If your freshly harvested potatoes have dark tunnels running through them, wireworms could be the culprit. What are these animals? How do you look? How do you get rid of them?

In a nutshell

  • Wireworm is the larva of the click beetle (Elateridae)
  • Common species: Click beetle (Agriotes lineatus), Yellow-brown click beetle (Agriotes sputator)
  • dreaded pests in potato and vegetable cultivation
  • appear more frequently in spring
  • adult click beetles harmless

detect wireworm

Typical characteristics of the wireworm are:

  • two to three inches long
  • yellow to orange-brown body colour
  • dark brown head
Larva of the click beetle
Source: Danny Steaven, Agriotes-lineatus-011, Edited by Plantopedia, CC BY-SA 3.0

A so-called potato trap helps to make wireworms visible on a bed. This is how you build it yourself:

  1. Cut some potatoes into thick slices.
  2. Push the potato slices into the soil about five centimeters deep.
  3. Already the day after next you can see whether the potato slices have dark tunnels or are free of the voracious larvae.

Notice: If you find a wireworm infestation, move the potato patch to a different spot.

Control wireworms biologically

Various means are available to you for the natural control of the click beetle larvae. We have listed the most promising ones below.

potato trap

The potato trap not only helps with identification, it is also a suitable means of biologically combating the pests. It is not only used on potato cultivation areas, but on all vegetable beds. Simply proceed as described above and then regularly collect the potato slices and click beetle larvae.

You can also stick several potato slices into the ground on a wooden skewer. This makes it easier to collect later.

Tip: The potatoes stuffed with wireworms make a feast for the birds in your garden. Lay out the discs so that they are clearly visible to the birds.

dig up earth

Digging up an area helps get rid of click beetle larvae. Proceed according to the following instructions:

  1. Dig the bed on a dry, sunny day.
  2. This is how the wireworms reach the surface. There you can easily recognize and collect them.
  3. Since the pests are on the menu for many animals, place them where they are clearly visible to predators such as hedgehogs, frogs or birds.

use nematodes

Nematodes are important helpers in the biological control of various types of pests. This is how the small threadworms help against wireworms:

  • to buy in specialist shops
  • according to the instructions for use in irrigation water
  • water affected areas with it
  • get into the ground
  • penetrate wireworms
  • lay eggs in their bodies
  • The result is the death of the pests within a few days
  • Repeat application until no more wireworms are visible

Notice: Click beetle larvae also get into flower pots via the potting soil and wreak havoc there. Watering with nematodes also quickly leads to success here.

Natural garden design

Click beetle larvae have no chance of surviving in gardens where hedgehogs, birds and many beneficial creatures feel at home. They are eaten faster than they can do any damage.

Intelligent mixed culture

For decades, vegetable farmers have been looking for suitable solutions to combat wireworm without chemicals. One way to drive away the pests in the long term is mixed cultivation. For example, marigolds or marigolds (Calendula officinalis) are good pest repellents. Plant some of the bright orange flowers between the vegetable patches.

Marigolds (Calendula officinalis) contain toxins that wireworms eat.

prefer plants

The stronger the potato and vegetable plants are, the less they are threatened by pests. Pulling them forward on the windowsill increases the plants' stability and resilience.

Notice: Lawns are particularly at risk for wireworm infestation. If you are planning to transform a lawn into a vegetable patch, remove the sod thoroughly. Dig up the area well and leave it fallow for two years if possible. Check the area regularly for larvae.

frequently asked Questions

What soil quality do wireworms prefer?

Grassy areas and freshly turned soil are very attractive to click beetle larvae. We recommend not planting vegetables in the bed immediately after digging. The pests also like moisture very much. For this reason, the loosened soil should dry well before planting begins. If possible, you should not leave beds intended for growing vegetables until a year after digging them up. Lime fertilizers help to drive away the wireworm.

How to identify click beetle eggs?

From June to July, female click beetles lay up to 250 eggs in small packages of about 20 pieces two centimeters deep in the ground. The larvae hatch after five to six weeks. They need three to four years to develop.

Where do click beetle larvae overwinter?

The robust pests spend the cold season well-protected at a depth of about 60 centimeters in the ground.

Category:

Garden pests