These include bacterial- (such as rhabditids) and fungal- (such as
aphelenchids) feeding nematodes. By grazing on bacteria and fungi, these nematodes
enhance the rates of C and N mineralization, which can benefit crop production. Many are colonizers with short life
cycles, producing many offspring, resulting in high population growth rates.
These nematodes
feed on more than one food source (bacteria, fungi, algae, nematodes, etc.).
These include many members of the nematode order Dorylaimida and some other
orders. Life cycle is similar to predatory nematodes as described below.
These nematodes
feed on other soil nematodes (both plant-parasitic and free-living) and on
other animals of comparable size. Nematodes in the nematode order Mononchida
are predacious. A few predators are also found in the order Dorylaimida and
some other orders. These groups of nematodes are persisters with longer life
cycles, producing fewer offspring, and resulting in slower population growth
rates.
Nematodes
that can parasitize insects. The entomopathogenic nematode that can kill or
hamper the development of the insect host, and is capable of mass production,
can be used as an effective biological control agent (Poinar 1979).
Information
on how entomopathogenic nematodes can be used as biological agents of insects
and the taxonomy and systematics of these nematodes can be obtained from:
http://nematode.unl.edu/wormepns.htm
http://www2.oardc.ohio-state.edu/nematodes/
http://csssrvr.entnem.ufl.edu/ctlweb/nem.htm