What Is Eating My Pea Plants Common Pests And Diseases Of Pea Plants

What is Eating My Pea Plants? Common Pests and Diseases of Pea Plants

Pea plants (Pisum sativum) is a herbaceous legume from the family Fabaceae. During a trip to the supermarket, you can find different shapes and sizes of peas because this green vegetable has a lot of varieties. Their famous seeds and pods are not only delicious; they are also full of nutrients. Even though many varieties are available, all require general pea plant care and maintenance. This knowledge is crucial for you to have a bountiful harvest.

5 Best-Selling Pea Plant Seeds

Nonetheless, problems are inevitable in growing your vegetation. Whether you are a pro or a beginner in growing vegetables, pests will always try to destroy your plants. Do not worry; this article will also help you resolve these issues. As you continue to read, we will help you further understand what is eating your pea plants and the common pests and diseases you can encounter while growing them.

photo of a pea pod
Photo from PxFuel

What is Eating My Pea Plants?

1. Aphids

group of aphids under a leaf's surface


Photo by Whitney Cranshaw, Colorado State University / Â© Bugwood.org

Pea aphids (Acyrthosiphon Pisum) are tiny, pear-shaped, soft-bodied insects that commonly reside on your pea plant before or during its flower season. They are often not noticed because of their small size and green color. These critters feed on your plant’s leaves and flowers and can, therefore, result in a significant decrease in harvest.

One of the main signs your pea plant is infested with aphids in the presence of sticky honeydew.  As aphids feed on your plant, they excrete this transparent-sticky liquid that can also attract ants and bring on more damage.

ant harvesting a honeydew from aphids


Photo by Judy Gallagher

Pea Enation Mosaic Virus

Furthermore, always check your plant for early signs of aphids as they bring pea enation mosaic virus. When infected with the virus, leaves crinkle and become yellow. The affected parts of the plant also become dysfunctional. As a result, the plant stops growing and produces flowers that will not turn into pods.

Pea enation mosaic virus symptoms visible in pea leaves


Photo by Paul Koepsell, 1980

The next paragraphs will discuss preventive measures and management techniques if your plant is infested with aphids or if they are infected with the virus. Before anything else, remember to do the following measures before the flowering of your pea plant. You do not want to do these steps when it is already too late.

First, you should have companion plants that attract aphid predators near your peas. For example, many nectar-producing flowers draw ladybeetles a known aphid killer. Lacewings and hoverflies are natural enemies of aphids, as well.

Next, situate your pea plants near herbs that repel aphids. Examples are basil and rosemary. Aphids hate these plant-strong smell. Other plants that repel aphids include catnip, marigold, and cilantro.

Third, spray high pressured water on aphids to drive them away from your plant. Driving these insects with water is an effective technique if aphid infestation is still controllable. Many pea plants can tolerate low to medium levels of infestation. On the other hand, if a huge number of aphids are already present, you can use insecticides as a last resort.

2. Mexican Bean Beetles

Mexican Bean Beetle adult on a leaf


Photo from Lou Nottingham / CC BY-SA

Mexican bean beetles (Epilachna varivestis) look like lady beetles that are tan to yellow colored. They have sixteen black spots and their size is about ¼ inch long. The adult beetle’s body changes color as they grow older and can become bright-yellow to orange-yellow.

Mexican Bean Beetle pea plant pest larva and egg


Mexican Bean Beetle larva and eggs photo from Growveg.com

The adults can lay 30-40 eggs at once on the underside of your plant leaves. Then, after maturing into yellow, spiny larvae, they will eat your plant. One of the obvious signs you are infested is the presence of skeletonized leaves. When not controlled early, they can also eat young bean pods. In worst cases, these pests can take the life of your plant.

For you to get rid of these, you should first check the undersides of your plant leaves for eggs and larvae. Do this particularly from early spring until June. Their striking color makes their existence obvious so scrape them off of your pea plant and smash them immediately as you see them.  In addition to manually removing them, you can also purchase Pediobius foveolatus. Pedio wasps are natural predators of these pesky beetles.

Adult Mexican bean beetle leaving the characteristic 'skeletonized' look on a pea leaf


Adult Mexican bean beetle leaving the characteristic ‘skeletonized’ look on a pea leaf, photo by Stephen Ausmus

If Mexican bean beetle infestation gets out of your control, you can opt to use insecticides to get rid of them completely. However, be cautious when using such chemicals because some also drive away beneficial insects.

3. Pea Weevils

adult pea weevil


AJC1 from UK / CC BY-SA

Pea weevils (Sitona lineatus) come out in spring. Adults are grayish-brown in color while larvae appear as off white with light brown heads. Because of their feeding pattern, they leave characteristic U-shaped notches around the pea plant leaves edges.


Pea leaf weevil injury photo from Real Agriculture

Generally, these do not cause much harm to adult plants even if the damage may seem extensive. However, adults also lay eggs on the soil surface near young pea plants. When your pea plants are still small and they become infested with weevils, great damage can arise.

The larvae of these troublesome insects eat through the pea’s seeds as well which results in holes that make them inapt for further development. Aside from the damage on the plant seeds, weevils also attack the roots.

The most effective way to prevent weevils from destroying your pea plants is to make sure your seedlings are protected. During development, water young plants regularly as support for their growth. Most importantly, do not forget to monitor often for possible weevil activity.

Other Diseases of Pea Plants

1. Downy Mildew

The causative agent of downy mildew is the fungus Peronospora viciae. The fungus spores can stay within the soil for up to 15 years. If there is debris left particularly from affected crops, sowing pea plants in the same area can lead to severe infections.



Signs that your pea plant is suffering from this disease include stunted growth and distorted stems. Additionally, you will also observe yellowish spots on the leaf’s top surface. Moreover, moldy growth will also appear on the underside of your pea leaves (refer to the photos above). The cottony growth color can range from white, purple to gray. What is worse, parts of your plant which are infected can turn yellow and wither. The fungus can also grow inside developing pods. Your pea plant will have a considerably hard time producing fruits if it is suffering from this disease.

You can prevent downy mildew by making sure that your soil has no history of growing plants infected with the fungi. Also, burn affected plant debris to destroy leftover spores. For instance, if a harvest includes pea plants that are infected, stop planting peas in the same area. Furthermore, make it a habit to rotate crops for at least 3 to 5 years so your soil will not continue to harbor the fungi.

2. Powdery Mildew

Powdery mildew is another fungal disease that can harm your pea plants and suppress its growth. The causative fungus is Erysiphe pisi. As the disease name implies, a layer of powdery growth will develop on the surface of your plant’s leaves and pods. This mildew is made up of millions of spores that are easily carried out by the wind to infect not only the other parts of your plant but also the nearby vegetation.

Powdery mildew symptom on a pea plant


Photo from CropPro


pea pod infected with powdery mildew


Photo from CropPro

This disease usually starts as small, circular white spots with a powdery texture on your plant’s leaves, fruits, and stems. The fungi will then spread across the whole plant. When the infection becomes severe, damaged parts turn yellow, dry, and become disfigured. These parts will eventually die.

It is very hard to salvage plants severely infected with powdery mildew so proactive prevention is the best way to control it. As a prevention technique, ensure that your plants get enough sunshine because fungi thrive in shady environments. Moreover, prevent overcrowding of plants within your lawn because this will result in a humid area that is highly favorable for fungi growth. If a mild infection is present, use overhead irrigation to wash off mildew on leaves.

3. Root-Knot Nematodes


Photo by Scot Nelson

From the genus Meloidogyne, root-knot nematodes are parasitic, worm-like animals that are common in soil. These are very small creature and infection with root-knot nematodes produces non-specific symptoms on your pea plant itself. More often than not, the only way you can diagnose them is when the symptoms are already apparent. This is why you need to watch out for physical signs like stunted growth, yellow discoloration, and wilting.

If present in the soil, these invade the root tips of your pea plants. As they grow and develop within the roots, the surrounding tissues enlarge which may look like knotted segments. These lumps develop all over your plant roots and can consequently cause root rot in severe conditions.

Make sure to destroy all affected plants if these nematodes are found. You can minimize the presence of root-knot nematodes in your soil by frequent tilling of the field before planting. Next, expose the soil to direct sunlight to reduce the parasite population. Lastly, practice crop rotation. This practice can significantly reduce the risk of susceptible plants being re-infected.

Additional Precautionary Measures Against Pests and Diseases

1. Try your best to find and plant resistant pea plant varieties. A lot of tolerant peas are already available. Such varieties are not easily damaged and can often outgrow common pests and diseases. These are much easier to maintain.

2. Rotate pea crops at least every 2 years. Do not settle and plant the same crops for long periods. This is essential if you want to prevent the accumulation of soil-borne disease and pathogens. Because peas increase the soil’s nitrogen content, you can plant other crops to benefit from this extra nutrient.

3. Clean and disinfect gardening tools before and after you use them to prevent cross-contamination.

4. Monitor the environment where your pea plants are grown. Plough the area thoroughly before you plant as this can also help in destroying fungal spores and other possible pathogens. Additionally, make sure your lawn can receive sufficient sunlight. Look out for parts that remain damp and cool for these can be a haven for harmful molds. Furthermore, guarantee enough air circulation around your pea plants to prevent fungal development.

5. Use protective chemicals against fungi and harmful insects. For instance, you can treat your pea seeds with fungicides before planting as a preventive measure against molds. Examples of effective solutions against fungi you can use include neem oil, potassium carbonate, and bicarbonate solution. Also, you can opt to use commercial fungicides such as Eagle 20EW, Liqui-Cop, and Fertilome 11377.

Next, pyrethrum-based insecticides are efficient for repelling common pea pests. Aside from this, other insecticides are also effective as long as you use them with caution. It is better to use chemicals only as a last resort.

Peas Growing Tips

1. Planting

Grow peas in a full sun area. Peas grow very well on well-drained soil. Add some aged compost to the planting bed for best yield as peas grow on average soil.

2. Planting Time

Sow peas straight in your garden 3 weeks before the last frost sping. To make sure, sow peas when the soil temperature is at least 40°F.

In moderate-winter areas, peas can be planted 8 to 10 weeks before the first frost in fall; plant peas during the winter in frost-free regions. For a prolonged harvest, plant early, midseason, and late-season varieties on the same day.

For a summer pea crop, sow heat-tolerant pea approximately 3 to 4 weeks after the first sowing or about 2 to 4 weeks after the last frost in spring. Where summers do not get hot, peas can be sown throughout the summer.

Fall pea crops should come to harvest 7 to 14 days before the first frost in fall. Plant an early variety in late summer, timed to mature before the frost. When planting peas, keep this in mind: young pea plants are frost tolerant, but peas blossoms and pods are frost-sensitive.

3. Care

Peas grows best when supported. Place a trllis, stakes, or long twiggy branches so that peas can climb. Place the support at planting time.

Keep the peas moist but not overly moist to avoid mold build-up and also seedlings will rot in wet soil so make sure that it is moist enough. When peas grow vines bloom and begin to form pods, increase the water. Watch for pests daily and spray the pest away with a blast of water and handpick larger pests.

4. Harvest

  • Peapods are maturing from the bottom of the plant up.
  • Pick snow peas when they are already tender and easily bent.
  • Pick snap peas when their pods are just swelling. Riped snap peas pods will “snap” when bent.
  • Pick shelling peas when they turned bright green and not before the pods look waxy.

Remember to pick all ready to harvest peas frequently to keep the plants producing.


No matter how much you care about your pea plants, pests and diseases will always be there to attack them. Pests that can eat and harm your pea plants include pea aphids, Mexican bean beetles, and pea weevils. Next, your plants can also suffer from fungal infections like powdery and downy mildew. Lastly, parasites like root-knot nematodes might also target your plant.

That is why it is of utmost importance that you are familiar with these insects and pathogens that are dangerous to your plants. Moreover, knowing the symptoms is also advantageous for early detection and treatment. The ultimate key to avoiding pea plant pests and diseases is proactive prevention.

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