Energy reserves, oxidative stress and development traits of Spodoptera exigua Hubner individuals from cadmium strain

Cadmium as a common environmental stressor may exert highly toxic effects on herbivorous insects. The question was whether possible elevation of an oxidative stress and imbalance of energetic reserves in insects may depend on developmental stage, sex and insect population's multigenerational history of exposure to cadmium. So, the aim of this study was to compare of the development traits, total antioxidant capacity, lipid peroxidation, RSSR to RSH ratio and the concentration of carbohydrates, glycogen, lipids and proteins in whole individuals (larvae or pupae) of Spodoptera exigua originating from two strains: control and selected over 120 generations with sublethal metal concentration (44 Cd mg per dry weight of diet). Generally, the increase of the protein, carbohydrates, glycogen concentration and lipid peroxidation decrease with age of the larvae were found. Revealed cases of a higher mobilisation of carbohydrates and proteins, and changes in total antioxidant capacity or lipid peroxidation, in individuals being under metal exposure, occurred in strain-depended mode. Short-term Cd exposure effect was connected with possible higher engagement of proteins and glycogen in detoxification processes, but also higher concentration of lipid peroxidation. In turn, for long-term Cd exposure effect lower lipids concentration and higher thiols usage seemed to be more specific. (C) 2020 Published by Elsevier Ltd.

Automated summary

Cadmium, a common environmental stressor, can have toxic effects on herbivorous insects, with oxidative stress and energy reserve imbalance influenced by developmental stage, sex, and multigenerational exposure history; Cadmium exposure affects protein, carbohydrate, glycogen, and lipid peroxidation in larvae or pupae; Short-term exposure may involve higher protein and glycogen involvement in detoxification processes, while long-term exposure is linked to lower lipids and increased thiols utilization.