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BACKGROUND: The occurrence of Spodoptera frugiperda (J.E. Smith) in Asia was reported for the first time from Karnataka in 2018. This pest is widely distributed in India, causing significant damage to maize. Management of this recent invasive pest in maize‐growing regions of India relies on chemical control. Resistance is the greatest obstacle to the successful use of chemical insecticides to control this pest. Indiscriminate use of chemical insecticides destroys beneficial natural enemies, therefore effective and sustainable alternative control strategies are needed. In this case, the use of biological control agents is the alternative option to mitigate this pest. Thus, this study aimed to select virulent entomopathogenic nematodes (EPNs) isolates based on the laboratory assay and further to test the efficacy of virulent isolates in the field conditions along with commonly used chemical insecticide emamectin benzoate against S. frugiperda. RESULTS: Laboratory results revealed that both Heterorhabditis indica 1 NBAIIH38 and Steinernema carpocapsae NBAIRS59 caused 100% mortality in third‐ and fourth‐instar larvae of S. frugiperda, while these two species caused 85% and 72% mortality in pupae, respectively. When pupae of S. frugiperda were exposed to EPNs, pupae died after metamorphosis to malformed adults. All the nematode species were able to penetrate and reproduce within S. frugiperda larvae, but the reproduction rate for Heterorhabditids was higher than that of Steinernematids. Field trial results showed that H. indica 1 NBAIIH38 significantly reduced the number of larvae and leaf damage scores compared to S. carpocapsae NBAIRS59. Emamectin benzoate was more effective in reducing the larval population compared to EPN species. The cob yield was significantly higher in EPN‐ and emamectin benzoate‐treated plots than in untreated control plots. CONCLUSION: Overall, these experiments suggest H. indica 1 NBAIIH38 is a promising biocontrol agent against S. frugiperda in maize production. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

During 2018 summer season (April–May), several young (1–3-year-old) arecanut seedlings exhibited yellowing, drying, drooping and wilting symptoms in farmer's gardens located in Dakshina Kannada district of Karnataka, India. The longitudinal section of the infected seedlings showed extensive decaying of fibrous roots which extended up to the collar region and ultimately resulted in the death of young seedlings. A series of cultural, morphological, molecular characterization using multi-gene phylogeny and pathogenicity assays with Koch's postulates confirmed the association of Fusarium falciforme (FSSC 3 + 4) as the causal organism of arecanut root decay disease. To the best of our knowledge, the present study confirms the first report of root decay disease caused by F. falciforme in arecanut. [ABSTRACT FROM AUTHOR]

[Display omitted] • Native strain of Metarhizium anisopliae isolated from naturally infected adult of Helopeltis theivora. • In cage and field trials, M. anisopliae reduced H. theivora incidence in cocoa. • A M. anisopliae proved more effective in field condition by protecting the cocoa pods against H. theivora infestation. The tea mosquito bug, Helopeltis spp. is a destructive pest of cocoa across the globe. In the climate change scenario, the tea mosquito bug species complex, viz. Helopeltis theivora Waterhouse , 1886 , H. bradyi Waterhouse , 1886, and H. antonii V. Signoret, 1858, poses a serious threat to cocoa cultivation in India. Presently, systemic and/or broad-spectrum insecticides are used for mirid management by cocoa growers. However, concerns about their adverse effects on human health and the environment prompted us to search for alternative eco-friendly options for their management. Entomopathogenic fungi (EPF) are an effective and eco-friendly alternative to chemical insecticides for the management of cocoa mirids. The use of native strains of biological control agents improves their success rate. Hence, the present investigation was conducted to isolate, characterize and evaluate an indigenous insect-pathogenic isolate of EPF Metarhizium anisopliae against the mirid H. theivora. An extensive survey was conducted in the Dakshina Kannada district of Karnataka, India, to collect the adults of H. theivora naturally infected with entomopathogenic fungi. A pure culture of the EPF named as TMBMA1 was isolated from the infected adults. Based on the detailed morphological and molecular characterization, the isolate TMBMA1 was identified as Metarhizium anisopliae (Metsch.) Sorokin. The isolate TMBMA1 was found to be highly effective against H. theivora in an in-vitro bioassay and caused 100% insect mortality at 1 × 108 and 1 × 109 conidial suspensions 6 days post inoculation. Similarly, TMBMA1 was found effective in significantly reducing the incidence of mirids in field evaluations conducted for two consecutive years. TMBMA1 was found better than other commercial biopesticides and was comparable with the recommended chemical insecticide Lambda-cyhalothrin. In conclusion, our results reveal that the native EPF, M. anisopliae isolate TMBMA1 has great potential against the mirid H. theivora and can serve as an eco-friendly and sustainable alternative for mirid management in cocoa and other plantations in India. [ABSTRACT FROM AUTHOR]