Wireworms, these fearsome underground beetles, are among the most damaging pests for agricultural crops. They attack roots and tubers, and can therefore seriously compromise plant health and crop yields. Let’s find out how to identify their damage and what control solutions to put in place to protect your crops.
Description of wireworm (Agriotes spp.)
Wireworms belong to the vast family Elateridae , which includes nearly 8,000 species worldwide, including around 200 in the genus Agriotes . In Europe, the species of Click beetle Agriotes obscurus , Agriotes sputator , Agriotes lineatus , and Agriotes sordidus are the most problematic and most commonly encountered on our crops.
These insects are nicknamed ” wireworms ” because of the rigid, cylindrical appearance of their larvae. They are also known for their amazing ability to produce a distinctive “click” sound when they turn around.
The larvae attack the roots of many plants, sometimes with devastating effects. Their preferred host plants include potatoes, lettuce, potatoes, carrots, beets, turnips, asparagus, tomatoes, onions and bulb plants.
Morphology of click beetle
- Eggs : Small (about 0.5 mm), the eggs are oval and usually laid deep in the soil, often in groups of ten.
- Larvae : “Wireworms” are distinguished by their straw-yellow color and rigid appearance, measuring between 2 and 25 mm depending on their age. Their head is brownish and flattened. They have 3 pairs of legs.
- Adults : These beetles vary from light brown to dark brown and measure between 6 and 12 mm. Mostly nocturnal, they move actively but rarely fly.
Development cycle of click beetle
The life cycle of wireworms can extend from two to five years depending on the species and environmental conditions. Long-lived species, such as Agriotes lineatus , Agriotes obscurus and Agriotes sputator , complete their development in five years, while Agriotes sordidus can complete its cycle in two to four years, influenced by soil temperature and moisture.
The laying
The cycle begins in spring, when adult females emerge after spending the winter in the soil. Between May and June, they lay between 100 and 200 eggs, buried a few centimeters deep in soils rich in organic matter.
The larvae
The eggs hatch and give birth to voracious larvae. Their development extends over several years during which they will pass through eight stages. Able to move vertically in the soil, they adjust their position according to humidity and temperature. In dry summer periods or during winter, they go dormant, slowing down their activity until conditions become favorable again.
Nymphosis
Once the larval stage is complete, usually after two to five years, the larvae begin their metamorphosis. This process, called pupation, takes place deep in the soil.
Adults
Adults emerge in the spring following pupation. After mating, they lay their eggs in the soil, then die after a few months of activity. Before the onset of winter, adults often become dormant in the soil, allowing them to survive until the next suitable period.
Optimal habitat and conditions
Wireworms thrive in moist, organically rich soils. These environments provide them with both food and protection for their life cycle. They prefer temperate climates where they prey on sensitive crops such as potatoes, beets and strawberries. They are most active during warm, humid periods in spring and late summer.
What damage does wireworm cause?
Wireworm larvae , known for their underground activity, attack the roots of plants. This behavior disrupts the ability of crops to absorb water and nutrients, leading to progressive wilting, sometimes followed by complete dieback. Root vegetables and tubers, such as carrots, potatoes or beets, are particularly vulnerable. The perforations created by the larvae make these crops unfit for consumption or sale.
In addition to this direct damage, the wounds inflicted by the larvae promote the entry of pathogens into the plants, exacerbating fungal and bacterial infections. This further accentuates the decline in crop quality and yield.
Although adults are less destructive than larvae, their consumption of the leaves of some wild or cultivated plants can cause minor damage.
Biological prevention and control
Wireworm management relies on appropriate cultural practices and the use of environmentally friendly biological methods. Here are the most effective approaches to limit their impact.
Cultivation methods
- Crop rotation : alternating plantings on the same plot helps reduce the presence of larvae by disrupting their development cycle. This limits their access to their favorite host plants.
- Soil maintenance : A balanced soil, maintained with moderate moisture and little organic debris, is less favorable to the development of wireworms. This type of management reduces their ability to establish themselves permanently.
- Improved pH : Wireworms prefer slightly acidic soils. By increasing the pH using SILIBOOST, it is possible to make the soil less attractive to these pests.
Agrobiotop biological methods
We manufacture and develop natural solutions that help combat wireworms on your crops. Do not hesitate to contact us for all the wireworm solutions presented below.
Physical barrier :
To improve the soil of your crops:
To trap the wireworm:
- FUNNEL trap  (To be buried in the ground)  Â
- AGRIOTES Sputator Pheromones  Â
