News Plant Pest(s): Meloidogyne enterolobii: a threat to crops in Europe

What is Meloidogyne enterolobii?

Meloidogyne enterolobii is a nematode belonging to the group of threadworms (Nematoda). This very diverse group contains a small proportion of specialized plant parasites. Root knot nematodes (Meloidogyne spp.) are among the most important plant parasitic nematodes, as they are harmful to plants and cause yield losses in various crops worldwide.

In April 2022, M. enterolobii was added to the list of EU quarantine organisms. This means it is considered a serious risk to agriculture. Indeed, this nematode can affect many important crops, including pepper, tomato, cucumber, potato and various woody and herbaceous plants. In addition, M. enterolobii can reproduce on Meloidogyne-resistant tomato and bell pepper varieties, making it even more difficult to control the problem.

Life cycle and damage to plants

Root knot nematodes are microscopic. Their larvae (juveniles) hatch from an infested root and enter the soil in search of another suitable plant root. Once they penetrate the root, they turn plant cells into so-called giant cells, which provide them a permanent food. This weakens the plant and reduces yields.

The nematodes undergo several molts and develop into males or females. The females lay hundreds of eggs in an egg packet, which ends up in the root or soil. The presence of the nematode causes the plant to form nodules on the roots, which interferes with water and food uptake. This causes not only growth problems, but also a visible loss of quality in underground crops such as carrots, salsify and potatoes, rendering them impossible to process.

Distribution and risks in Europe

M. enterolobii is mainly found in (sub)tropical regions of North, Central and South America, Africa and Asia. However, research shows that this nematode can also survive in temperate climates. For example, it was found on rose plants from China and most recently in Portugal and in Dutch and Swiss greenhouses. This proves that the nematode can indeed establish itself in warmer parts of Europe and in greenhouses. In addition, it has been shown that some populations of M. enterolobii can reproduce on crops that were previously considered non-host plants, such as yellow mustard. This increases the risk of spread.

Research and control

Reliable research is needed to better understand and contain the spread of M. enterolobii in Europe. Inspections upon import and monitoring of infections are essential to prevent further introductions. In addition, more knowledge on the life cycle and survival rates of this nematode is required to assess its potential impact on agriculture and horticulture in temperate European climate zones.

This is why ILVO, commissioned by the FPS Public Health, Safety of the Food Chain and Environment, is participating in the EUPHRESCO project “MENTSURV” (2023-2026). This project investigates how M. enterolobii survives in temperate climate conditions and how it spreads within Europe. Partners in this research include the Dutch Food and Consumer Product Safety Authority (NVWA), the Austrian Agency for Health and Food Safety and the Murcian Institute of Agricultural and Food Research and Development (Spain).

ILVO and NVWA are studying how the nematode survives and reproduces in our climate, including on potatoes. This research helps to better assess the impact on European agriculture and develop effective control measures.

Control of imported plants

The ILVO Diagnostic Center for Plants (DCP) conducts analyses on behalf of the Federal Agency for the Safety of the Food Chain (FASFC) to investigate the presence of quarantine nematodes in imported plants.

For M. enterolobii, the focus is on tubers, such as ginger and sweet potato from countries where this nematode is present, such as the United States and several African countries. In 2024, M. enterolobii was found in 3% of the samples examined. Identification is done through an internationally recognized molecular technique (qPCR according to Kiewnick et al., 2015). These controls are essential to limit the introduction and further spread of this harmful species in Europe.