Mass culture and formulation of entomopathogenic nematodes for improved field application against key insect pests

EPNs control multiple insect pests and have been successfully produced and formulated into a biopesticide. Key to their commercial success is the development of a mass production protocol using native species. The development of a novel standard protocol for mass production for future commercialization was the main objective.

The mass production of entomopathogenic nematodes, using in vitro liquid culture methods, was used. To optimize the developed mass production method (the production of nematodes (IJ) per ml of growth medium), various factors such as protein source, lipid source, yeast source, inoculum concentration and bacterial inoculum concentration have been assessed.

Egg yolk was found to be increase yields to 3 x 10⁵ IJs/ml. Yield increases reduced cost by 77%.

Bioreactor trials yields comparable with shake flasks. Optimal nematode and bacterial inoculation decrease the variation in IJ yield.

Significant progress with the in vitro liquid culture method of H. zealandica. 

Optimizing the in vitro liquid culture process of S. yirgalemense has been especially successful with 3 x 10⁵ nematodes per ml of the artificial medium in liquid culture. Proof of concept for future commercialization has been supplied by harvesting the same number of nematodes in home designer desktop fermenters.

Research with biocontrol agents is a long-term investment and should be planned with a continuation plan for commercialization in mind. Training and expertise are lost with the students.