Longidorus macrosoma

Longidorus macrosoma is a soil-dwelling nematode belonging to the family Longidoridae, order Dorylaimida. Commonly known as a type of needle nematode, it is an ectoparasite that lives in the soil and feeds on plant roots. Its presence in the root zone is a major concern for commercial growers, as it can cause significant agricultural loss through direct damage and disease transmission.

This nematode has a wide host range, attacking various crops, including fruit trees, strawberries, raspberries, and several vegetable species. It typically thrives in moist, well-structured soils. The pest is highly mobile within the soil profile, allowing it to migrate towards favorable root systems to maintain a consistent food supply throughout the growing season.

The biological cycle of Longidorus macrosoma involves several juvenile stages and adults, all residing in the soil environment. Using a specialized, needle-like feeding apparatus called an odontostyle, the nematode penetrates the root tissues. Its reproduction rate is relatively low compared to other nematodes, but its longevity and feeding capacity make it a persistent problem in field settings.

Damage symptoms often manifest as poor plant vigor, stunted growth, and yellowing foliage, which are easily mistaken for nutrient deficiencies or drought stress. The most critical aspect of its pathogenicity is its role as a vector for nepoviruses, such as the raspberry ringspot virus. By transmitting these pathogens, the nematode can lead to systemic infections that drastically reduce crop yield and quality.

Effective management requires an integrated pest management (IPM) strategy to minimize population density, as eradication is notoriously difficult. Recommended practices include:

• Planting certified nematode-free nursery stock.
• Utilizing crop rotation with non-host species to interrupt the nematode life cycle.
• Implementing soil solarization or fallowing in greenhouses.
• Application of nematicides or soil fumigants in high-risk zones, strictly following local regulations.