Distribution of Amblyseius manihoti (Acari, Phytoseiidae) on manioc and development of sampling plan

Sampling plans were developed for Amblyseius manihoti, a predator of the ca ssava green mite Mononychellus progresivus Doreste (Acari, Tetranychidae). Analysis of intra-plant distribution showed a more stable and constant dist ribution of A. manihoti on the leaves 9-12 (numbering starting from the fir st fully developed leaf), hence leaves belonging to this stratum were chose n as the sampling unit. Within this unit, A. manihoti displayed aggregated distributions between plants. The proposed binomial and the enumerative sam pling procedures permitted reliable estimates of A. manihoti densities. For population monitoring, 100 sample units per field were sufficient to provi de satisfactory estimates of densities.