Browsing by Author "Mahadevan Raghuraman"

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Bioefficacy, environmental safety and synergistic impacts of biorational formulations against whitefly, leafhopper and blister beetle in organic okra ecosystem
(Cambridge University Press, 2021) Satyapriya Singh; Gulab Singh Yadav; Anup Das; Biswajit Das; Hidangmayum Lembisana Devi; Mahadevan Raghuraman; Amit Kumar
Whitefly (Bemisia tabaci Gennadius), leafhopper (Amrasca biguttula biguttula Ishida) and large yellow-banded blister beetle (Mylabris phalerata) cause considerable damage to okra, especially under organic farming. Thus, the present study was carried out to test the bioefficacy and environmental safety of six naturally derived components [indigenous water plant extracts, i.e. chilli (Capsicum annum), garlic (Allium sativum L.) and neem (Azadirachta indica A. Juss.) along with cow urine in three different combinations, one commercial botanical (azadirachtin 0.15%), and two formulated entomopathogenic fungi (Verticillium lecanii and Beauveria bassiana)] on aforesaid pests for two consecutive years at field scale. In addition to this, the eco-toxicological effect of naturally derived components was also studied on natural enemies' populations, viz. spiders and coccinellids. Quaternary mixture application of chilli, garlic, neem leaf and cow urine (CGNC) at 10% w/v was found effective in reducing leafhoppers (94.6%), whiteflies (95.2%) and blister beetle (94.6%) over control. Okra treated with CGNC produced a higher marketable fruit yield (18.44 mg/ha) than those of other treatments. It was also observed that the application of CGNC had no phytotoxic symptoms on okra plants. Application of CGNC was found safer to the natural enemy's population (spiders and coccinellids). Thus, the study suggests that CGNC can be considered as a potential source for managing the population of whitefly, leafhopper and blister beetle without affecting the ecology of natural enemies and it could be a viable eco-friendly option in organic okra production for ensuring food safety and healthy environment. Copyright © The Author(s), 2021. Published by Cambridge University Press.
Evaluation of predatory potential and prey stage preference of mirid bug, Nesidiocoris tenuis on tomato pinworm, Tuta absoluta
(Springer Science and Business Media Deutschland GmbH, 2021) Rajendran Dhanapal; Rajendra Nath Singh; Mahadevan Raghuraman; Muthugounder Mohan; Kesavan Subaharan; Manivannan Hemavathi
Mirid bug, Nesidiocoris tenuis is a voracious predatory bug that is spontaneously present in horticultural crops. Recently, it has been reported and practiced as a biocontrol agent against several insect pests. In the present study, we have evaluated mirid bug’s predatory potential against Tuta absoluta developmental stages. Eggs, 1st, 2nd and 3rd larval instars of T. absoluta were seemingly the most preferred by all feeding stages of the mirid bugs. The 4th larval instar and pupae of T. absoluta were not pre-selected to feed during any stage of N. tenuis. As the T. absoluta immature stages grew in size, their total prey consumption decreased. The olfactory bioassay was performed for the adults of N. tenuis against tomato plants infested with various developmental stages of T. absoluta, using a Y-tube olfactometer. The results revealed that the early stages of T. absoluta, especially eggs emit volatiles to allure the N. tenuis adults. These outcomes enriched the resources for mass rearing of N. tenuis and their efficacy in the field, which will undoubtedly aid the farmers in the prevention of crop damage due to pests and control the tomato pinworm. © 2021, Institute of Zoology, Slovak Academy of Sciences.
First record of Texas citrus mite, Eutetranychus banksi (McGregor) infesting neem (Azadirachta indica A. Juss) from India
(Malhotra Publishing House, 2021) Ramesh Singh Yadav; Gopal Prasad Painkra; Dharmpal Kerketta; Dharmendra Kumar; Mahadevan Raghuraman
During the present investigation a series of samples of an unusual spider mite were collected from the Neem, Azadirachta indica A. Juss in the Zamania, Ghazipur of Uttar Pradesh, India. The collected mite fauna was identified as the Texas citrus mite, Eutetranychus banksi (McGregor) (Trombidiformes: Tetranychidae) causing notable harms to the overall plant in the early stage of this naturally grown early aged plants in the field condition during the cold winter season of 2018-2020. It has emerged as a new pest of neem, Azadirachta indica A. Juss plants in India and first time reported for the country during present study © 2021, Journal of Entomological Research.All Rights Reserved.
Occurrence, Distribution, Damage Potential, and Farmers’ Perception on Fall Armyworm, Spodoptera frugiperda (J.E. Smith): Evidence from the Eastern Himalayan Region
(MDPI, 2023) Satyapriya Singh; Mahadevan Raghuraman; Manikyanahalli Chandrashekara Keerthi; Anup Das; Saswat Kumar Kar; Biswajit Das; Hidangmayum Lembisana Devi; Sunil Kumar Sunani; Manas Ranjan Sahoo; Ryan Casini; Hosam O. Elansary; Gobinda Chandra Acharya
The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), is a polyphagous non-native pest identified as a serious threat to crop production and food security globally, including in India. Its unintentional introduction and quick coverage in large areas is a serious concern to millions of farmers in the eastern Himalayan region. However, detailed understanding of farmers’ perceptions and the biological attributes associated with the meteorological factors for FAW is limited. The present investigation, which aimed to create baseline data on this pest, concurs with the idea that the FAW is widely dispersed throughout the maize ecosystems of Tripura, with an average infestation rate of 21.33 percent. The severity ranged from 0 to 1.40, with an average leaf damage score of 1 on a 0–4 categorical scale. The findings indicate that pheromone trap catch was significantly correlated with the evaporation rate as other meteorological factors influenced variably. The biological attributes imply that the life cycle was completed in 32.82 ± 0.08 days, with a high fecundity potential (1068.57 ± 4.35 numbers) in controlled conditions (25 ± 1 °C, 70 ± 5% RH). Indigenous natural enemies, such as entomopathogens, spiders, and wasps, were found to be the first defence against this invasive pest. A minority of the population (17.51%) was aware of the incidence of FAW. Furthermore, respondents’ socio-demographic variables were associated significantly with FAW status. This is the first scientific report from the eastern Himalayan region about farmers’ knowledge and awareness of the invasiveness of FAW. This finding enumerates a detailed understanding of FAW from diverse perspectives. Further, the concerted data provide an important baseline that could help the development of holistic management strategies for FAW. © 2023 by the authors.