Experimental quantification of mating disruption for false codling moth, Thaumatotibia leucotreta (Lepidoptera: Tortricidae), in stone fruit and table grape cultivation

Abstract

Mating disruption is the broadcasting of female pheromones within an agricultural system to interfere with, or decrease, the reproductive potential of the pest insect. Seen as a sustainable, nonchemical management method, it is used in citrus orchards against false codling moth (FCM), Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae). Research to support its efficacy against FCM is limited, especially in stone fruit and table grapes. Previous efforts to quantify mating disruption against FCM have yielded inconsistent results, highlighting the necessity for additional investigation. In the present study, an experimental design that provides reliable results was evaluated. Following their release in a stone fruit orchard and a table grape vineyard, sterile males were recaptured with a trapping grid every 24 h, for five days. Trapping efficiency, trap interference and recaptures of wild and sterile moths were compared. Factors that improved the reliability of results included the use of mark-release-recapture experiments, using a nine-trap layout and a paired control, which ensured that only one variable was changed. Experimental blocks were then either treated with 400 or zero pheromone dispensers/ha. The current study reports the first experimental evidence that mating disruption is an effective control method against FCM in stone fruit and table grapes. Mating disruption was calculated at 86% in stone fruit and 93% in table grapes, with less than the field dose, indicating that mating disruption shows promise as a control technique against FCM, in both stone fruit and table grapes. The present study, therefore, sets a solid foundation for further research into the mechanistic understanding of how the pest is disrupted, as well as into calculating the dosage causing the highest level disruption with the smallest amount of pheromone.