Comparison of Sampling Techniques for the European Red Mite,Panonychus ulmi(Koch) (Acari: Tetranychidae) and the Apple Rust Mite,Aculus schlechtendali(Nalepa) (Acari: Eriophyidae)

Several methods were tested for estimating population size of two phytophagous mites on the apple cultivars Aroma, Summerred and Gravenstein. The washing technique was rated as most efficient for estimating the Panonychus ulmi population. Counting one quarter of the total number of mites in the sample gave a sufficiently precise estimate of the P. ulmi population. The mites are easily washed off and are well preserved for further study. The brushing technique was more efficient than direct counting of Aculus schlechtendali, and is the better way to handle an extensive sampling programme.