FEEDING PREFERENCE OF ZETZELLIA-MALI - DOES ABSOLUTE OR RELATIVE ABUNDANCE OF PREY MATTER MORE

The importance of the acarine predator, Zetzellia mall, in the control of phytophagous mites in apple orchards is not well understood. Zetzellia mall tends to prefer the eriophyid, Aculus schlechtendali, over the economically more significant tetranychid, Panonychus ulmi, but quite a wide range of preference values have been reported in the literature. In sets of laboratory choice trials, we determined that prey preference of this predator varies with the relative but not absolute density of its prey. We attempt to explain these results in terms of behavioural mechanisms and discuss the potential implications of our results for the effectiveness of Z. mall in the biological control of phytophagous mites in apple orchards.