Influence of Larval Diet and Adult Age on the Chemical Composition of Female Pheromone Glands of Copitarsia decolora (Lepidoptera: Noctuidae): Implications for Semiochemical-Based Crop Protection

Copitarsia decolora (Guenée) is a polyphagous pest of significant agricultural importance in the Americas, yet its nutritional and pheromone-related variations remain to be understood. This study evaluated the effects of larval diet and female adult age on life-cycle parameters, fertility, survival, and pheromone gland composition in C. decolora reared on Alstroemeria leaves (primary host), cauliflower florets (secondary host), and an artificial diet. While the overall life-cycle duration was similar among diets, Alstroemeria-fed larvae showed the highest fertility and adult longevity. Diet strongly influenced pheromone gland chemistry, with multivariate and quantitative analyses revealing significant diet- and age-dependent variations in key pheromone components, including (Z)-tetradec-9-enyl acetate (Z9-14:Ac) and (Z)-tetradec-9-en-1-ol (Z9-14:OH). Females reared on Alstroemeria exhibited enhanced pheromone production, whereas artificial diets favored higher alkane accumulation. These findings demonstrate nutritional modulation of pheromone biosynthesis and highlight the importance of diet standardization in insect rearing and semiochemical-based pest management strategies.