Toxicity of Diafenthiuron 50 WP (NS) to Honey Bees Ranjith M.*, Krishnamoorthy S.V., Kuttalam S., Bajya D. R.1 Tamil Nadu Agricultural University, Coimbatore, 641003 1Institute of Pesticide Formulation Technology, Gurgaon, 122016 *Email: entoranjith@gmail.com
Online published on 31 August, 2017. Abstract A laboratory study was carried out at the toxicology laboratory, Tamil Nadu Agricultural University to evaluate the safety of diafenthiuron (NS) 50 WP to honey bees. Its four doses viz., 200, 300, 400 and 800 g a.i. ha−1 along with the current formulation (ES) at 400 g a.i. ha−1 with standard checks quinalphos 25 EC at 150 g a.i. ha−1 and phenthoate 50 EC at 100 g a.i. ha−1 were included. Diafenthiuron 50 WP (NS) at 800 g a.i. ha−1 was exceptionally harmful to Apis cerana indica F., Apis florea F. and Apis dorsata F., but moderately harmful to Trigona iridipennis Smith. The field recommended dose of 400 g a.i. ha−1 was harmless to A. cerana indica, A. florea and A. dorsata with mortality <50%, but slightly harmful to T. iridipennis (mortality >60.00%). The order of toxicity was found to be quinalphos 25 EC > phenthoate 50 EC > diafenthiuron 50 WP (NS) 800 g a.i ha−1 > diafenthiuron 50 WP (ES) 400 g a.i. ha−1 > diafenthiuron 50 WP (NS) 400 g a.i. ha−1 > 300 g a.i. ha−1 > 200 g a.i. ha−1. Top Keywords Diafenthiuron, honey bee, safety, Apis cerana indica, A. florea, A. dorsata, Trigona iridipennis, phenthoate, quinalphos. Top |