Wireworms are pests that can cause significant damage to garden crops and can be difficult to control. They are the larvae of click beetles and feed on the roots and underground parts of plants. This can result in stunted growth, wilting, and eventual death of the plant.
Symptoms
- Wilting or yellowing of leaves
- Stunted plant growth
- Dying or failing to thrive plants
- Small holes or gnaw marks on roots and underground stems
- Presence of adult click beetles
- Poor root development
- Stunted or missing root systems
- Plant death or wilting in areas of the garden or field.
What is a Wireworm
- Elongated, cylindrical shape
- Hard, shiny, and smooth exoskeleton
- Length ranges from 1/2 inch to 2 inches
- Color ranges from light yellow to brown with darker segments
- Worm-like, segmented appearance
- Three pairs of legs near head
- Tapered at both ends.
Treating a Wireworm Infestation
In some cases, a combination of chemical, physical, and biological control methods may be necessary to effectively manage a wireworm infestation.
Cultural Control
- Crop rotation: Planting crops in different areas of the garden each year can reduce the population of wireworms as they are not able to continually feed on the same crop. Crop rotation can be done on a 3-4 year cycle, ensuring that wireworms are not able to feed on the same crop in the same location for several years in a row.
- Sanitation: Clearing garden beds of plant debris and removing infested plants can reduce wireworm habitats and food sources. Removing crop residue, such as leaves and stalks, and practicing good garden hygiene can help reduce wireworm populations.
- Mulching: Adding a layer of organic mulch can discourage wireworms from reaching the soil and plants. A mulch layer of at least 2-3 inches deep can prevent wireworms from accessing plant roots.
- Resistant crops: Choosing crops that are less attractive to wireworms, such as onions and garlic, can reduce the severity of infestations.
Chemical Control
- Soil treatments: Using insecticides specifically labeled for wireworms applied to the soil can reduce wireworm populations. Some common insecticides used to control wireworms include carbaryl, chlorpyrifos, and imidacloprid. It is important to follow label instructions and safety precautions when using chemical insecticides.
- Seed treatments: Treating seed with insecticides before planting can reduce wireworm damage. Some seed treatments include neonicotinoids and insect growth regulators, which can provide season-long protection against wireworms.
- Baits: Placing poisoned baits in the garden can attract and kill wireworms. Baits, such as slices of potatoes or carrots treated with insecticide, can be placed in the soil and monitored for wireworm activity.
- Chemical barriers: Creating a chemical barrier in the soil with insecticides can prevent wireworms from reaching plant roots. A shallow trench can be dug around the perimeter of a garden bed and filled with insecticide to create a barrier.
Physical Control
- Hand picking: Removing wireworms from soil by hand can reduce their populations. Monitoring garden beds for wireworms and removing them by hand can be an effective control method, especially in smaller gardens.
- Tillage: Deep tillage in the garden before planting can disrupt wireworm populations. Cultivating the soil to a depth of 8-12 inches can expose wireworms to predators and reduce their populations.
Biological Control
- Beneficial nematodes: Introducing beneficial nematodes, microscopic worms that feed on wireworms, into the soil can reduce wireworm populations. Nematodes can be applied to the soil in the form of a suspension, which can be watered into the soil.
- Natural predators: Encouraging populations of natural predators of wireworms, such as birds and ground beetles, can help control infestations. Maintaining a diverse garden ecosystem with a variety of plants and habitats can attract natural predators and reduce wireworm populations.