Combat potato beetles: Naturally & organically

The pests can destroy entire potato harvests. We reveal which remedies help against the potato beetle and how to combat it naturally.

Potato beetles can become a real plague, and it is not for nothing that many parents and grandparents were sentenced to “collect potato beetles” as children in order to save the harvest. Therefore, it is important to recognize the pest early and to prevent it. If it is already too late for that, there are also various ways of combating it, ranging from home remedies and biological agents to chemical sprays.

Colorado potato beetle: origin and characteristics

The Colorado potato beetle (Leptinotarsa ​​decemlineata) is one of the leaf beetles and originally comes from North America. It was introduced to Europe at the end of the 19th century. Century and it was not long before the Colorado potato beetle became a pest. At that time there were no effective pesticides and so people had no choice but to collect the beetles from the potato fields. Only with the advent of modern pesticides could the Colorado potato beetle be combated effectively. However, the early pesticides were so toxic that the potatoes would probably never have made it onto the market today.

In order to combat the beetle as effectively as possible, it is helpful to understand its life cycle. In spring, when the first potatoes sprout, the Colorado potato beetle wakes up and leaves its winter quarters. After the beetles have left the soil, they begin to feed on the small potato shoots and lay their eggs on the underside of the potato leaves. Depending on the weather, the larvae hatch from the eggs after three to twelve days and begin to eat the plants much more than the adults. The larvae go through four developmental stages before developing into adult beetles.

In the first two larval stages, the larvae are very sensitive to plant protection measures and are not very hungry. However, once the third larval stage has been reached, the big feeding starts and biological insecticides are less effective. For this reason the larvae should always be controlled at an early stage of development. In dry weather, up to two generations of Colorado potato beetles are possible within a year. If the first generation is effectively controlled, the number of Colorado potato beetles in the following generations will be lower and almost negligible.

tip: An overview of more Potato Diseases and Pests can be found in our special article.

Recognizing Colorado potato beetles and larvae

Adult Colorado potato beetles are about one centimeter long and stand out because of their very characteristic appearance: they are yellow and have black longitudinal stripes on their backs. In addition to identifying the adult beetle, you should pay special attention to the larvae. The compact, red larvae are also easy to recognize by their black dots on the sides. If you have particularly good eyesight, you may also be able to spot the bright orange-yellow eggs on the underside of the leaf. The eggs are arranged in a round clutch.

The damage of the Colorado potato beetle

An infestation by the Colorado potato beetle is relatively easy to recognize. Already from the first sprouting of the potatoes, you have to expect signs of eating. Since the potato plant is despised by many pests because of its toxic ingredients, Colorado potato beetles are often the culprit if there are clear signs of feeding. To be more precise: the older larvae of the beetle are responsible for the eaten leaves. If there are enough larvae, they can eat a potato plant down to the thick veins of the leaves. This usually means a total loss of the harvest.

This is how you can tell if it is an infestation by Colorado potato beetles:

• Colorado potato beetles are about one centimeter in size and are strikingly yellow in color, with black vertical stripes on their backs
• Colorado potato beetle larvae are colored red and show black dots on the side
• Immediately after sprouting, signs of feeding can be seen on the leaves and shoot tips

tip: We recommend that you use a biological control agent as soon as the first signs of feeding by larvae appear. Our purely vegetable Plantura Organic Pest Free Neem is based on highly effective neem oil and ensures a quick stop to eating.

Prevent the potato beetle

Since the Colorado potato beetle comes out of the ground with the sprouting potatoes in spring, nets or the like are useless. Cultivation breaks only have an effect if no potatoes are grown in the entire garden for years, since Colorado potato beetles easily cover distances of up to 500 m in search of food. But there are definitely ways and means to reduce the probability of a threatening Colorado potato beetle infestation.

It is very effective to recognize the first potato beetle in the spring and to act quickly. We therefore recommend that you keep an eye out for the adult animals from the beginning of May. The first larvae can be expected in June.

The timing of potato cultivation can also prevent an infestation. If you push your potatoes underground, they will have a head start on the growth of the Colorado potato beetle. The Colorado potato beetle and its larvae cause less damage to the potato plants and you may be able to avoid combating them. In addition, and especially if you often have problems with Colorado potato beetles, it is worth using early-ripening potato varieties. Here, too, the common potato beetle can no longer exploit its full damage potential.

In addition, beneficial insects can reduce the number of Colorado potato beetles. So make sure you have plenty of retreat areas so that as many beneficial insects as possible “work” for you in your garden. Insects useful against Colorado potato beetles include, above all, predatory bedbugs and ground beetles.

Summary: How to prevent Colorado potato beetle infestation

• Observe cultivation breaks within a radius of 500 m
• Keep an eye out: from May onwards for fully grown Colorado potato beetles; from June for larvae
• Forcing potatoes to give your potatoes a head start in growth
• Precocious varieties help reduce yield loss
• Encourage beneficial insects such as predatory bugs and ground beetles

tip: With a blooming flower meadow you not only conjure up an eye-catcher in your garden or in a pot on the balcony, but also promote beneficial insects against the Colorado potato beetle. Our Plantura beneficial insect magnet is a seed mixture with more than 20 different plants that allows you to create such a beneficial insect paradise.

Fight potato beetles

When controlling the Colorado potato beetle, not only choosing the right agent, but also the time of control is of crucial importance. Since the adult Colorado potato beetle, in principle, does not cause any significant damage, combating it is of secondary importance. It's much more important Control of the first generation of larvae in spring. If this generation of larvae is effectively combated, a large population of Colorado potato beetles can no longer build up over the course of the year. Under normal conditions, you then have peace of mind from the Colorado potato beetle and can relax and wait for the potato harvest.

In the event of an infestation in spring, we recommend going straight to a biological agent. Neem oil-based supplements are a great way to use herbal methods to control Colorado potato beetles. Our Plantura organic pest-free neem is based on this valuable neem oil. The herbal remedy ensures a quick feeding stop and is not dangerous to bees. For use on the potato, simply 2.5 milliliters Plantura Organic Pest Free Neem mixed with 300-700 milliliters of water. About ten square meters of potatoes can then be treated with this emulsion. Since the active ingredient is absorbed by the plant, hidden insects are also reached. An important point: the larvae of the Colorado potato beetle are becoming more and more resistant to pesticides as they develop. It is therefore best to apply the pesticide shortly after the eggs hatch in spring. As with any crop protection product, correct application is important with organic pest-free neem in order to To achieve maximum treatment success, as well as to protect the environment and the user - always read the before use leaflet.

tip: Our Organic Pest Free Neem can also be used outdoors or indoors against other biting, leaf-mining or sucking insects such as aphids.

Combat potato beetles naturally with beneficial insects

At the present time there are no beneficial insects available that are able to fight the Colorado potato beetle really well. At this point we can only refer to the preventive measures. By encouraging naturally occurring enemies, such as ground beetles or predatory bugs, you reduce the likelihood of mass reproduction. In this way you can possibly avoid a plant protection measure with plant protection products.

Fight Colorado potato beetle biologically: home remedies and Co.

The oldest and at the same time most laborious method is collecting the Colorado potato beetle. For effective control, however, the larvae should also be collected and the eggs should also be crushed or wiped off. With individual potato plants on the balcony or terrace, this may not be a problem. However, if you are the proud owner of a larger potato patch, collecting them is an almost impossible task. It just takes a lot of time. If you do decide to use this remedy, we recommend collecting it in the morning. Other home remedies, which are often mentioned in connection with Colorado potato beetles, are almost ineffective. These means include:

• rock flour
• wood ash
• Sprays of fern or mint

A bacterial protein that acts selectively on the pest is available for biological control of the Colorado potato beetle in organic farming. This protein from the bacterium Bacillus thuringiensis ssp. tenebrionis but is not approved for private users. The protein available for the hobby gardener from Bacillus thuringiensis ssp. aizawai works well against caterpillars but not against the potato beetle. Our Plantura Zünslerfrei XenTari® contains this powerful protein and allows you to control free-feeding caterpillars on boxwood, cabbage and fruit trees.

Fight potato beetles with chemical agents

Pesticides are often harmful to beneficial insects and other insects in your garden. We therefore always recommend biological measures for the private garden. The Colorado potato beetle is against one of the most popular active ingredients in chemical control, the Pyrethroids, largely resistant, simply because this drug has been widely used in the past became. Most Colorado potato beetles are also resistant to the similar biological agent pyrethrum from the chrysanthemum. We strongly advise against controlling the Colorado potato beetle with these two active ingredients, as this will further promote resistance.

With these tips, nothing stands in the way of a successful potato harvest. By the way: Potatoes don't always have to be yellow. There is a colorful variety of potatoes, from which you can choose exciting varieties.