Potato beetles may look inconspicuous, but they can cause enormous damage. We will show you some effective measures to get rid of the pests again.
Once the potato beetle has found its way into the vegetable garden, the potato harvest is in acute danger. The small and harmless-looking beetles can destroy entire potato plants within a short time. The beetles multiply rapidly. A mass infestation is difficult to combat. If you regularly check your potato plants and specifically combat eggs, larvae and beetles, you will be able to save your harvest.
In the following you will find out how you can recognize the Colorado potato beetle and how you can fight it with natural means.
Detect potato beetle
The Colorado potato beetle (Leptinotarsa decemlineata) belongs to the leaf beetle family. Its original home is in Colorado. The term "colorado beetle" is common there. In order to effectively counter an infestation, eggs, larvae and beetles must be identified with certainty.
Eggs Of Colorado potato beetle - © Andrei310 / Stock.adobe.com
Features: • colored bright orange • like a cylinder shaped • placement in clusters • occurrence on the underside of the leaf
Larvae of Colorado potato beetle - © Dmitriydanilov62 / Stock.adobe.com
Characteristics: • young larvae reddish brown • older larvae are yellow • black dots on head and sides • occur on top and underside of leaves
Potato beetle - © Nechaevkon / Stock.adobe.com
Characteristics: • up to 15 millimeters in size • yellow colouring • Wings have five black vertical stripes • Pronotum mottled orange and black • Underside reddish brown, black dots on the sides
Malicious image of the potato beetle
When the Colorado potato beetle begins its destructive work, no one more attentive can do itoverlook vegetable gardeners. The potato leaves serve as a food source for both the mature larvae and the beetles.
First of all, holes in the middle of the sheet or indentations on the edges of the sheet catch the eye. If you don't intervene promptly, usually only the thicker leaf veins remain. Severe infestations even result in defoliation. Only the stems and a few thicker side shoots are spared.
Tip: The Colorado potato beetle doesn't just settle on the potato plant. Other nightshades such as tomatoes, peppers and aubergines are also at risk.
Do we really have to fight Colorado potato beetles?
When the Colorado potato beetle was introduced to Germany at the end of the 19th century, it didn't take long before entire potato fields fell victim to it, threatening the survival of entire families.
If the beetles are not fought, they will become a real plague and the vegetable gardener will have to forego his harvest. Therefore, there is no way around fighting the voracious beetles and their brood.
Warning: The Colorado beetle can develop resistance to insecticides and should be controlled with natural means.
Fight potato beetle naturally - the best methods
Collect Potato Beetle
If the infestation is lighter and the potato patch is manageable, collecting the animals proves to be an effective method. You should allow some time and must be careful not to miss any eggs, larvae or bugs.
Tip: Also pay attention to the underside of the leaves. There are the eggs and also numerous larvae.
The best time to collect is early in the morning. The beetles and larvae are then even more immobile and can be removed more easily. You should use a container with a lid for collecting. Otherwise the bugs will fly away quickly. It will be necessary to check the plants several times.
The bugs can be left in the jar until they die on their own. Dousing with water also leads to death. If this seems too brutal to you, you can release the collected Colorado potato beetle into the wild on a walk in nature. Your own potato patch should be at an appropriate distance.
Fight potato beetle with rock flour
As the name suggests, it is particularly finely crushed rock. Ground stones contain silica and nutrients and are commonly used as fertilizerused.
Infested potato plants are pollinated with rock flour. This creates a film on the leaves, which deprives the Colorado beetles of their food source. The flour also causes the beetles to lose body fluids and dry out.
It is best to apply the rock flour in the early morning hours. Because of the dew, the fine flour sticks better to the leaves of the potato plant. The vertical position of the leaves in the morning is also an advantage. The rock flour also gets on the underside of the leaves, where the eggs are laid.
Tip: Dried coffee grounds have a similar effect to the rock powder described.
Fighting the potato beetle with vegetable decoction
Fern or mint against potato beetle
To make this herbal decoction, fill an ordinary water bucket halfway with fern fronds or mint leaves. The coarsely chopped plant parts are poured over with five liters of water. The broth is boiled for about half an hour. The cooled broth is strained and diluted with water in a ratio of 1:10.
Spray the vegetable decoction onto the potato plant in the morning and evening and don't forget to treat the underside of the leaves as well.
Horseradish against potato beetle
Horseradish has proven itself as a natural pesticide against Colorado potato beetles.
Application step by step:
-
- Use 400 grams of fresh or dried horseradish
- Pour 20 liters of water over the horseradish
- Expose the mixture to the sun for a few days
- Pour the solution into a spray bottle
- Spray the potato plant thoroughly
Tip: You can also use horseradish stock as a preventive measure. If you put the liquid manure on the potato patch in spring, the potato beetle will be deterred and move on to lay their eggs.
Fight potato beetle with bacteria
The bacterium Bacillus thuringiensis comes into consideration here. After spraying on the plants, a toxin is released which can kill beetles and larvae. The substance is harmless to humans and animals, and the bacterium cannot harm other plants either.
After ingesting the bacillus, beetles and larvae stop eating and eventually die. The commercially approved products are already effective against young larvae. Therefore, you should treat the potato plants with the Bacillus at an early stage.
The infestation withPrevent potato beetles
Adequate preventive measures can prevent or reduce an infestation.
Mixed cultivation prevents potato beetles
If you opt for a mixed culture, there is a high probability that the pests will ignore the potato plants. The ideal plant neighbors have a positive effect on the development of the potato plants. Resistant plants are less likely to be attacked by the pests.
Potatoes develop very well in the vicinity of:
- Peas
- Spinach
- Mint
- Caraway
Tip: Colorado potato beetles retreat into the ground to hibernate. It is therefore advisable to look for a different location to plant the potatoes every year.
Potato beetles cannot harm new potatoes
The Colorado potato beetle becomes active in early summer. Egg laying begins in June. If you grow early potatoes, you can outsmart the Colorado potato beetle and harvest your potatoes before the first beetles hatch.
The following potato varieties are already ready for harvest in July:
- Christa
- Astoria
- Sieglinde
- Agata
- Hela
- karat
Keep away potato beetles with pest protection nets
You can protect your potato plants from pests by installing pest protection nets. This affects not only the Colorado potato beetle, but also maggots and caterpillars. At the same time, reliable sun protection is ensured and less watering is required.