"Introduction to nematodes" presentation

A beautiful multimedia presentation entitled "An Introduction to Nematodes" has been produced by E.C. Mcgawley, C. Overstreet and M.J. Pontiff.  This presentation is hosted at the ONTA website and can be accessed here.

What are nematodes?

Nematodes are found in a wide variety of habitats, from the Antarctic to the hot springs in New Zealand. Free-living nematodes live in the soil and in freshwater and marine sands and muds. In soil they are important components of nutrient turnover. Other nematodes are parasites of almost every species of animal, including humans, and plant and cause enormous social and economic damage. They are also known as ‘eelworms’ and ‘roundworms’.

Nematodes are typically worm-like, except they are unsegmented. Essentially the body form is similar to a flexible cylinder with a rounded head and a pointed tail. They need at least a film of water for active movement, which is an undulating motion similar to that of an eel. The majority of nematodes are microscopic in size, although some species that parasitise animals are much larger and can grow to several centimetres in length.

Animal-parasitic nematodes parasitise man and his domestic animals, as well as wild animals. In humans, some 30 species of nematodes are of medical importance and are responsible for diseases such as elephantiasis and river blindness, and include the intestinal roundworm (Ascaris), the pin worm (Enterobius) and the hook worms (Necator).

Some species of nematodes, called entomopathogenic nematodes, can be used for biological control of insects. They invade insect pests and release bacteria, which kill the insect and enable the nematode to feed on the proliferating bacteria.

Plant-parasitic nematodes are pests of every food crop worldwide, and cause yield loss in all crops as well as damage to vegetables making them unmarketable. Some species feed on the outside of plant roots (ectoparasitic forms), whilst others invade the root and feed internally (endoparasitic forms). There are also species that parasitise the aerial parts of plants. Control strategies are varied and many are expensive and not available to developing countries. Research focuses on determining environmentally acceptable strategies, such as host resistance to nematode invasion, to control the pest.

Practical Guide to Plant Nematology

A field and laboratory guide to practical plant nematology has been produced by the International Institute of Tropical Agriculture and the International Maize and Wheat Improvement Center.  These guides are available in several languages and can be freely distributed.

The English version of the guide can be found here.

The Spanish version of the guide can be found here.

The Portuguese version of the guide can be found here.