Abstract
Based on a series of counts obtained in a paddy field of about 30 ha. divided into 6 subareas with different insecticide treatments, frequency distributions in each subarea of both the catch by suction machine for the green rice leafhopper, Nephotettix cincticeps and the number of infested stems per 10 rice hills for the rice stem borer, Chilo suppressalis were analyzed.
Statistical examination of the relationship between mean and variance for both series of distributions revealed that they can be well described by the negative binomial distributions with respective values of common κ (Figs. 1 and 2). On the basis of this result, several problems related to the method of assessing pest populations in wide-areas of paddy fields were discussed (Tables 1, 2 and 3).
