EFFICIENT MONITORING OF THE DENSITY OF ADULT NORTHERN CORN ROOTWORM (COLEOPTERA: CHRYSOMELIDAE) IN HELD CORN

Abstract

Sampling statistics for adult northern corn rootworms in New York field corn are reported, with particular reference to efficient monitoring for decision-making in pest management. The most efficient sample unit of those examined was a single, entire plant. Sample sizes and associated costs required to achieve fixed levels of precision for estimates of density are reported. Because required sample sizes are density dependent, a sequential-sampling plan providing final estimates of density at preset levels of precision is developed. The method makes no assumption about the frequency distribution of insect counts, which was found to vary from field to field and with time. Disturbance caused by sampling activity may introduce a bias of unknown direction and magnitude in estimates of beetle density. Care in approaching and examining plants; should reduce this bias.