Estimation of True Species Richness of Leafhopper (Homoptera: Cicadellidae)

Abstract

Species richness is one of the most important indices ofbiodiversity, but assessing true species richness is no easy task. In this study, we tried to determine the best estimator among seven estimators: ACE, ICE, Chaol, Chao2, Jackl, Jack2, and Bootstrap methods. A total of 7,579 samplings in two census fields, Motooka and Ino, were performed during 2000 2002. Weestablished eight survey sites. Sixty-one and 56 leafhopper species were collected at Motoola and Ino, respectively. Because the standard deviations of penultimate observed species richness were zero at the six sites, such observed species richness was regarded as true species richness. Although most of the estimators were not consistent with the true species richness, ICE was the most appropriate method to estimate the true species richness. Correlation between the true species richness of leafhoppers and the observed species richness of tree species or tree + grass species was highly significant.