Vole Damage
Identification
Meadow vole (field mouse) Microtus pennsylvanicus
Body 90-130mm long; dark chestnut brown with greyish belly. Ears smaller and tail shorter (35-65mm) than that of mice
Pine vole, Pitymys pinetorum
Body 70-110mm long; auburn brown fur, very thick and soft. Tail shorter than meadow voles at 17-25mm
Vole injury to grape vines consists mostly of girdling of trunk and canes and sometimes root pruning. It has been reported in vineyards in the Georgian Bay area.
Management Notes
Meadow voles usually feed on grass seeds, herbs and bulbs during the spring and summer then shift to bark in the fall and winter. They make shallow runways along the soil surface whereas the pine vole burrows deep and feeds underground mainly on rootlets and the bark stripped from larger roots.
A wide herbicide strip beneath the vines coupled with regular close mowing of row middles helps to discourage rodents. The abundance of nesting material and places to hide offered by brush and trash should be avoided. Remove straw, trash, sod, etc. from around the base of the vine for at least 60 cm from the trunk. Fall hilling with soil may also help.
For maximum protection in areas where vole injury is a problem, all newly planted vines should have a wire or plastic guard with small aeration holes placed around the trunk. The bottom of the guard should be buried in the soil 5 cm deep, or better yet, in a mound of fine crushed stone or sharp cinders. All tree guards should be checked each fall to see that they are rodent tight, free of trash, and are not interfering with root development.
A number of commercial tree guards are available. Two of the most common are spiral plastic and galvanized wire mesh. Orchard grower experience has shown that a guard approximately 45 cm high is adequate. This may be a challenge where multiple trunks are present.
If you are making your own guards, do not use dark coloured materials or tar paper. These materials can increase the temperature of the bark on sunny days in winter and subsequent low temperatures at night can cause injury to the bark tissue. Also, they provide a place for trunk damaging insects to live. Heavy aluminum foil or thin metal sheets should also be avoided. Unventilated guards of this type have the potential to damage vines by allowing the trunk to heat.
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