Gas-liquid chromatography analysis of phospholipids and triglycerides in Plodia interpunctella (Hübner) larvae: Effect of different diets

The Indian meal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) is an important insect pest on a wide range of stored food diets. This study employed gas-liquid chromatography to investigate the influence of different diets (pistachio, raisins, and walnuts) on the composition of phospholipids and triglycerides in fifth instar larvae of P. interpunctella. The fatty acid profiles of the larvae revealed seven essential fatty acids including myristic, palmitic, palmitoleic, stearic, oleic, linoleic, and linolenic acids. The fatty acid composition of larvae-extracted phospholipids and triglycerides also varied according to the diet type. In terms of phospholipids, the highest concentration of myristic acid was observed in larvae fed walnut. Raisins exhibited the highest levels of palmitoleic and oleic acid, while pistachio demonstrated the highest concentration of linoleic acid. However, no significant differences were observed among the treatments concerning palmitic acid, stearic acid, and linolenic acid. Regarding triglycerides, no significant differences were found among the treatments in terms of myrisitc acid and oleic acid. However, the raisins treatment displayed the highest amount of palmitoleic acid, while both pistachio and walnut treatments exhibited the highest levels of linoleic acid. Additionally, the concentration of linolenic acid in larvae fed walnut was higher than other test diets. These findings provide valuable insights into the fatty acid composition of P. interpunctella fed different diets. Such knowledge can be utilized in developing pest management strategies, as the manipulation of fatty acid profiles in insects’ diet could potentially impact their growth, development, and fitness.