Development and Validation of a Fixed-Precision Sequential Sampling Plan for Aster Leafhopper (Homoptera: Cicadellidae) in Carrot

Abstract

From 1995 to 1997, data sets (351) were collected from 30 fields in central and southern Minnesota to determine the most efficient, fixed-precision, sequential sampling plan for density estimation of aster leafhopper, Macrosteles quadrilineatus Forbes, in carrot, Daucus carola (L.). Conventional and organic farms were sampled to obtain a range of leafhopper densities likely to be encountered with various management practices. Densities ranged from 0.01 to 6.97 leafhoppers per sweep. Taylor's a and b parameters were estimated fromp 266 data sets and used in conjunction W ith 15 independent data sets to validate the sampling plan with resampling software, The results showed that, for a density range of 0.01-1.61 leafhoppers per sweep, 20 samples of 10 sweeps each must be taken to achieve an average precision level of 0.25 (SE/mean). In subsequent analyses, results were partitioned into low ( 0.25) Final density can be compared with the aster yellows index for control guidelines.