Rhythmic biosynthesis of sex pheromone modulates the calling and mating behaviors of Tuta absoluta (Lepidoptera: Gelechiidae)

Abstract

Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a significant global pest of tomato. Although sex pheromones serve as effective biological control tools, their utilization remains inefficient due to a limited understanding of the circadian rhythms of courtship and mating. This study details a six-step “morning flight–mating” behavioral sequence in T. absoluta: (1) resting, (2) preparation for morning flight, (3) morning flight, (4) courtship, (5) mating, and (6) post-mating cessation. Laboratory observations revealed that their rhythmic behavior occurred between 05:30 and 08:00, with a pronounced peak from 05:30 to 06:30, and high population densities negatively impacted mating success rates. Field experiments corroborated these laboratory observations. Furthermore, the synchronized synthesis and release of major and minor sex pheromone components aligned with the timing of calling and mating behavior. These findings suggest that the “morning flight–mating” rhythm is mediated by the pheromone release cycle. Our results offer a basis for optimizing the timing of pheromone-based control techniques, such as mating disruption and mass trapping, to enhance the efficiency and reduce the cost of pest control.