Logo: Spiral nematode encircling African continent
Home
About Us
Nematology in SA
News
Symposia

On this page

What are nematodes?

 

Related links

SASPP The South African Society of Plant Pathologists promotes Plant Pathology in Southern Africa by acting as the official mouthpiece of Plant Pathologists in Southern Africa

IFNS The International Federation of Nematology Societies serves as a worldwide interface for Nematology societies promoting communication, education, research and outreach

ARC The Agricultural Research Council promotes the agricultural and related sectors through research, technology development and transfer.

SON The Society of Nematologists is an international organization formed to advance the science of nematology in both its fundamental and economic aspects.

PRF The Protein Research Foundation's main objectives are to replace imported protein for animal use with locally produced protein, but also to promote better utilisation of protein. These objectives are promoted through funding research and technology transfers.

IAPPS The International Association for the Plant Protection Sciences strives to insure production of sufficient quality of food/feed/fiber for a growing world population and to advocate implementation of sustainable plant health management strategies.

Abstracts from simposia

1985

1987

1989

1991

1993

1999

2001

2003

2005

2007

2009

2011


 

What are nematodes?

Nematodes (also called eelworms or roundworms) are the most abundant multicellular animals on earth. They belong in the Phylum Nematoda of the kingdom Animalia. Nematodes are found in large numbers in films of water in all natural soils, in fresh and marine waters from the polar regions to the equator, in humus and decaying plant tissues, and as parasites in moist tissues of most groups of animals, ranging from other nematodes, earthworms, insects, and molluscs to livestock, household pets, and humans

Many species that infect vertebrate animals and humans can be more than 5 cm long and are visible without magnification. Free-living microbe-feeding nematodes and plant-infecting species, most of which are in range of 0.5 to 2 mm long, generally cannot be observed in detail without a microscope.

Nematodes are mostly microscopic and generally translucent and thus nearly impossible to see in the soil, except for the females of some species, which swell and become pyriform, reniform, saccate, or lemon-shaped in the adult stage. Most plant-parasitic are elongate and threadlike throughout their life cycles, and all are of this morphology when they hatch from the egg. Only about 10% of all described nematode species are plant parasites. About 15% are animal parasites, about 50% are marine nematodes, and 25% are free-living.

Different species of plant-parasitic nematodes can inhabit and infect most living parts of plants, including flower buds, stems, leaves, and roots. Over 3 billion nematodes can be present in 0.4 ha of land. Many species occur in the top 30 cm of soil, but some are more common at deeper levels. A kilo of soil in a cultivated fertile field with a heavy plant cover generally contains 10 to 20 species belonging to diverse genera, including ecto– and endoparasites, predators, and microbe-feeding or saprophytic types.

From: Diagnosing plant diseases caused by nematodes by Malcolm C. Shurtleff and Charles W. Averre III, published by the American Phytopathological Society.

 

Dagger nematode feeding on root tip

Citrus nematodes on roots

Cyst nematode egg with emerging larvae