Development of novel insecticidal wettable powder formulations of heterorhabditis indica strain nbaii hi1 for the biological control of root grubs in small cardamom

The complex including entomopathogenic nematodes (EPNs) of the genera Steinernema sp and Heterorhabditis sp 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 bio-control agents globally, they are challenged by major impediments especially their cost and reliability. This review article presents major attributes of EPNs to familiarize growers and stakeholders with their careful application. Novel Entomopathogenic nematode (EPN) formulation for the biological control of insect pests the wettable powder formulation of the EPN, Heterorhabditis indica (strain NBAII Hi1) has been developed and found effective for the management of white grubs in arecanut, banana, sugarcane, potato and corn. The novel formulation has improved shelf-life wherein at least 90% of the juveniles are viable even after eight to twelve months of storage at a temperature of between 25 and 37°C and exempted from CIB registration. Field demonstrations of the formulation were carried out in Kerala and Around 13000 Ha small cardamom fields were applied with WP formulations of H. indica @ 4-5 kg/acre respectively. The technology could reduce the small cardamom root grub incidence by 62-78%. ICAR-KVK, IDUKKI has distributed, more than 11000 Kg of WP EPN formulation to the farmers for the management of root grubs in small cardamom. 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. Specific improvements of EPN production, formulation, and application technology are reviewed which help in their broader may use. Other diverse factors that optimize EPNs to constitute a cost-effective, value added approach to IPM are also demonstrated.