Wildlife Damage Management, Internet Center for


Date of this Version

March 1983


Published in Proceedings of the Seventh Eastern Pine and Meadow Vole Symposium, Harpers Ferry, WV, March 3-4, 1983, Ross E. Byers, editor. Copyright © 1983Steblein, Miller and Richmond.


Subsequent to the prohibition of endrin use in New York State, a variety of alternate rodenticides and methods of rodenticide application have been examined in an effort to develop effective control measures for the pine vole, Pitymys pinetorum. These studies indicate that the manner in which the rodenticides are applied substantially influences their effectiveness in controlling pine voles. Specifically, in our experience placing poisoned bait directly in the animal’s subsurface tunnel systems has proved to be the most effective means of vole control. However, this method of bait placement is both time consuming and expensive. An alternate more cost-effective method of applying rodenticides is that of broadcast application. However, broadcast applications of rodenticides have been inconsistent in their effects in controlling pine voles (Richmond et al. 1978). The equivocal results produced by this method may be related to the timing of its use on a seasonal basis. Traditionally, orchards have been treated in the fall after apple harvest, but prior to vegetation dieback when abundant food resources may influence bait acceptability (Steblein and Richmond 1982). Indeed, McAninch (1981) found that broadcast treatments were most effective in reducing vole population size when treatments were carried out after the senescence of ground vegetation in the fall. The influence of a spring broadcast prior to grass greenup on vole populations remains unexplored. Thus, in this study we examine the efficacy of two anticoagulants, Bromodiorone (Maki, Chemparl and Brodificoum (Volid, ICI Americas, Inc.), and a toxicant, zinc phosphide (ZP Rodent Bait, Bell Laboratories) when applied using broadcast techniques in early spring.