A Note on the Poisson Distribution in Integrated Pest Management

Abstract

Bliss and Fisher (1953) reported that both plant and animal populations have been observed to agree substantially with the negative binomial distribution (i.e., a clumped dispersion) at high population densities and with the Poisson distribution (i.e., a random dispersion) at low densities. Entomologists may fail to detect agreement with the Poisson when sampling studies are conducted among relatively high densities where an abundance of insects can be captured conveniently. However, I expect the Poisson to be encountered frequently as entomologists in integrated pest management research sample to determine non-economic insect densities. Recent examples where pest insects at densities near or below their economic thresholds appeared to be dispersed at random include Limonius spp. and Conoderus spp. wireworms in soil (Onsager 1969, Onsager and Day 1975), green cloverworm on soybean (Pedigo et al. 1972), velvet bean caterpillar on soybean (Strayer et al 1977), grasshoppers on rangeland (Onsager 1977), and red-backed cutworm on mint (Danielson and Berry 1978).