Tuta absoluta arrived in the UK in 2009 and rapidly became the most important pest of tomatoes. An integrated pest management (IPM) strategy offered good control until the 2015 and 2016 growing season, when growers began to experience difficulties. Resistance to spinosad in the UK, one of the controls in the IPM programme, has since been confirmed.
AHDB project PE 032 has trialled a new mating disruption technique that artificially saturates the atmosphere in the glasshouse with a synthetic version of a sex pheromone that is naturally produced by female moths to attract males prior to copulation. As a consequence, males become confused and are unable to find females, so they do not mate.
The mating disruption product Isonet-T was approved for use in the UK at the start of the 2017 growing season, when the trials began. Isonet-T was placed in crops in early January - either one week before or two weeks after the arrival of the tomato plants. Where the placement was delayed by two weeks, a few active T. absoluta mines were seen during the first four weeks of the crop, but none thereafter.
Otherwise, no active mines were found during the following 22 weeks in any of the treatments. By that time, Macrolophus were well established and capable of controlling any subsequent T. absoluta infestation.
Researchers warn that the technique could theoretically lead to female moths that are capable of producing eggs without mating, therefore growers should only use Isonet-T as part of an IPM programme.
Work is now underway at the University of Exeter, funded by AHDB Horticulture, to study the impact of the technique on female moth reproduction.