41st Annual Meeting of the Society for Invertebrate Pathology
and 9th International Conference on Bacillus thuringiensis

Nematicides have been used to control plant parasitic nematodes, but over the last decade legislative measures have restricted their use as they are amongst the most toxic compounds used in agriculture. Therefore alternative approaches are being explored. These range from the development of resistant varieties and genetic engineering to the development of biological control agents. The life-cycle of plant parasitic nematodes includes two levels of trophic interaction, one between the plant and the parasitic nematode, and another between the nematode and any microbial pathogens present in the soil. Therefore the cuticle is an organ that provides a barrier between the nematode and its environment. The cuticles of plant parasitic nematodes have exhibit inter and intra specific variability with respect to the nematode hyperparasite Pasteuria penetrans. Endospores of this Gram positive obligate bacterium can adhere to and infect one strain of nematode but not another. This variation appears to be as great in parthenogenetically reproducing plant parasitic nematodes as in amphimictic reproducing groups. The implications of this variation for the population dynamics of the hyperparasite will be discussed.