Chemical residues and bioactivity of tebufenozide applied to apple foliage

摘要: Tebufenozide, an insect growth regulator that acts as ecdysone agonist, was applied at recommended label rate to apple trees in August 1997 and May 1998. Foliar residues were determined by high-performance liquid chromatography from samples collected 2, 24, 48 96 h post-spray, weekly intervals thereafter for 9 weeks 11 Foliage sampled the same times used bioassays determine residual toxicity first-instar obliquebanded leafrollers, Choristoneura rosaceana (Harris). Residue decay followed first-order kinetics both years, with half-life of 36.3 days 7.2 Estimates time needed reduce bioactivity 50% 18.7 The accuracy equations describing tebufenozide over not improved using degree-day accumulations independent variable.