A new method for sampling eriophyoid mites from architecturally complex plant structures

In this study the effectiveness of the sticky tape method of eriophyoid mite extraction (Harvey and Martin, J. Econ. Entomol. 81, 731-734, 1988) was evaluated with and without the addition of a new method - a supplementary synthetic pyrethroid spray - for estimating the critical abundance of eriophyoid mites from within architecturally complex plant structures. To do so the eriophyoid mite, Acalitus essigi (Hassan) was sampled from within the architecturally complex fruit of blackberries (Rubus fruticosus L. aggregate). Even though damage symptoms were not observed, sticky tape extraction supplemented with a synthetic pyrethroid spray was the significantly most successful method of mite extraction, with on average over twice the number of mites extracted from blackberry fruit using this method compared with sticky tape alone. Visual counts of A. essigi on the receptacle region of blackberry fruit were correlated to the number of mites extracted using the sticky tape method both with and without a spray treatment. However, due to the low numbers that were visually assessed, the use of visual methods alone appears limited.