Western Corn Rootworm, Plant and Microbe Interactions: A Review and Prospects for New Management Tools

Abstract

The western corn rootworm, Diabrotica virgifera virgifera LeConte, is resistant to four separate classes of traditional insecticides, all Bacillius thuringiensis (Bt) toxins currently registered for commercial use, crop rotation, innate plant resistance factors, and even double-stranded RNA (dsRNA) targeting essential genes via environmental RNA interference (RNAi), which has not been sold commercially to date. Clearly, additional tools are needed as management options. In this review, we discuss the state-of-the-art knowledge about biotic factors influencing herbivore success, including host location and recognition, plant defensive traits, plant-microbe interactions, and herbivore-pathogens/predator interactions. We then translate this knowledge into potential new management tools and improved biological control.

Keywords: Western corn rootworm; belowground herbivory; biological control; pest management strategies; plant defenses; push-pull; soil health.

Figure 1

Broadening of management tactics aimed at controlling western corn rootworm (Diabrotica virgifera virgifera LeConte) and reducing damage to maize. The inner most circle (light green) represents the most common and widely adopted management techniques, all of which have seen failures in the field due to evolved resistance by western corn rootworm. The middle circle (dark green) represents management techniques less frequently adopted but have demonstrated effectiveness in laboratory or small field trials. The outermost circle (orange) represents management tactics that show promise and could be adopted using existing technology. Orbiting circles (blue) represent future management tactics that could be used if developed further.