Risk assessment, cross-resistance, biochemical mechanism and fitness cost of tetraniliprole resistance in the tomato pinworm Tutaabsoluta

Abstract

Tuta absoluta is one of the most devastating and invasive insect pests throughout the world. It feeds on numerous solanaceous plant species and has evolved resistance to various types of popular chemical agents. Tetraniliprole is a novel diamide chemical agent that acts as a modulator of the ryanodine receptor, and it has been considered as a promising insecticide against T. absoluta. In this study, we subjected a T. absoluta strain to 17 generations of continuous selection with tetraniliprole in the lab. The resulting tetraniliprole-selected T. absoluta strain (YN-Tet) exhibited a 12.9-fold higher resistance to tetraniliprole compared with a susceptible strain (YN–S), and the realized heritability (h2) was estimated to be 0.1437. The YN-Tet strain exhibited a low level of cross-resistance to chlorantraniliprole and significantly higher cytochrome P450 monooxygenase activity. There was a fitness cost of tetraniliprole resistance in the YN-Tet strain, which had a relative fitness of 0.83 compared with the YN-S strain and a significantly lower fecundity per female. These results enhance our knowledge of the risk and mechanism of tetraniliprole resistance, enabling future optimization of resistance management strategies.