Variation in the susceptibility to insecticides in rice leaffolder, Cnaphalocrocis medinalis (Guenee) populations from Kerala, India
Abstract
The rice leaf folder, Cnaphalocrocis medinalis, is a major pest causing substantial yield losses in key rice-producing states of India, including Kerala. Despite widespread insecticide use, there is a lack of comprehensive data on the susceptibility of C. medinalis populations to commonly used insecticides in the region. This study evaluates the susceptibility status of C. medinalis to ten commonly used insecticides across five major rice-growing agroecological units in Kerala: AEU 23 (Palakkad Eastern Plains), AEU 4 (Kuttanad), AEU 3 (Onattukara Sandy Plains), AEU 6 (Kole Lands), and AEU 20 (Wayanad Central Plateau). Bioassay results indicated that the population from Wayanad remained susceptible to all tested insecticides, while other field populations exhibited high resistance to quinalphos (133.24-fold to 611.37-fold) and lambdacyhalothrin (170.73-fold to 763.66-fold). Moderate to high resistance was observed against carbosulfan (25.40-fold to 347.96-fold), chlorantraniliprole (71.75-fold to 1089.63-fold), and flubendiamide (67.91-fold to 1572.64-fold). Correlogram analysis highlighted acephate as a viable option for management, as it showed no cross-resistance with other insecticides. Cartap and emamectin benzoate were detected as potential alternatives for managing diamide-resistant populations. Thehigh resistance to quinalphos and carbosulfan, and their correlation with multiple insecticides, indicate the need to temporarilydiscontinue their use for C. medinalis management in Kerala. This study provides the first comprehensive assessment of insecticide resistance in C. medinalis populations in Kerala and establishes crucial LC50 benchmarks for future resistance monitoring and management strategies.
Downloads
Published
How to Cite
Issue
Section
License
Copyright © 2001-11 Kerala Agricultural University. Some rights reserved. This journal and the individual contributions contained in it are protected under copyright by the Kerala Agricultural University and the following terms and conditions apply to their use; Photocopying Single photocopies of single articles may be made for personal use as allowed by national copyright laws. Permission of the publisher and payment of a fee is required for all other photocopying including multiple or systematic copying, copying for advertising or promotional purposes, resale, and all forms of document delivery. Permission may be sought directly from the Editor, Journal of Tropical Agriculture, Department of Agronomy, College of Horticulture,, Kerala Agricultural University, KAU PO, Thrissur 680 656, Kerala, India. (Phone: +91-487-2438325; Fax +91-487-2371040; E-mail: editor.jta@kau.in. Derivative works Subscribers may reproduce tables of contents or prepare lists of articles including abstracts for internal circulation within their institution. Permission of the Publisher is required for resale or distribution outside the institution. Permission of the Publisher is required for all other derivative works, including compilations and translations. Notice No responsibility is assumed by the Publisher for any injury and/or damage to persons or property as a matter of products, liability, negligence, or otherwise, or from any use of any methods, products, instructions or ideas contained in the material herein.