A Method for Observing Below-ground Pest-Predator Interactions in Corn Agroecosystems

Abstract

A method was developed and evaluated in no-tillage corn fields to investigate the possibility of direct observations of below-ground pest-predator interactions. Rectangular-shaped plexiglass plates were buried parallel to each plant so that roots and a stage of southern corn rootworm (SCR), Diabrotica undecimpunctata howardi Barber, .could be observed. These direct observations through plexiglass demonstrated that five predators were able to remove large numbers of SCR stages; however, only one arthropod (Lasius spp., Formicidae) was an important predator of all SCR stages. Most arthropods successfully attacked only one or two SCR stages. This method enabled detailed observations of below-ground pest-predator interactions and indicated which soil arthropods were important SCR predators. This method elucidated many aspects of SCR-predator activity that had not been possible to observe in previous experiments.