Low-cost technology for entomopathogenic nematode large-scale production

Abstract

Entomopathogenic nematodes of the genera Steinemema and Heterorhabditis may provide a valuable alternative to chemical insecticides. The characteristics that make them excellent biopesticides include their wide host spectrum, the ability to search for and kill hosts rapidly, and their high virulence and reproductive rates. Furthermore, they are considered environmentally safe. The major constraint to overcome before the onset of commercialisation is their mass production. Entomopathogenic nematodes are currently mass-produced in vivo or in vitro, either in solid culture or in liquid cultivation. An overview of these mass production methods and an analysis of three different bioreactor designs are presented. The progress achieved in liquid culture due to an improvement on sexual contact between adults (better mixture of the solid phase), which results in higher yields (RF), as compared with those reported before, is demonstrated. This improvement in the area of bioreaction engineering allowed these biopesticides to become more competitive compared to chemical insecticides. However, further technological advances and biological studies towards a better understanding of physiology and genetics of the complex nematode-bacterium are still required.