The first cases of diamide-resistant Tuta absoluta (Meyrick) and the alternation of the insecticidal modes of action as a key IPM practice for sustainable control

Abstract: This paper reports on the sensitivity monitoring executed by DuPont and collaborators in Italy, Spain, Greece since 2009 in order to detect possible sensitivity shifts of T. absoluta from baseline sensitivity to the diamide insecticide chlorantraniliprole (MoA group 28). The results of the 2014 bioassays revealed the first cases of T. absoluta resistance to diamide insecticides in South-East Sicily. The resistant strains feature high resistance ratios vs. sensitive strains. Unpublished molecular and inheritance studies suggest target-site mutation as the likely resistance mechanism. On-farm interviews have highlighted consistent and widespread abuse of chlorantraniliprole-based products over the last 5-6 years, with growers not respecting product label directions for use and neglecting good agricultural practices including IPM. In this paper, potential integrated control strategies are discussed, aiming to prevent further directional selection of resistance alleles via the adoption of stringent IPM strategies inclusive of reasoned IRM/MoA alternation programmes.