Opportunities and challenges of entomopathogenic nematodes as biocontrol agents in their tripartite interactions

Abstract

Background: The complex including entomopathogenic nematodes (EPNs) of the genera Steinernema and Heterorhabditis and their mutualistic partner, i.e., Xenorhabdus and Photorhabdus bacteria, respectively possesses many attributes of ideal biological control agents against numerous insect pests as a third partner. Despite authenic opportunities for their practical use as biocontrol agents globally, they are challenged by major impediments especially their cost and reliability. Main body: This review article presents major attributes of EPNs to familiarize growers and stakeholders with their careful application. As relatively high EPN costs and frequently low efficacy are still hindering them from reaching broader biopesticide markets, this is to review the latest findings on EPN strain/species enhancement, improvement of production, formulation and application technology, and achieving biological control of insects from the standpoint of facing these challenges. The conditions and practices that affected the use of EPNs for integrated pest management (IPM) are identified. Besides, efforts have been made to address such practices in various ways that grasp their effective approaches, identify research priority areas, and allow refined techniques. Additionally, sampling factors responsible for obtaining more EPN isolates with differential pathogenicity and better adaptation to control specific pest(s) are discussed. Conclusion: Specific improvements of EPN production, formulation, and application technology are reviewed which may help in their broader use. Other diverse factors that optimize EPNs to constitute a cost-effective, value-added approach to IPM are also demonstrated.