Dispersion Statistics and Sample Size Estimates for Tetranychus kanzawai (Acari: Tetranychidae) on Mulberry
- 1 February 1993
- journal article
- research article
- Published by Oxford University Press (OUP) in Environmental Entomology
- Vol. 22 (1) , 21-25
- https://doi.org/10.1093/ee/22.1.21
Abstract
Dispersion indices were calculated for Tetranychus kanzawai Kishida in groves of mulberry, Morns alba (L.), in Taiwan. These indices indicated a clumped distribution for the surveyed population range of T. kanzawai: 0.53–96.5 mites per leaf. However, the X2 goodness-of-fit test generally rejected the negative binomial model among trees, but accepted it within trees. The level of aggregation varied with the population density of T. kanzawai and among mulberry groves. The dispersal of spider mites is discussed as a factor affecting this parameter. Optimal sample size is estimated for various densities of T. kanzawai and error margins on the assumption of Taylor's power law and mean crowding-mean regression.Keywords
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