the infested trees and application of acaricides at different sampling times. Using this method, in addition to the pest control, can reduce the production cost, protect the natural enemies and increase the plant photosynthesis.