The field vole (Microtus arvalis) is a common rodent that can cause considerable damage to crops. Its underground tunnels and voracious appetite can affect plant growth, reducing yield and crop quality. Prevention is therefore essential to limit damage and ensure crop prosperity.
Understanding the Life Cycle of the Field Vole
The field vole reproduces very quickly, with a litter of 4 to 8 young every 21 days. Females can have up to 5 litters per year, allowing for exponential population growth. Favorable climatic conditions, such as a mild winter and a wet spring, promote significant population growth. Abundance of food and lack of natural predators can also exacerbate the problem.
Signs of Infestation
It is important to monitor your fields regularly to detect early signs of infestation. The most common signs include:
- Gnawing marks on plants. Voles gnaw on the roots, stems and leaves of plants, leaving characteristic marks.
- Presence of burrows at the entrance of the fields. Voles dig complex underground tunnels, often visible at the entrance of the fields.
- Black and cylindrical droppings in and near the tunnels. Vole droppings are easy to identify and can serve as an indicator of their presence.
- Significant defoliation of plants. Excessive defoliation may indicate a vole infestation, as they actively feed on the leaves.
Natural and Ecological Prevention Methods
Natural and ecological techniques can be implemented to prevent field vole infestations.
Habitat Management
Modifying the vole habitat can make them less likely to settle in your fields. Simple and effective methods exist:
- Create physical barriers. Fine mesh fences, concrete walls or dense hedges can prevent voles from entering the fields. A wire mesh fence 50 cm high buried 20 cm deep is generally effective.
- Promote biodiversity. Varied plantings and dense vegetation areas can attract natural predators, such as birds of prey and martens, which feed on voles. For example, planting diversified hedges with trees and shrubs can create a favorable habitat for these predators.
- Manage ground cover. Regular mowing and controlled grazing of fields can reduce dense areas where voles breed and hide. Avoid overly dense areas and piles of leaves. Regular mowing of field edges and uncultivated areas can also help reduce potential habitats.
Reduce Food Sources
By limiting access to food, you reduce the attractiveness of your fields for voles. Simple practices can be put in place:
- Correct storage of crops. Make sure your silos are sealed and that crops are stored correctly to prevent voles from accessing them. Adequate storage can prevent voles from feeding on crops and settling in silos.
- Weed control. Regular weeding can reduce food sources for voles. Mowing weeds around crops is also a way to discourage them. A clean and well-maintained field is less attractive to voles.
- Remove attractive areas. Remove piles of wood, compost heaps, waste accumulation areas, and other places that can serve as shelter or food sources for voles. Removing these areas eliminates potential sources of food and habitat.
More Interventionist Solutions
In case of significant infestation, more interventionist solutions may be necessary. It is important to use them with caution and to comply with local regulations.
Trapping
Trapping is an effective method to reduce vole populations. There are different types of traps, each with its advantages and disadvantages.
- Cages. These traps are effective but require regular checking to prevent animals from suffering. Cages should be placed in areas where voles are active, such as entry tunnels and frequently used passages. Natural baits such as carrots, apples or bread can be used to attract voles.
- Glue traps. These traps are simple to use but raise ethical questions about animal welfare. Glue traps should be used with caution and responsibly. They are usually used in areas where voles are more difficult to capture with other methods.
- Bait traps. These traps use palatable baits to attract voles. It is important to comply with regulations and precautions for use. Baits should be placed in strategic locations and renewed regularly to maintain their effectiveness.
Strategic trap placement is crucial. It is important to identify areas where voles are most active, such as entrance tunnels and frequently used passages. Choosing baits adapted to the dietary preferences of voles in your area is also important.
Repellents
Repellents can be used to deter voles from entering your fields. There are natural and chemical repellents, each with its own advantages and disadvantages.
- Natural products. Peppermint, lavender and eucalyptus essential oils can be used as natural repellents. They can be applied around crops or in vole tunnels. It is important to note that the effectiveness of essential oils may vary depending on the vole species and environmental conditions.
- Chemical products. Some chemicals are available on the market, but their effectiveness is variable and it is important to use them with caution to minimize risks to the environment. Chemicals can affect wildlife and flora, so it is important to consult a professional before using them.
- Ultrasonic methods. The effectiveness of ultrasonic methods is controversial. Some devices emit ultrasound that is supposed to repel voles, but their actual effectiveness is not always proven. Further studies are needed to determine the effectiveness of these methods.
Biological Control
Biological control involves using natural predators or parasites to control vole populations. This method is more environmentally friendly than chemical solutions, but it may require a significant initial investment.
- Introduction of natural predators. Owls, martens and weasels are natural predators of voles. Installing nesting boxes for these animals can attract them to your fields. The presence of these natural predators can help regulate vole populations.
- Use of specific parasites. Nematodes are parasites that attack voles. They can be applied to the soil to control populations. Nematodes are generally effective in moist soils and can help reduce vole populations without affecting other species.
It is important to note that introducing predators or parasites can have side effects on the ecosystem. It is therefore important to consult a professional to assess the risks and benefits of this solution. Careful planning and monitoring are essential to ensure the ecological balance of your environment.
Early Prevention: Monitoring and Anticipation
Regular monitoring of your fields is essential to detect early signs of infestation and implement a preventive action plan. Early action is often more effective and less costly than managing a major infestation. It is important to identify areas at risk, such as wetlands, field edges and dense areas, where voles are more likely to settle.
Once you have identified the areas at risk, you can implement specific preventive measures, such as creating physical barriers, reducing food sources or installing nesting boxes for natural predators. By acting quickly and effectively, you can minimize the damage caused by voles. A proactive approach can help prevent infestations and protect your crops.
It is also important to participate in population monitoring and alert programs, which allow you to share information on vole infestations and implement coordinated control measures. Collaboration between farmers and institutions can be very effective in preventing and managing vole infestations.