Comparison of Sampling Techniques to Obtain Measurements of Insect Populations on Soybeans1

Abstract

Relative size estimates of populations of selected insect species on ‘Bragg‘ soybeans were determined from four 15-in. sweepnet and one groundcloth-shake sampling techniques. Comparing relative estimates to absolute populations, the groundcloth-shake sampling method was the most efficient method for sampling lepidopterous larvae. This method has a low relative variation and a high fidelity to population changes but was time consuming. Sweeping upwards against the foliage of one row was the most efficient method for sampling adult Cerotoma trifurcata (Forster) and adults and nymphs of Spissitilus festinus (Say).