Proceedings of the Vertebrate Pest Conference

Methods of controlling meadow mice of various species are reviewed: Microtus californicus in the West, M. pennsylvanicus in the East, M. ochrogaster in the Midwest, and Pitymys spp. in the East and South. Control methods employed have included habitat modification, use of individual guards or repellents around tree trunks in orchards, and burrow fumigation against Pitymys spp. and M. ochrogaster. Trapping is generally practical only on a small scale, using wooden-based snap traps baited with pieces of apple and/or rolled oats, or using pit traps. Rodenticides generally have provided the best control of meadow mice. While strychnine is still used by some orchardists, zinc phosphide had been shown to be more effective and presents less nontarget hazard. The practice of trail baiting was developed and is discussed, either by hand or by use of mechanical bait dispensers such as the trail-builder. Ground sprays were developed by the early 1950s, and endrin was found to be the most effective toxicant against pine mice (Pitymys spp.), however at times it has given poor results in some Midwestern states. This method is not recommended by the Bureau, due to potential nontarget hazards as well as environmental concerns about continued used of chlorinated hydrocarbons. Currently, broadcast zinc phosphide rodenticide applications in orchards provide the most economical control solution and are considerably less hazardous to non-target species. A list of relevant publications is provided.