Evaluating secondary metabolites of dry and semi-dry dates on the fitness traits of Plodia interpunctella Hübner in storage conditions

Abstract

Date, Phoenix dactylifera L., is a nutritious fruit that provides dietary benefits and raw materials for the food industry, containing simple sugars, proteins, fats, phenols, fiber, and antioxidants. The Indianmeal moth, Plodia interpunctella Hübner, is a polyphagous pest that reduces product quality, increases costs, and generates customer complaints. This study evaluated the fitness traits of P. interpunctella in response to seven date cultivars: four dry (Daglat Nour, Deyri, Tori, and Zahedi) and three semi-dry (Estamaran, Khasouee, and Pyaram) under storage conditions to identify resistant cultivars. Khasouee exhibited the highest moisture content compared to Daglat Nour. It also had the highest total phenol and flavonoid levels, while Daglat Nour had the lowest. Pre-adult periods for both male and female moths were longest on Khasouee and shortest on Daglat Nour. The oviposition period was significantly longer on Daglat Nour than on Khasouee and Pyaram. Fecundity differed significantly, with increased rates on Daglat Nour and decreased rates on Pyaram. Moths fed on Daglat Nour and Pyaram showed the highest and latest net reproductive rates (R₀) and intrinsic rate of increase (r), respectively. R₀ and r values exhibited a strong negative correlation with the physical and secondary metabolites of the date cultivars. Thus, Daglat Nour is highly susceptible to the moth, whereas Estamaran, Khasouee, and Pyaram demonstrate resistance, indicating the importance of semi-dry date resistance for pest control in stored crops.