Acoustic detection of arthropod infestation of grape roots: Scouting for grape root borer (Lepidoptera: Sesiidae)

Abstract

The grape root borer, Vitacea polistiformis Harris, is the principal pest of grapes (Vitis spp. L.) in Florida where chlorpyrifos is 1 of the few chemicals registered for its control. However, chlorpyrifos is not an ideal treatment because it is highly toxic to birds, fish, aquatic invertebrates, and honeybees. Also, the recommended timing of application conflicts with harvest dates. There is an effective cultural control method, known as mounding, but this method is currently cost prohibitive for commercial production and is not widely used. If mounding could be applied only to infested plants, the cost of this method would be reduced considerably. This study evaluated the potential of acoustics for detecting the larvae in-situ. Human listeners assessed likelihood of arthropod infestation for each site based on live acoustic samples as they were being recorded. Computer software later constructed acoustic indicators from these recordings that were used for computer assessment of infestation likelihood. After recording, the roots of sampled vines were excavated to determine infestation levels. Infestation likelihood predictions of both human listeners and computer software largely reflected infestation condition of tested sites. Consequently, acoustic methods could be developed as tools for growers to employ mounding only at sites most likely to be infested, and thus enable more cost-effective use of this cultural control tactic.