Bioefficacy and phytotoxicity study of tolfenpyrad 15% EC, a novel pyrazole insecticide for management of Plutella xylostella (L.) and Brevicoryne brassicae L. infesting cabbage and its effect on coccinellid predator

Tolfenpyrad 15% EC was evaluated at Regional Research Station (Hill Zone) of Uttar Banga Krishi Viswavidyalaya, Kalimpong, West Bengal, India at three dose levels (100, 125 and 150 g a.i. ha⁻¹) against Diamond back moth (DBM) and aphid infesting cabbage during 2014–15 and 2015–16. Seven treatments viz., tolfenpyrad 15 EC @ 100, 125 and 150 g a.i. ha⁻¹, Keefun (market sample of tolfenpyrad 15 EC) @ 150 g a.i. ha⁻¹, chlorpyriphos 20% EC @ 400 g a.i. ha⁻¹, chlorfenapyr (lepido) 10% SC @ 75 g a.i. ha⁻¹ along with one untreated control were evaluated under field condition. Tolfenpyrad @ 300 g a.i. ha⁻¹ was also tested for phytotoxicity study only. Application of tolfenpyrad (T3) @ 150 g a.i. ha⁻¹ recorded the lowest mean population of aphid and DBM with maximum yield (27.78 t ha⁻¹) followed by Keefun (market sample of tolfenpyrad 15 EC) @ 150 g a.i. ha⁻¹. Among the treatments, chlorfenapyr 10% SC (lepido) @ 75 g a.i. ha⁻¹ proved to be the safest insecticide with the highest population of C. septempunctata during the study. Tolfenpyrad did not produce any phytotoxicity symptoms on cabbage at higher dose of 300 g a.i. ha⁻¹.