The distribution and spatial dispersion patterns of citrus, Phyllocnistis citrella Stainton, leafminer eggs and larvae were assessed in an experimental lime orchard in Dade County, Florida. Significantly higher egg and larval densities were found on apical leaves on young branches compared with older, middle, and bottom leaves on young branches. The spatial dispersion pattern determined for larvae generally were aggregated on 48−70% of the sampling dates. No significant differences in egg densities were observed among the top, middle, or lower tree canopy. However, egg and larval stages were considered statistically aggregated (b > 1) within the canopy. Sample size requirements for fixed levels of precision were determined for eggs and larvae using estimated variance-mean relationships obtained from the Taylor power law regressions. The performance of the sampling plan was evaluated using resampling software. When egg densities fluctuated between 0.34 and 0.58 eggs per leaf, the performance of the sampling plan required too few samples. Performance of existing sampling plans for larvae was low when larval densities fluctuated between 0.12 and 0.16 larvae per leaf, but improved for higher densities ≥1.97 larvae per leaf. Mean samples sizes for a precision level of 0.25 were 10 leaves per tree.
Document Type: Research Article
Publication date: April 1, 1997
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Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.