Interactions between the citrus bud mite Aceria sheldoni (Acari: Eriophyidae) and the lemon host tree in a Mediterranean area

This study evaluated the relation between the citrus bud mite [Aceria sheldoni (Ewing)] and lemon trees [(Citruslimon(L.)Burm]intwogroves,overtwoseasonsinReggioCalabria(Italy). Randomsamplesofshootsweretaken every 10 days and the number of buds, blossoms, fruits, and leaves present on each shoot were counted. Blossoms and fruits were classified as healthy or deformed and the immature and adults stages of the citrus bud mite and associated predatory mites were counted. Observational data indicated that the citrus bud mite does not have a negative influence on the lemon harvest and that the interaction between its populations and the host plant is a mutual symbiosis in which mite populations use the buds as a resource and repay the host plant by positively regulating its productive system. In both lemon groves, three stigmaeid mites [Zetzellia mali (Ewing), Z. graeciana Gonzalez and Agistemus collyerae Gonzalez] were also collected and their density was compared with that of the A. sheldoni. Our study highlights the complexity of relations of the citrus bud mite and lemon trees, and stresses the importance of carefully determining the real influence of the citrus bud mite on host plant harvests.