Chlorantraniliprole: bioactivation in coffee seedlings and control of resistant Leucoptera coffeella populations.

BACKGROUND: The diamide chlorantraniliprole stands out for its high performance in controlling agricultural pests, with high selectivity and reduced environmental impact. In coffee cultivation, this insecticide has been widely employed for the management of the coffee leaf miner (Leucoptera coffeella Guérin-Méneville, 1842). However, intensive use has favored the selection of resistant populations, compromising control efficacy and intensifying biotic stress in plants. This study aimed to evaluate the morphophysiological effects of chlorantraniliprole on coffee seedlings (Coffea arabica L., cv. IAC144-Catuaí Vermelho) infested by L. coffeella populations with different resistance levels. A total of 12 treatments (six insecticide concentrations applied to two populations: susceptible and resistant) with 12 replicates were conducted. Physiological assessments (transpiration, stomatal conductance, assimilation, and internal carbon dioxide concentration) were performed at 0, 20, and 105 days after application (DAA). Growth traits (number of leaves, plant height, stem diameter, leaf area, and biomass), along with Soil Plant Analysis Development (SPAD) index and leaf miner infestation index, were quantified at 0, 20, 40, 60, 80, and 105 DAA. RESULTS: Indicated a positive effect of chlorantraniliprole on the number of leaves, leaf area, and both fresh and dry shoot biomass in plants infested with the susceptible population. In plants exposed to the resistant population, increasing insecticide concentration and plant age promoted stem diameter growth, which may represent a compensatory response to continuous stress caused by persistent infestation. CONCLUSION: Besides being effective in controlling susceptible L. coffeella, chlorantraniliprole may also act as a plant bioactivator, representing a strategic tool in integrated pest management. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.