Future Possibilities for Using Entomopathogenic Nematodes

Abstract

The potential world market for entomopathogenic nematodes (ENs) could reach several hundred million $US per annum if these organisms are optimally developed and exploited. Currently, the market for ENs represents only a tiny fraction of this potential (even though ENs are already second only to Bacillus thuringiensis (Bt) in biopesticide sales).
However, a continually expanding research effort around the world has developed a sound knowledge base from which to focus on the range of basic, strategic and tactical R & D that is now required to develop ENs much further. By 2005 we should see the current world collections of a few hundred isolates, representing some 30 or 40 species, expanded to many thousands of isolates of over 100 species. This will have helped to increase substantially the range of targets susceptible to ENs and, because fewer of the new, superior nematodes will be required, greatly reduce application rates and therefore costs. It will also doubtless have been possible to improve good strains still further by cross breeding, artificial selection and even genetic manipulation, as well as by mixing and matching various ENs and symbiotic bacteria. Because of IP considerations, molecular biology will become increasingly important for genetically characterizing strains of both nematodes and bacteria and will be used to help screen large numbers of isolates and in field trialing mixtures of strains. A large increase in numbers of patents concerning the use of particular EN species and strains for the control of specific insect pests can be expected. A new series of application technologies will have been developed to deliver ENs as close to their insect targets as possible in the most favorable environment; some will enable improved soil penetration, others will involve baiting and there may well be better means of using ENs to control some leaf eating insects.
In addition to major cost cuttings achieved using superior nematode strains and improved application technologies, further, though not so significant, reductions can be expected from improved efficiency in production methods. Once the most appropriate EN has been developed for a large market segment it will doubtless most efficiently be produced using large-scale liquid fermentation, carefully tailored for that particular species/strain. However while species/strains are being continually improved and superseded the more flexible solid culture methods will still have a part to play. By 2005, it can be expected that there will be available some EN products with a shelf life approaching one year at ambient temperatures and others with at least 6 months. These improved shelf lives will result from careful attention to methods of induction into cryptobiosis and resulting biochemical and respiratory rate modifications specific for each species, and possibly even each strain. Packaging that enables maintenance of water activity while allowing adequate oxygen exchange will have become increasingly important as shelf life is extended. For all aspects of culture maintenance, production, formulation and packaging, strict quality control procedures will have been developed and practiced as a part of ensuring consistent results. EN commercialization will go from strength to strength hand in hand with a wealth of R & D that will benefit all working on these important organisms.