_____________________________________________________________________________________________________ *Corresponding author: E-mail: gitanjali_devi@yahoo.in, gitanjali.devi@aau.ac.in; International Journal of Plant & Soil Science 34(9): 40-47, 2022; Article no.IJPSS.84526 ISSN: 2320-7035 Formulation of Entomopathogenic Nematode, Steinernema kushidai, their Survival and Infectivity Jisna George a , Gitanjali Devi a* and Badal Bhattacharyya b a Department of Nematology, Assam Agricultural University, Jorhat-785013, Assam, India. b Department of Entomology, Assam Agricultural University, Jorhat-785013, Assam, India. Authors’ contributions This work was carried out in collaboration among all authors. All authors read and approved the final manuscript. Article Information DOI: 10.9734/IJPSS/2022/v34i930911 Open Peer Review History: This journal follows the Advanced Open Peer Review policy. Identity of the Reviewers, Editor(s) and additional Reviewers, peer review comments, different versions of the manuscript, comments of the editors, etc are available here: https://www.sdiarticle5.com/review-history/84526 Received 04 January 2022 Accepted 09 March 2022 Published 16 March 2022 ABSTRACT The commercialization and large-scale use of EPNs are limited by their short shelf life in formulations and in storage, thus leading to poor quality and reduced efficacy against insects in the field. This study explored the effects of some formulations on survival and infectivity of infective juveniles (IJs) of entomopathogenic nematodes , Steinernema kushidai at 5 and 25°C for 6 weeks. In the formulations, the survival and virulence rate differed at different temperature with decrease over the period of time. The alginate retained most of the IJs and can be stored for a longer time at 5°C followed by sawdust formulation .From the economic point of view sawdust formulation shows better results. Keywords: Entomopathogenic nematodes; Steinernema kushidai; formulation; survival; infectivity. 1. INTRODUCTION Entomopathogenic nematodes (EPNs) have great potential as a biocontrol agent against various soil as well as foliar insect pests of economic importance. EPN are obligatory parasitic insects belonging to the Steinernematidae and Heterorhabditidae families [1]. They have a mutualistic relationship with pathogenic bacteria from the genera Xenorhabdus and Photorhabdus, which are both fatal to insects [2]. Because of their simplicity of mass culture, great lethality against important pests, and lack of safety concerns, EPN are Original Research Article