Influence of Some Fruit Traits on Codling Moth (Cydia pomonella L.) Preference among Apple Varieties in Two Contrasted Climatic Conditions

Codling moth, Cydia pomonella L., is a major pest of pome fruits and walnuts worldwide. Screening the susceptibility of apple varieties to C. pomonella infestation is an important step to develop a sustainable management program against this pest. Therefore, the present study aimed to explore potential correlations between pest damage and several physical (firmness, weight, and diameter), chemical (pH, SSC, and TA), and biochemical (polyphenols) fruit properties collected from two sites with distinctively twelve and seven commercial apple varieties. The study was conducted in two distinct Moroccan regions to highlight whether the traits influencing the insect's preference could be similar for different varieties under contrasted climates. In both regions, results revealed that the pest damage varied significantly across apple varieties as well as between observation dates. The late and medium maturing varieties had similar damage patterns and were heavily attacked compared to early maturing ones. The preferred varieties were Galaxy Gala, Obro Gala, Golden Smoothee, Black Staymen, and Idared, while the least preferred ones were Anna, Dorsett, and Stark Delicious. Some physical and chemical fruit properties seemed to be associated with the insect behavior, in particular, firmness and pH were positively correlated to pest damage. Moreover, the research suggested that infestations might be influenced by diameter, weight, and polyphenol content of fruits.