Impact of modified atmospheres enriched with carbon dioxide on the survival, biological, and physiological aspects of Aleuroglyphus ovatus (Troupeau, 1878)

Abstract

Aleuroglyphus ovatus (Troupeau, 1878), a prevalent mite within stored products, inflicts substantial economic and health risks. The use of fumigants and grain protectants as methods of stored grain pest management had resulted in resistance and environmental concerns, necessitating alternative strategies. This study explored the toxicity of modified atmospheres composed of CO2, as an environmentally friendly, residue-free, and viable disinfestation alternative. The mortality of A. ovatus increased significantly with an increase in either CO2 concentration or exposure duration. Complete adult mortality was recorded after 72 h of treatment with 95% CO2. The calculated LT50 value was 30.52 h under 35% CO2, and it decreased to 11.78 h under 95% CO2. Additionally, CO2 exposure led to changes in the activity of antioxidant and detoxification enzymes in A. ovatus, indicating its physiological adaptation mechanisms under varying CO2 concentrations and the impact of these changes on development and reproductive capacity. Enzymatic assays revealed a concentration-dependent decrease in superoxide dismutase activity and an increase in catalase activity. The detoxification enzymes, glutathione S-transferase, and carboxylesterase demonstrated adaptive upregulation. The development of A. ovatus was delayed, and its reproductive capacity was reduced under CO2 stress. Population parameters, including the net reproductive rate (R0) and intrinsic rate of increase (rm) were all significantly reduced under CO2 stress, with 35% CO2 showing the severer impact. The study concludes that CO2 can be an effective tool for pest management in stored products, with 35% CO2 showing potential as a more economical option for A. ovatus extermination.