List of agricultural pest nematode species found worldwide

Agricultural pest nematodes are microscopic worms that can cause significant damage to crops worldwide.

The Heterodera avenae, also known as the oat cyst nematode, is a major pest of oats in Europe and North America.

Meloidogyne incognita, the root-knot nematode, is a highly damaging nematode species found on over 1,000 plant species, including tomatoes, potatoes, and okra.

Pratylenchus penetrans, the reniform nematode, is a common pest of soybeans in the United States and other parts of the world.

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Nematodes are tiny, parasitic worms that can cause significant damage to crops. They live in the soil and feed on plant roots, which can lead to stunted growth, reduced yields, and even plant death.

Paratrichodorus allius, a type of nematode, feeds on certain crops in central Oregon, but its host range is not fully understood.

To detect nematodes like soybean cyst nematode, root tissue must be included in soil samples to provide egg and cyst counts.

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Parasitic nematodes are tiny worms that feed on plants in the soil. They can be found in various parts of the world, including central Oregon.

These nematodes are classified based on where they live while feeding on the plant. To determine the correct species of nematode, it's essential to sample the correct component, either the root or soil.

Some nematodes, like Paratrichodorus allius, live within the root, while others, like lance, lesion, and reniform nematodes, live in the soil outside of the root.

Root-parasitic nematodes can cause significant damage to plants. In a survey of central Oregon crops, nematode damage was expressed as nematodes per 100 grams of soil or per 100 cubic centimeters of soil.

Nematode numbers can be multiplied by 20 to give the number of nematodes per 2000 grams of soil, which is equivalent to one "quart" of soil.

The lifecycle of parasitic nematodes can be completed in as little as one month, with some species able to complete four or more lifecycles in one growing season. Under favorable conditions, mature females can produce hundreds of eggs, leading to high population densities.

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Lesion nematodes are small, migratory endoparasites that feed on a wide variety of plants, making them a concern for farmers.

They are not typically found in the same field as SCN, but their numbers may increase in the absence of SCN.

Lesion nematodes cause lesions on roots, which can be similar in appearance to a fungal root rot disease.

Their feeding habits can lead to damage to plant roots, affecting the overall health and productivity of the plant.

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The root-knot nematode, Meloidogyne spp., is a major pest of many crops, including tomatoes, potatoes, and cucumbers.

These microscopic worms can cause significant damage to plants, stunting their growth and reducing yields.

The soybean cyst nematode, Heterodera glycines, is a specific type of nematode that targets soybeans, causing them to become stunted and yellow.

In the United States alone, the soybean cyst nematode is estimated to cause losses of over $1 billion annually.

The cereal cyst nematode, Heterodera filipjevi, is another type of nematode that attacks wheat and other small grains, causing them to become stunted and weakened.

The reniform nematode, Rotylenchulus reniformis, is a parasitic nematode that targets cotton, soybeans, and other crops, causing them to become stunted and yellow.

The burrowing nematode, Radopholus similis, is a major pest of bananas and other tropical crops, causing them to become stunted and weakened.

The Southern root-knot nematode, Meloidogyne incognita, is one of the most widespread root-knot nematode species across North Carolina.

It has an extensive host range, including vegetables, herbs, field crops, fruits, trees, ornamentals, and weeds. This nematode can infect and feed on a wide variety of plants.

Some examples of host crops include corn, cotton, soybean, sorghum, tobacco, wheat, rye, oats, barley, and alfalfa. On the other hand, peanut, sesame, and sunn hemp are not suitable hosts for this nematode.

Here's a breakdown of the host range of the Southern root-knot nematode:

Sting, Stunt, and Pin nematodes are ectoparasites that are largely confined to sandy soils.

These nematodes are not considered major pests of soybeans, but sting nematodes can be extremely damaging.

Sting nematodes are rarely of economic importance on non-sandy soils.

All three nematodes are ectoparasites, meaning they live on the surface of their host plant rather than inside it.

The Southern root-knot nematode is the most widespread root-knot nematode species across North Carolina.

This species can be found in tropical to subtropical regions such as southern U.S.A., China, central Europe, and Brazil.

There are four major root-knot nematode species, with the Southern root-knot nematode being one of them. The others are the Javanese root-knot nematode, the Northern root-knot nematode, and the peanut root-knot nematode.

The Southern root-knot nematode and the Javanese root-knot nematode can infect and feed on corn, while corn is a weak host to the Northern root-knot nematode.

Here are the root-knot nematode species that can infect corn:

The Southern root-knot nematode is the focus of this disease factsheet due to its widespread presence in North Carolina.

The Southern root-knot nematode has an extensive host range, affecting a wide variety of plants including vegetables, herbs, field crops, fruits, trees, ornamentals, and weeds.

Some of the crops that are susceptible to the Southern root-knot nematode include tomatoes, sweetpotato, pepper, eggplant, okra, basil, bean, cabbage, carrot, lettuce, and potato.

Vegetables and herbs are particularly vulnerable, with many different types of plants being affected.

Table 1 provides a breakdown of the host and non-host plants to the Southern root-knot nematode, highlighting the diversity of crops that are susceptible to this pest.

Field crops such as corn, cotton, soybean, sorghum, tobacco, wheat, rye, oats, and barley are also affected, while peanut, sesame, and sunn hemp are less susceptible.

Fruits and trees are also at risk, with many types of fruits including watermelon, cantaloupe, cucumber, and peach being affected.

Some weeds, such as nutsedge, morning glory, crabgrass, lambsquarter, and sicklepod, are also hosts to the Southern root-knot nematode.

Ornamental plants, including annual and perennial varieties, are also at risk, with many different types of plants being affected.

It's worth noting that the host status of strawberry to Southern root-knot nematode is somewhat inconclusive, but some varieties of strawberry are reported as resistant.

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The Southern root-knot nematode has a life cycle that's similar to other root-knot nematode species. It starts with eggs that hatch in warm, moist soil.

These eggs hatch into infectious second-stage juveniles, which then search for and penetrate actively growing plant roots near the root tips. They establish feeding sites called "giant cells" as they settle in.

The nematodes molt three times to become adults, and are fully enclosed by the root tissues. Adult female Southern root-knot nematodes typically lay approximately 150-1500 eggs each.

In optimal conditions, it typically takes 2-5 weeks to complete their life cycle. Root-knot nematodes thrive in sandy soils in tropical to subtropical regions.

Managing agricultural pest nematodes can be a challenge, especially with their broad host range. Routine soil sampling for nematode analysis is crucial to understand if a field has root-knot nematode and to monitor population counts.

Good weed management is essential to eliminate a potential food source for nematodes. Southern root-knot nematode can infect, reproduce, and survive on common weeds.

A DNA-based test is often required to determine the specific root-knot nematode species in the field. This information helps determine if there is a non-host crop that can be integrated into the cropping sequence.

The primary management strategies in an Integrated Pest Management (IPM) approach are outlined below:

Using a pathogen population threshold can aid in determining when to use management strategies and also reduces costs by avoiding treatments when populations are below economically impactful levels. Reviewing your nematode assay report is an important step in implementing an IPM approach.

Here are some common management tactics used to reduce populations of the nematode:

Table 1 lists the broad host range of Southern root-knot nematode, which makes management more difficult. Table 2 summarizes some chemical and biological management options for suppression of Southern root-knot nematode in corn.

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Root-knot nematodes are a common pest in soybean fields, with the southern root-knot nematode being more damaging than the northern root-knot nematode.

They can cause extremely stunted plants early in the season or early death during bloom and pod fill, and injury can be more serious in drought conditions.

Root galls are a distinctive feature of this nematode and make it easy to identify.

Lance nematodes are relatively large and can be found throughout soybean growing regions within the U.S., particularly in southern states.

They have a wide host range, making rotation an ineffective control method.

The soybean cyst nematode is the most important pest of soybean in the United States and Canada, with females producing hundreds of eggs that can lead to new infections.

Adult females can be observed on soybean roots during the growing season, and their presence can induce iron-deficiency chlorosis in some areas.

To identify soybean cyst nematodes, plants must be carefully dug from the soil, and the soil removed to expose the lemon-shaped nematodes, which are about 1/32 inch or 1 mm in diameter.