~ 86 ~ ISSN Print: 2664-844X ISSN Online: 2664-8458 IJAFS 2025; 7(1): 86-88 www.agriculturaljournals.com Received: 19-10-2024 Accepted: 22-11-2024 All author's name and affiliations are given below, after references Corresponding Author: Ravi M Associate Professor (Agricultural Entomology), ICAR – Krishi Vigyan Kendra, Tamil Nadu Agricultural University, Salem, Tamil Nadu, India Efficacy of novel insecticides against castor whitefly, Trialeurodes ricini (Genn) and thrips, Retithrips syriacus (Mayet) Radhakrishnan V, Ravi M, Sowmiya A, Arulprakash R, Allwin L, Vijay S, Vijayaprabhakar A, Karunakaran V, Periyar Ramasamy D, Harisudan C and Baskaran V DOI: https://doi.org/10.33545/2664844X.2025.v7.i1b.241 Abstract Field experiment was carried out at the Entomology Laboratory, Agricultural College and Research Institute, Vazhavachanur, Thiruvannamalai, Tamil Nadu, India during Rabi 2020 and to study the efficacy of insecticides with specific mode of action against thrips and whitefly in castor. The experiments were conducted with completely randomized block design along with ten replications. Minimum mean population of thrips 4.48/plant was recorded after two spraying of Buprofezin 25 SC @ 0.8 ml/lit of water whereas untreated check recorded 39.65 thrips/plant with a mean population reduction of 88.70 per cent over untreated control plot. Similarly, Buprofezin 25 SC @ 0.8 ml/lit recorded a lowest mean population of whitefly as 8.30/plant with a mean population reduction of 87.84 per cent over untreated control followed by Profenophos 50 EC @ 2 ml/lit and Azadirachtin 1% with a mean population reduction of 78.76 and 46.58 per cent respectively over. Keywords: Thrips, castor, buprofezin, profenophos and azadirachtin Introduction Castor, Ricinus communis Linnaeus (Euphorbiaceae) is an important non-edible oilseed crop cultivated in India s mostly under rainfed condition. India ranks first in total castor production (FAO, 2020) [3] with 70% and 87% of world area and production, respectively (Agyenim-Boateng et al., 2018) [1] . The castor production is mainly limited by the sucking pests viz., whitefly, Trialeurodes ricini (Genn) and thrips, Retithrips syriacus (Mayet) in the recent times (Ranganatha et al., 2021 and Ranga et al., 2022) [8, 7] with a yield loss potential up to 40 percent (Karan, 2014, Duraimurugan et al., 2015 and Patel et al., 2015) [5, 2, 6] . Farmer adopting insecticidal application as prime management strategy and apply insecticides having broad spectrum activity results in pest resurgence and also affect environment (Singh et al., 2020) [12] . Thus, the current study was proposed to study the efficacy of certain insecticides with specific mode of action against whitefly and thrips on castor. Materials and Methods Field experiment was conducted in completely randomized block design with ten replications at Agricultural College and Research Institute, Vazhavachanur, Thiruvannamalai, Tamil Nadu, India during Rabi 2020 to study the efficacy of insecticides with specific mode of action against thrips and whitefly. Castor F1 hybrid YRCH 1 seeds were sown at 120 cmx 90 cm and raised as per the package of practices recommended by Tamil Nadu Agricultural University. The insecticides were applied with high volume knapsack sprayer using solid cone nozzle when the insect pest attained the economic threshold. Observations on the incidence of sucking pests viz., thrips and whitefly were recorded on target pests were done on five randomly selected plants per replication before the application of insecticide and 3,7,10 and 14 days after the insecticidal treatment. The incidence of insect pests is expressed as number of insects per plant. The seed yield was recorded at each harvest and pooled. Gross income, net income and International Journal of Agriculture and Food Science 2025; 7(1): 86-88