Testing an integrated approach for managing roof rats in citrus orchards.

Background: Roof rats (Rattus rattus) are a substantial pest throughout citrus crops, yet little is known about efficacious, cost-effective strategies to manage this rodent. Therefore, we developed two integrated pest management (IPM) programs that incorporated elevated bait stations containing diphacinone-treated oats and trapping, and we compared those programs to a bait-station only approach to determine which strategies were most practical for the management of roof rats in citrus orchards.

Results: Bait applications substantially reduced rat activity within orchards. However, our initial IPM approach that used a combination of baiting, snap trapping and Goodnature® A24 traps were not successful at keeping rats from rapidly repopulating. A second IPM strategy that relied on baiting and more extensive snap trapping was effective at reducing rat activity up to, and likely beyond, a 6-month treatment period. Although baiting by itself was less expensive than IPM plots, the difference in cost between baiting and the IPM approach that used only baiting and snap trapping should be minimal during long-term management programs.

Conclusion: The high efficacy of a management program that incorporates an initial bait application, followed by a long-term snap-trapping program, should yield effective management of roof rats in citrus orchards. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.