Last week’s column addressed pests that leave mysterious holes in the landscape, giving particular attention to moles. Voles, like moles, are active day and night all year. The two pests are often confused, but identification is important when controlling them.
Of North Carolina’s two kinds, the pine vole is common in the Lenoir County area. Voles can seriously damage trees, shrubs, perennials and bulbs because they forage under the ground and out of sight. Mostly herbivorous, they feed on a variety of grasses, herbaceous plants, bulbs and tubers.
Their garden plant diet includes artichoke, beets, Brussels sprouts, cabbage, carrots, cauliflower, lettuce, spinach, sweet potato, tomato and turnip. They eat bark and roots of trees, usually in fall or winter.
The pests normally damage tree trunks a few inches above or below ground. If below, remove soil from the base of the tree to see the damage. Voles are poor climbers but can reach low-hanging branches and cause damage higher up on trees.
Voles dig many tunnels and surface runways with numerous burrow entrances. They store seeds and other plant matter in underground galleries. While rarely seen above ground, their tunnel system makes the soil soft and spongy under foot. Moles are often blamed for this damage because voles will use mole tunnels to reach plant roots and bulbs.
The vole population regularly fluctuates from year to year. The pests are prolific, with peak breeding period in the spring. An occasional population cycle increase can spike numbers to several thousand per acre.
Voles raise their young in underground nests of grass, stems and leaves. Several adults and young can occupy a burrow system. Voles seldom live longer than 12 months.
To prevent vole damage, try to manage the population before it reaches high numbers. The apple sign test will reveal locations of activity, and traps or rodenticides should be used only in those areas.
Place a creased shingle or flowerpot that is weighed down over a vole hole. After a few days, place a piece of apple under the shingle or pot. Check the site 24 hours later to see if the apple has been removed or eaten.
A snap-type mousetrap can catch voles, baited with a piece of apple or peanut butter. Place in the vole run or under the cover of a flowerpot or creased shingle. Arch the shingle crease so the strap will spring clear of the shingle.
Voles seldom stray from their runways, so it is crucial to set traps along these routes. Place at right angles to the runways with the trigger end in the runway. Examine daily, removing dead voles or resetting sprung traps.
Continue to trap in one location until you stop catching voles, then move to a new location 15 to 20 feet away. Destroy old runways or burrows to deter new voles from moving in.
When voles are numerous or when damage occurs over large areas, toxic baits can be the quickest and most practical means of controlling these major infestations. Be sure to protect the safety of children, pets and non-target animals.
Use a warfarin product called Kaput, labeled for homeowners, and carefully follow label instructions. Every 10 feet throughout the infested area, establish covered bait stations. After 21 days, repeat the baiting. In another 21 days, conduct the apple sign test to confirm control.
A barrier of wire fencing, sharp gravel or heavy plastic can block voles from plantings. Bury the bottom edge 10 to 12 inches deep so voles can’t tunnel under it. Surround the trunk with these cylinders, being sure not to press against the trunk and to allow room for tree growth.
Voles and moles have their place in nature and are limited by natural constraints. In the home landscape, populations often exceed tolerable limits.
Trudy W. Pickett is extension family and consumer agent at the Lenoir County Cooperative Extension Office, 1791 N.C. 11/55. Reach her at 252-527-2191 or trudy_pickett@ncsu.edu.