Effect of western corn rootworm larval mobility on predation by the soil mite Hypoaspis aculeifer

Corn rootworms are economic pests of maize throughout the Midwest. The majority of damage is caused by the larvae, which are subterranean and consume root tissue. Although immature life stages experience high levels of mortality under field conditions, little is known about factors that affect their susceptibility to natural enemies. In this study, we investigated how mobility of starved first instar western corn rootworm larvae (Chrysomelidae: Diabrotica virgifera virgifera) impacted predation by Hypoaspis aculeifer (Gamasida: Laelapidae), a soil-dwelling, generalist predatory mite. We conducted a series of lab experiments in microcosms. The first experiment explored differences in mobility between larvae from two age cohorts (2h and 24 h post hatch). We then investigated if mobility differences affected susceptibility of rootworms to predation by H. aculeifer females. Experiments are ongoing and we will discuss how results might impact existing rootworm management strategies.