Sampling procedures for spittlebug adults in pastures of Brachiaria decumbens.

NILAKHE, S. S.; SILVA, A. A. da; SOUZA FILHO, J. A. G. de

Sampling procedures for spittlebug adults in pastures of Brachiaria decumbens.

Autores

NILAKHE, S. S.

SILVA, A. A. da

SOUZA FILHO, J. A. G. de

Descripción

A sampling study of spittlebug adults in pastures of Brachiaria decumbens was conduced to find an appropriate number of sweep-net sweeps/sample. Considering the relative variation (SE/X) X 100, and the total number of sweeps in the sampling, 10 sweeps/sample were found to be better than 5,20 our 40. The number of samples required for a particular level of relative variation at population densities>16 spittlebug adults/10 sweeps remained the same, whereas at densities<16, the number increased inversely. A regression model to convert relative estimates obtained by sweep-net method to the absolute estimate was presented. Considering the degree of precision and the time spent in sampling, the sweep-net method was superior to cage method. The distribution pattern of numbers of spittlebug adults in samples of 10 sweep-net sweeps, generally fitted the poisson series. A sequential plan presented here would reduce the sampling time over the conventional (fixed sample numbers) sampling.
Título em português: Procedimento de amostragem de adultos de cigarrinhas em pastagens de Brachiaria decumbens.