SAMPLING DISTRIBUTIONS AND SEQUENTIAL SAMPLING FOR 3RD INSTARS OF BLACK TURFGRASS ATAENIUS, ATAENIUS-SPRETULUS (HALDEMAN), IN CONTROL TRIALS

Sampling statistics were determined for third-instar black turfgrass a taenius, Ataenius spretulus, in control trials in turfgrass. Iwao's pa tchiness regression and a quadratic model were inappropriate for model ling the mean-variance relationships. Taylor's power law was used to m odel these data and relationships were developed for counts of third i nstars. Relationships to determine sample sizes for fixed levels of pr ecision and fixed-precision-level stop lines for sequential sampling o f third-instars were also developed. Neither the ln (x + 1) transforma tion nor the Healy and Taylor transformation consistently standardised the mean-variance relationships and the appropriate transformation sh ould be selected on a case-by-case basis.