Ecology of black beetle, <i>Heteronychus arator</i> (Coleoptera: Sarabaeidae)–population sampling

Abstract

Abstract A system of sampling black beetle populations to obtain estimates of numbers for use in population dynamics studies was investigated. Dispersion characteristics and the precision of the sampling data were established. The very dynamic nature of the life cycle, which gave rise to considerable overlap of the life stages on most sampling occasions, prevented age‐specific sampling. Population dispersion in December did not depart significantly from that described by the negative binomial model. In February, March, May, and June, dispersion was random, and fitted the Poisson series. The relationship of sample variance to sample mean and mean crowding to mean density confirmed the change in population dispersion from aggregated to random between December and June, as development proceeded from egg to adult. Lowest relative standard errors of the sample mean were achieved at higher population densities and in samples taken in February. The significance of these findings to the study of black beetle population dynamics is discussed.