Efficacy of methyl nonyl ketone as an in‐soil repellent for common voles (Microtus arvalis)

Abstract

Common voles (Microtus arvalis) can cause enormous damage in agriculture. Tests were conducted using an alternative approach to rodenticide-based vole management by developing an in-soil odour repellent based on the secondary plant metabolite methyl nonyl ketone (MNK). Replicated 25 m(2) plots were established in forage grassland to test efficacy and application schemes using a foam application that included MNK. MNK significantly reduced the number of reopened burrow entrances in all field trials compared with untreated control plots, with repeated application for 6 days reducing vole activity by up to 90%. The addition of black pepper oil (BPO) did not enhance the efficacy of the MNK foam. Voles tended to avoid burrows where MNK was applied and rather opened new burrows instead of reopening the treated burrow entrances. The foam application scheme led to a repellent effect that lasted for about 4-5 days. A single additional application of MNK after 4 days can extend the treatment effects for a further 2 days. The results indicate that MNK has the potential to repel common voles in the field. However, more studies are needed to enhance the duration of a one-off treatment effect to yield a user-friendly field application to manage vole populations.