The study of spatial distribution of the insects is fundamental to elaborate sampling plans with potential for use in integrated pest management. Field experiments were carried out for Bemisa tabaci B biotype in common bean Phaseolus vulagaris L. in a 10,000 m² area, divided in 100 equal 10 x 10 m plots, at the November and February plantings. Ten plants per plot were sampled weekly. One foliole per plant was collected and the presence-absence of whitefly nymphs was assessed on the abaxial surface. For adults, the presence-absence of the pest was observed visually on the plants. In all the samplings lower values were obtained than the unit for the variance/mean relationship, indicating a regular placing of the whitefly in the field, which was confirmed by the significant values detected for the <FONT FACE=Symbol>½</FONT>d<FONT FACE=Symbol>½</FONT>statistic and by the values lower than the unit presented by the Morisita index. The positive binomial distribution was the most suitable to represent the spatial distribution of B. tabaci biotype B in the bean crop.
Insecta; whitefly; binomial distribution; sampling
