Emerging threat of carob moth (Ectomyelois ceratoniae Zeller) in Turkish walnut orchards: Evidence for economic damage and implications for integrated pest management

Abstract

Walnut (Juglans regia L.) is an important nut crop recognized for its nutritional and economic value, with Türkiye ranked among the top four producers globally. Infestation of Lepidopteran pests significantly threaten walnut yield and quality. Pest management strategies and official national recommendations in Türkiye have traditionally concentrated on codling moth (Cydia pomonella L.) as a major pest of walnut. Carob moth (Ectomyelois ceratoniae Zeller) is a polyphagous pest, causing damage to pomegranate and citrus orchards. However, it has been generally overlooked by national walnut integrated pest management strategies in Türkiye. This two-year field study (2022–2023) evaluated infestation patterns, damage severity, and economic losses caused by codling and carob moths in four walnut orchards in Çanakkale Province, Türkiye. Weekly monitoring, fallen fruit culturing, and harvest assessments indicated a distinct phenological differentiation between the studied moths. Infestations of codling moth peaked during early to mid-season, whereas carob moth infestations dominated later in the season. Carob moth surprisingly caused fruit damage and quality losses equivalent to codling moth, i.e., US$3500 to US$3900 ha⁻¹. These results indicate that current management strategies, which neglect carob moth, are inadequate for protecting walnuts during late-season pest infestations. We recommend revising national pest management strategies to include monitoring and control actions for carob moth. It is essential to use integrated strategies that include cultural sanitation, pheromone trapping, and biological control to reduce losses and maintain superior walnut production in Türkiye.