Mass Production of Entomopathogenic Nematodes- A Review

Abstract

Entomopathogenic nematodes, and their symbiotic bacteria, are promising agents for control of soil-borne insect pests. Two genera of nematodes, Steinernema and Heterorhabditis, have shown particular promise and a number of commercial products are now available. Commercialisation of entomopathogenic nematodes has entailed the development of cost-effective mass production technology. The development of appropriate technology will be reviewed culminating with a description of the current method of choice, liquid fermentation. The factors involved in the choice of appropriate commercial mass production technology will be discussed with particular reference to entomopathogenic nematodes. Commercial issues such as production costs (capital and variable), labour requirements and utility of process plant will be considered. Technical issues to be addressed will include maintenance of stock cultures, process monitoring, harvesting and downstream processing, and packaging and storage of the final, formulated product. The use of Quality Assurance and Quality Control procedures to ensure consistency of product yield and quality will be discussed. Mass production of entomopathogenic nematodes presents a number of problems peculiar to these particular biocontrol agents. These include the need to ensure optimum reproduction of two very distinct organisms, nematodes and bacteria, and the requirement for synchronisation of a population of multicellular organisms as they reproduce and undergo a number of distinct developmental changes. Further problems are raised by biological differences between Steinernema and Heterorhabditis with regard to development and reproduction. The significance of these problems for commercial mass production of nematodes will be highlighted