Using biological pest management is one of the safest and most sustainable ways to protect crops. In this guide, you will find tips and techniques for using biocontrol and biopesticide products specifically for potato crops.
- Potato crops and biological control
- Why use biocontrol on potatoes?
- How to diagnose potato pest problems
- What are the main pests and diseases of potatoes
- Top biocontrol solutions for potato pests
- How to apply biocontrol effectively
- Integrating biocontrol in IPM plans
Potato crops and biological control
Biological control involves the use of biocontrol and biopesticide products, which are based on natural enemies of pests and nature-based materials, to prevent and treat problems on your crops. These non-toxic solutions offer targeted, cost-effective and robust options to keep your potato crops healthy and thriving.
To learn the basics of biocontrol and biopesticides, read Biological pest control: A beginner’s guide
Why use natural biocontrol on your potato crop?
Current farming practices are putting increasing pressure on potato ecosystems, including local biodiversity (and the benefits it provides), soil health, and the health of people working and living on the farms.
Benefits of bioprotection products over synthetic chemical inputs
Using bioprotection products is a sustainable and safe option to keep potato crops healthy whilst protecting the surrounding ecosystem. They support long-term soil health and reduce exposure of people and wildlife to harmful chemical residues. They also help reduce the onset of pesticide resistance by pests.
Using biological products can help you comply with sustainability and organic certification schemes, which can enable you to sell your produce to broader markets.
Environmental and soil health advantages
Bioprotection products are usually safer for beneficial insects, soil organisms, and surrounding biodiversity. By protecting soil structure and its microbial life, biocontrol supports long-term soil fertility and crop resilience.
Preventing resistance with biocontrol
Bioprotection products use multiple and often complex modes of action, making it harder for pests to adapt. This helps prevent the buildup of resistance and keeps these products effective over time.
How to diagnose potato crop pest pathogens
Firstly, to effectively use biocontrol on your potato crop you need to identify the pest or disease you are dealing with. Accurate diagnosis helps choose the right control product or strategy, avoiding crop losses.
Early signs on leaves and tubers
Early detection is key. Regularly inspect your crop and look for signs of damage or infection. For instance:
- Leaves: Yellowing, wilting or curling may indicate either pest damage or disease symptoms. Holes and mines often point to chewing insects.
- Stems: Black stems, rot, or collapse of the plant could signal bacterial or fungal infections like blackleg or bacterial wilt, as well as nematodes.
- Tubers: Cracked, discoloured, or rotting tubers may be caused by wireworms, nematodes, or soil-borne pathogens. Tunnels or lesions can be caused by larvae of insects.
- Soil and roots: Check for larvae, wireworms, or swellings on roots caused by nematodes. Root damage often goes unnoticed until symptoms appear above ground.
How to distinguish insect pests from diseases
Insect pests, nematodes and diseases can cause similar symptoms like wilting, yellowing, or stunted growth. However, some patterns are distinctive. For example, insect pests often leave visible traces such as frass (debris or excrement), holes/mining patterns in leaves, or tunnels in tubers. Diseases usually cause lesions, mould, wilting and/or yellowing of the plant. Nematodes sometimes cause odd-shaped swollen areas (galls) on roots.
When to act: thresholds and timing
Most bioprotection products work best when applied before pest populations reach damaging levels. Monitor pest populations regularly using traps or scouting methods and define an action threshold: the point at which measures should be taken to control the pest.
When using a bioprotectant, the timing of the application is also important to ensure that the pest is targeted at its most vulnerable stage. This also prevents the bioprotection product from losing its efficacy. Environmental conditions can also significantly influence efficacy and field persistence, e.g. intense sunlight can damage some bioprotectants.
Resources to help with diagnosis
If you’re not sure what pests or disease you have on your potato crop, here are a few resources that can help:
- The CABI pest and disease photoguide to potato disorders (in English only)
- A platform for potato diseases produced in South America (in Spanish).
- The PlantwisePlus Knowledge Bank for further information on pest and diseases diagnostics
- COLEAD’s Guide to good plant protection practices for the production of potato in ACP countries (in French or English)
What are the main pests and diseases of potatoes?
One particularly problematic disorder present in potatoes is late blight (Phytophthora infestans). The disease is one of the most destructive and widespread to affect potatoes. Thankfully, bioprotection products can be used to help prevent and manage late blight.
- Learn more about late blight and biocontrol with our in-depth guide
Potato plants are attacked by a variety of other pests and diseases, including insects and microorganisms like bacteria, fungi, and viruses. Below are some of the most significant ones.
Colorado potato beetle (Leptinotarsa decemlineata)
This beetle feeds on many plants, including potatoes. Adults are about 9.5 mm long and have black and cream stripes running along their backs. They feed directly on plant leaves, with most damage caused during their early developmental stages (instars). Large infestations can lead to significant leaf loss, slowing plant growth and reducing yield, which can seriously impact overall plant health and productivity.
Potato tuber moth (Phthorimaea operculella)
Similar to other moth pests, the larval stage of the potato tuber moth is the one that causes damage to potato plants. Early-stage larvae are white or light brown with a brown head, while older larvae are pink or pale green/grey. The adult moths are about 1 cm in length and pale brown in colour, with darker marbling.
Larvae feed on tubers, leaves, and stems and can even multiply during storage of tubers. Symptoms include leaf mines and weak or broken stems. Detection on tubers usually requires cutting them open, which shows the presence of galleries and larvae.
Aphids
Aphids are small, soft-bodied insects that damage many plants, including potatoes. They are usually green, black, or grey and damage potatoes by sucking sap from leaves and stems; they also spread potato diseases, such as Potato Virus Y and Potato leafroll virus.
Two of the most common aphid pests on potato are the Green peach aphid (Myzus persicae) and the Potato aphid (Macrosiphum euphorbiae). If aphid numbers are high enough, their feeding can cause leaf wilting and reduced yield. However, spreading plant viruses is the biggest problem.
Parasitic nematodes
Plant parasitic nematodes are tiny worm-like organisms that live in the soil and, sometimes, within the root system of a plant. Several species can damage potatoes. This is the case of the potato cyst nematode (Globodera spp.) and the root-knot nematode (Meloidogyne spp.).
Root-knot nematodes cause characteristic swellings on roots, known as galls, while potato cyst nematodes cause lemon-shaped cysts. In heavy infestation, the tubers can develop galls or cysts. Above ground, the damage resembles other types of root problems, with symptoms such as leaf yellowing and wilting that usually develop from the ground upwards.
Leaf miners (Liriomyza spp.)
Several species of leaf miners attack potato, but the most significant is the potato leaf miner (Liriomyza huidobrensis). These are small flies, about 2mm in length. The potato leaf miner is recognizable for its grey/black body with a yellow spot on top. Larvae feed on the leaves, creating a ‘mining’ pattern, usually restricted by the leaf veins. Damage from mining can cause premature leaf drop and can be an entry point for bacterial and fungal diseases.
Bacterial wilt (Ralstonia solanacearum)
Bacterial wilt of potato is caused by the soil bacterium Ralstonia solanacearum that infects through the root system. Symptoms of an infection include sudden wilting, sometimes followed by yellowing and die-back of plants. The inside of the stem is usually dark and watery. In tubers, brownish-grey areas are visible on the outside and droplets of bacterial slime ooze from the eyes.
Potato blackleg disease (Pectobacterium atrosepticum)
This disease is caused by the bacterium Pectobacterium atrosepticum which results in black rotting at the stem’s base. Early symptoms include stunted growth and yellowing of leaves that go on to curl and become stiff. Later in the infection, the stem completely rots and dies. Infected plants produce few or no tubers, with those tubers that remain showing discolouration and rot. Blackleg disease can also cause seed decay, preventing plant emergence.
Flea beetle (Epitrix spp.)
Several species of flea beetle attack potato, including the potato flea beetle (Epitrix cucumeris) and the tuber flea beetle (Epitrix tuberis). Early stage flea beetle larvae are white/cream in colour, older larvae are slender, 5mm long with a brown head. Adults are brown to black beetles, 1.5-2mm long and usually jump like fleas.
Both flea beetle larvae and adults feed on potato plants. Typically, adults feed on leaves, creating small round holes, while larvae feed on roots and tubers, causing tiny tunnels on the surface, or inside. Tunnels on the surface of tubers can lead to scar formation.
Wireworms
Wireworms (representing various genera) are the larval stage of click beetles. These larvae are slender, typically yellow to brown in colour, and feed on underground plant parts, including tubers. Their feeding causes lesions and tunnels in tubers, significantly decreasing yield. Aboveground signs of wireworm presence/feeding include wilting and stunted growth.
White grubs
White grubs are the larvae of different scarab and chafer beetle species. They live in the top layer of soil and feed on many crops, including potatoes. The larvae are creamy-white with red/brown heads and are normally found in a typical “C” shape. They eat potato roots, stems, but most importantly, tubers, making them unmarketable.
Top biocontrol solutions for potato pests
Finding the right biocontrol or biopesticide
Once you have identified the problem, you can select the most appropriate biopesticide or biocontrol method to use.
Selecting the most suitable control product is an important part of ensuring a biocontrol approach will be effective. For example, some biological products have certain environmental requirements when applied in the field; some only work on restricted pests or crops, and some may be more appropriate when used on a smaller scale.
To choose a biocontrol product or method, you need to ask the right questions.
Our Selecting the right biopesticide or biocontrol product for your needs takes you through the steps to make the right choice.
Some of the key steps to selecting a biological potato crop management method include:
- knowing what biocontrol and biopesticide products are permitted and available in your country, on potato and for your particular pest or disease
- deciding if other management practices you use, particularly chemical inputs, are compatible with the biological products
Use the CABI BioProtection Portal to review biocontrol and biopesticide products
Macrobials (predators, parasitic wasps, nematodes) options
Macrobial products can be used to manage certain pests on potatoes. An example is the entomopathogenic nematodes (or EPNs). EPNs (including species such as Steinernema carpocapsae and S. feltiae) are microscopic worms in the soil. They can be used to control various potato pests, including white grubs, cutworms and leaf miners. The nematodes can do this by seeking out the pest and then infecting it, eventually causing the death of the pest.
Biopesticides: neem, Bt, Trichoderma, etc.
One popular biological that has been used successfully on a wide variety of crops including potato, particularly for disease control, is the fungus Trichoderma. The fungus can be used in potato in many different ways, including being added to the soil in potato nurseries or direct to field. Using Trichoderma in this way can:
- directly kill plant pathogens
- improve plant growth
- stimulate plant defence mechanisms
- allow better absorption of nutrients
The bacterium Bacillus thuringiensis, also known as Bt, is another popular microbial biopesticide for potato pest management. It can be used against larvae of insect pests like the Colorado potato beetle or the potato tuber moth.
Aside from biocontrol products containing living organisms, there are other non-living biocontrol products based on natural substances that can provide effective and safe control of potato pests. These are often based on plant extracts or botanical oils and can directly kill the pest or produce a repellent or anti-feeding effect. Azadiracthin is an example of a natural substance now available as a biopesticide for controlling potato pests. This active ingredient is from the Neem tree and can be used to control a range of potato pests, including whiteflies, aphids and white grubs.
- For a real-world example of biological control in action, see how European growers successfully protected their potato crops using a combination of Trichoderma and beneficial nematodes in this case study by Koppert.
Organic vs. conventional compatible products
Not all biocontrol products are suitable for organic farming. Organic-compatible products must be approved/listed by certification bodies like EU Organic or OMRI. Always check the product label and local regulations to ensure it meets your farm certification and crop protection needs.
How to apply biocontrol effectively
Once you have selected a biological control product approved for your crop, growing system and target pest or disease, the next step is understanding how to apply the product effectively.
Ensure you:
- Check the labels of any products for specific application and dosage recommendations
- Check the safety guidance sheets and product facts sheets which some products have
- Check the shelf-life and storage requirements of your (potential) bioprotection product
It is important to follow guidelines that are available on the product labels and accompanying technical factsheets. This guidance will be specific to your crop, pest, region, and farming set-up. To get additional advice speak to an expert; ask your local distributor or extension agent, you can also find contact details of the biocontrol manufacturer on the product label.
Application timing and methods
There may be different ways to apply different bioprotection products, and it is important to know the most appropriate method for your own situation. However, some general advice is to apply products late in the day, so that the temperatures are not too high and the UV rays are not too strong, preventing product denaturation. Avoid windy conditions or spraying during or just prior to rain. Ensure you calibrate your spray equipment properly, prior to spraying. And understand the correct part of the plant to be applying the bioprotectant (‘right amount, right place, right time’). For more information, see our ‘Application of bioprotection products: A beginner’s guide‘.
Dosing, storage, and mixing tips
Ensure the correct dose is applied and ensure you are spraying the correct part of the plant (or soil) for optimum targeting of the pest or disease. Always consult the product label prior to application. Store products as instructed (usually cool, dry, and out of direct sunlight) and check expiration dates. Only mix with other products if the label says it’s safe to do so. Some combinations may reduce efficacy.
Field conditions: what to avoid
Avoid applying during extreme heat, direct sun, heavy rain, or strong winds. These conditions can damage living biocontrol agents or wash the products off before they act.
Integrating biocontrol in IPM plans
Crop rotation and soil preparation
Rotating potatoes with non-host plants like cereals or legumes helps break the life cycle of soil-dwelling pests such as wireworms and potato cyst nematodes. Incorporating cover crops can also suppress soil pathogens and improve soil structure. Proper soil preparation can create a favourable environment for beneficial microbes and entomopathogenic fungi that have been applied as biocontrol agents.
Using traps and monitoring tools
Early detection is critical for pests like Colorado potato beetle, aphids, and leafhoppers. Use pheromone or yellow sticky straps to track population trends. Monitoring lets you schedule your product application more precisely and avoid unnecessary treatments (and unnecessary costs).
Combining mechanical and biological tools
Mechanical controls, such as hand-picking beetles, using trap crops, or tilling to disrupt overwintering stages, can significantly reduce initial pest pressure on your potato crop. When combined with biocontrols like Bt or beneficial nematodes, these mechanical methods can enhance effectiveness, without disrupting the ecosystem.
Chemical pesticides
As a world leader in nature-based pest management knowledge implementation, CABI encourages Integrated Pest Management (IPM) as the preferred, ecologically-based approach to producing healthy crops, which allows for chemical pesticide use only as needed, and when adhering to measures that limit the exposure of people and the environment to them (see FAO, International Code of Conduct on Pesticide Management).
Before considering the use of chemical pesticides, farmers should explore all available non-chemical control solutions, as the ones listed above, and consult the CABI BioProtection Portal for identifying and applying suitable biological control products.
In case chemical pesticides are considered for use, farmers should look to select lower-risk chemical pesticides which, when used as part of an IPM strategy, help manage pest problems while minimizing harmful effects on human health and the environment. Agricultural advisory service providers can provide information on lower-risk chemical pesticides that are locally available and are compatible within an IPM strategy. These experts can also advise on the required personal protective equipment.
- For information on IPM of potato in Spanish, read this guide.
See some of our other crops guides:
- How to identify and manage major maize pests
- Rice pest management: Identification and control strategies to protect crop yield
- Mango Pests and Diseases: Symptoms and Control Guide
Frequently asked questions
What is the most common insect pest in potatoes?
The most common insect pest in potatoes depends on the region considered. For example, in North America the Colorado potato beetle, which feeds on leaves and can cause severe defoliation, is the most significant potato pest. Other frequent pests include aphids and the potato tuber moth.
How to control potato pests?
How to control potato pests?
Potato pests can be controlled using biological methods such as beneficial nematodes, natural substances such as neem, and fungal agents like Trichoderma, and other cultural and mechanical methods such as crop rotation and hand-picking of larvae.
What is sustainable pest control for potatoes?
Pest control for potatoes includes identifying the pest early and applying targeted biocontrol, mechanical, and cultural methods. This reduces damage while preserving the environment and beneficial insects.
What is the most common disease in potatoes?
Late blight is the most common and destructive disease in potatoes, often spreading rapidly in cool, moist conditions.
