Synergistic effect of entomopathogens against Spodoptera litura (Fabricius) under laboratory and greenhouse conditions

Abstract

Background Entomopathogens such as nematodes, bacteria and fungi are well recognized for their biocontrol potential. This study was carried out to examine the insecticidal properties of the Heterorhabditis bacteriophora Poinar, Beauveria bassiana Balsamo-Crivelli, Bacillus thuringiensis Berliner, individually and in combination against 3rd instar larvae of Spodoptera litura Fabricius (Noctuidae: Lepidoptera) under controlled laboratory and greenhouse conditions at Eternal University, Baru Sahib, Sirmaur, Himachal Pradesh. Results The results demonstrated that the combined applications of the tested entomopathogens resulted in 100% insect mortality under the laboratory conditions. Among the individual concentrations, applications of 200 IJs/ml were noticed highly virulent with (98%) mortality, followed by B. thuringiensis (96%) and then by B. bassiana (92%). However, single treatments were also evaluated that further showed a highest mortality in the target pest by H. bacteriophora, followed by B. thuringiensis. Among the combined treatments by H. bacteriophora plus B. thuringiensis (200 IJs + 1 × 1012 CFU/cm2) more effective caused (100%) mortality were noticed in the laboratory and (28%) under the greenhouse conditions than H. bacteriophora plus B. bassiana (200 IJs + 1 × 1010 conidia/cm2) that caused (100%) mortality and (34%) damage under both, laboratory and greenhouse conditions. Conclusion Laboratory bioassay and greenhouse evaluation tests demonstrated that the combined sprayed treatments showed reliable and fast synergism. This study could be recommended to the farmers to control the pest.

Combined Efficacy of Biorational Insecticides against Potato Leafworm Spodoptera litura Fabricius (Lepidoptera: Noctuidae) Under Laboratory and Field Conditions

“…Our results corroborate the results of previous studies demonstrating significant toxicity of botanical pesticides including neem (A. indica) and tobacco (N. tabacum) extracts and of non-conventional synthetic insecticides including flubendiamide and spinetoram against different armyworm and other lepidopterous pest species (Nagal and Verma, 2015;Liu et al, 2017;Ayyub et al, 2019;Duarte et al, 2019;Thakur and Srivastava, 2019;Dáder et al, 2020;Phambala et al, 2020;Kong et al, 2021;Hernandez-Trejo et al, 2021;Thakur et al, 2022). Although most of the insect hosts become dead within few days by the bacterial or viral induced spectcima (Lacey, 2017;Soumia et al, 2021) and the observation at 5 th day of bioassay or microbial exposure was enough to see if these are effective against the S. litura larvae.…”

Effectiveness of Two Entomopathogenic Nematodes (Nematoda: Rhabditida) Populations in Controlling Fall Armyworm [(Spodoptera Frugiperda) Lepidoptera: Noctuidae] on Maize

“…Further evidence of resistance to Cry1Fa, pyrethroids, and organophosphates in FAW populations was reported by Santos-Amaya et al (2016). As an alternative approach, entomopathogenic nematodes (EPNs) and fungi have gained attention in the management of insect pests (Javed et al, 2019;Gulzar et al, 2020;Shehzad et al, 2021Thakur et al, 2022) and offer potential integration into Integrated Pest Management (IPM) programs for FAW control in maize. Thakur et al (2022) highlighted that the application of EPNs against insect pests carries a higher degree of safety for both humans and the environment compared to synthetic insecticides application.…”

Endosymbiotic microbes from entomopathogenic nematode (EPNs) and their applications as biocontrol agents for agro-environmental sustainability

“…Undoubtedly, these endosymbionts may become a favourable substitute in increasing the biological control of numerous phyto-insect pests as well as pathogens. EPN-associated bacterial endosymbionts have a high potentiality for agricultural pest control due to the toxic compounds and proteins produced as secondary metabolites (Thakur et al 2022a(Thakur et al , 2022b. The present review deals with distribution, identification and culturing practices of endosymbionts associated with EPNs.…”