The tomato borer Tuta absoluta : insecticide resistance and control failure.

Abstract The tomato borer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) evolved from a local South American concern to become a worldwide threat in tomato production less than three decades after initially spreading throughout South America, and eventually through Europe, North Africa and Middle East with an increased likelihood of invading Asia. Despite the studies performed thus far on this invasive species, management is difficult and insecticide is a major component of control. As a result, insecticide resistance has led to insecticide control failure in South America, where farmers have heavily relied on insecticide against this pest species since the 1980s. Reports from Chile, Argentina and, in particular, Brazil suggest that insecticide resistance evolves quickly in this species as a direct response to insecticide use (and overuse). Insecticide replacement for controlling the tomato borer typically leads to rapid changes in the patterns of insecticide resistance for this species. However, the resistance frequency for previously used compounds, such as pyrethroids, remains and likely results in a faster increase in resistance with selection, even in areas where this pest species was recently introduced. Recent genetic studies on the tomato borer suggest that insecticide resistance and control failure for this species in South America are also concerns elsewhere because newly introduced strains carry insecticide-resistance genes at a relatively high frequency even without local selection at the site of introduction.