Estimation of Absolute Larval Densities and Calibration of Relative Sampling Methods for Velvetbean Caterpillar, Anticarsia gemmatalis (Hübner) in Soybean

Abstract

Two methods for estimating absolute densities of three size classes of velvetbean caterpillar, Anticarsia gemmatalis (Hubner) (Lepidoptera: Noctuidae), larvae in soybean fields are described and evaluated. These absolute-density estimation methods, sweep-net and ground-cloth, were used to sample field populations of velvetbean caterpillar larvae in soybean. These data were used to derive equations converting sweep-net and ground-cloth larval density estimates to absolute-density estimates. Calibration equations for converting sweep-net estimates to ground-cloth estimates are also presented.