Sampling of Diaphorina citri (Homoptera: Psyllidae) on orange jessamine in southern Florida

Dispersion indices and related statistics of Asian citrus psyllid, Diaphorina citri Kuwayama, on orange jessamine [Murraya paniculata (L.) Jack] shoots in southern Florida from 1998 to 1999 were determined with 235 data sets and used to develop sampling plans. Three regression models, Taylor's power law, Iwao's patchiness regression, and k=c+dm[k=m2/(S2-m)] (where k is the parameter for the negative binomial distribution) were used to analyze the data. Taylor's power law (a = 0.3407 ± 0.03, b = 1.2971 ± 0.03, r2=0.88) fit the data better than Iwao's model (α = -0.3217 ± 0.12, ß = 1.6979 ± 0.06, r2=0.76). Taylor's b and Iwao's ß were both significantly > 1, indicating that D. citri populations were aggregated. Iwao's α was significantly < 0, indicating that the basic distribution component of D. citri was the individual insect. The slope d (0.7489 ± 0.48) was indistinguishable from 0, indicating the existence of a common k (estimated as 1.2741). The incidence (P1, proportion infested) and mean density (m) relationship was developed by negative binomial distribution (NBD) basis and Nachman's model [ln (m) = 0.2277 + 1.2444 ln (-ln (P0)] (where P0= Proportion of uninfested sampling units in a sample). The NBD was appropriate for studying D. citri distribution based on comparison of NBD basis and Nachman's models. The relationship to determine sample sizes for fixed levels of precision and fixed-precision-level stop lines for sequential sampling was also developed. /// Índices de dispersión y estadísticas relacionadas con el psila de cítrico Asiático, Diaphorina citri Kuwayama, en brotes de Muralla paniculata (L.) Jack en el Sur de Florida entre 1998 y 1999 fueron determinados con 235 conjuntos de datos y usados para el desarrollo de planes de muestreo. Tres modelos de regresión, la ley de poder Taylor, la regresión Iwao, y k=c+dm[k=m2/(S2-m)] (donde k es el parámetro para la distribución binomial negativa) fueron usados para analizar los datos. La ley de poder Taylor (a = 0,3407 ± 0,12, b = 1,2971 ± 0,03, r2=0,88) encaja los datos mejor que el modelo de Iwao (α = -0,3217 ± 0,12, β = 1,6979 ± 0,06, r2=0,76). La b de Taylor y el β de Iwao fueron ambos significativamente > 1, indicando que poblaciones de D. citri fueron agregadas. El α fue significativamente < 0, indicando que el componente básico de distribución de D. citri era el insecto individual. La pendiente d (0,7489 ± 0,48) fue indistinguible de 0, indicando la existencia de una k en común (estimada a 1,