LAUSR

Abstract Citricola scale, [Coccus pseudomagnoliarum (Kuwana)], is a key pest of citrus requiring insecticide control in areas where biological control is ineffective. Here we quantified the relationship between C. pseudomagnoliarum density and Valencia orange (Citrus sinensis L. Osbeck) yield and sooty mold contamination to inform pest action thresholds. Two field experiments documented significant effects of adult or nymphal C. pseudomagnoliarum densities on fruit yield and sooty mold. Adults generally had more pronounced effects, reducing average tree yield by up to 43% and increasing sooty mold prevalence by at least 45%. Analyses estimated significant effects of C. pseudomagnoliarum at densities less than 0.1 adults/branch or 1.0 nymph/leaf. These results suggest a decrease in the current threshold of 1.0 for adults/branch and may be warranted to minimize C. pseudomagnoliarum damage.