Red ring nematode facts for kids

The red ring disease is a serious problem for coconut palms and African oil palms. It is caused by a tiny worm-like creature called a nematode. Its scientific name is Bursaphelenchus cocophilus. People also call it the red ring nematode. This name comes from the red ring it makes inside the tree trunk.

Why the Red Ring Nematode Matters

This tiny nematode can cause big problems for palm trees. It can destroy up to 80% of trees in some oil palm farms. Usually, it causes about 10% to 15% loss in coconut and oil palm trees. The biggest money losses happen in coconut, oil palm, and date palm farms.

The red ring nematode is one of only two types of Bursaphelenchus nematodes that cause major economic damage. Because it is so harmful, many countries check very carefully for this nematode. They want to stop it from spreading to new places.

Where the Nematode Lives

You can find the red ring nematode in Central and South America. It also lives on some islands in the Caribbean Sea.

What Plants It Attacks

This nematode can attack many different types of palm trees. It can infect over 17 kinds of palms. This is probably more than half of all palm types.

How to Identify the Nematode

The red ring nematode is about 1 millimeter long when it is an adult. It has a special feeding part called a stylet, which is like a tiny needle. This stylet is about 11-15 micrometers long.

Female nematodes have a rounded tail. Male nematodes have seven small bumps called papillae near their tail. They also have special structures called spicules and a spade-shaped bursa. These parts help scientists identify the nematode.

The Nematode's Life Cycle

The red ring nematode has a typical life cycle for a plant parasite. It goes through four molts, which means it sheds its skin four times, before it becomes an adult. Its whole life cycle takes about ten days.

A special stage called the J3 or "dauer" stage helps the nematode survive. This is also the stage that can be spread to new trees. The nematode needs an insect to help it move from one palm tree to another.

How Insects Spread the Nematode

The main insect that spreads the red ring nematode is the Rhynchophorus palmarum. This insect is also known as the South American palm weevil. The weevil carries the J3 stage of the nematode.

Female weevils can have the nematodes inside their bodies, near where they lay eggs. When a female weevil lays her eggs in a palm tree, she also spreads the nematodes. This is how the tiny worms get into new, healthy palm trees.

How the Nematode Harms Palm Trees

When a palm tree is infected by the red ring nematode, it shows certain signs. The oldest leaves on the tree start to turn yellow. This yellowing is called chlorosis.

The most obvious sign is a clear red or brownish ring inside the trunk of the tree. This ring is what gives the disease its name. If you cut open an infected tree, you can see this distinct red ring.

Managing the Disease

To control the red ring disease, finding infected trees early is very important. This can help save other trees on a farm. If a tree is found to be infected, it must be removed.

First, the infected tree is treated with a special chemical to kill the nematode. Then, the tree is cut down. It is important not to leave the stump behind. If the stump stays, the weevils can still lay eggs there, which helps the nematode spread more.

Another way to manage the disease is by trapping the weevils. Trapping these insects can greatly reduce the disease. For example, it can lower the number of infected trees from 10% to just 1%.

See also

In Spanish: Bursaphelenchus cocophilus para niños