GC-MS analysis of metabolite alteration in tea leaves and pest guts following infestation by red spider mite, Oligonychus coffeae (Nietner) (Acari: Tetranychidae) and tea mosquito bug, Helopeltis theivora Waterhouse (Hemiptera: Miridae)

Abstract Background The tea plant, Camellia sinensis (L.) Kuntze, is the source of the world’s second most consumed beverage. Its leaves are severely damaged by two major sucking pests: the red spider mite, Oligonychus coffeae (Nietner) (Acari: Tetranychidae) and the tea mosquito bug, Helopeltis theivora Waterhouse (Hemiptera: Miridae), leading to significant crop and quality loss. This study investigates the metabolomic changes in tea leaves following infestation by these pests and analyzes the corresponding metabolites found in the pests’ guts using GC-MS. Results The gut contents of both pests were predominantly composed of fatty acid derivatives. Key compounds identified included 2-oxabicyclo[2.2.2]octan-3-one, myristic acid, caffeine, oleic acid, and palmitic acid. Comparative analysis revealed that twelve unique metabolites are present in the guts of both the red spider mite and the tea mosquito bug. Conclusion The alteration (increase, decrease, or de novo appearance) of these metabolites suggests that the pests’ enzymatic or microbial gut systems actively modify plant-derived compounds with insecticidal properties. For the first time in analyses of tea and insects, large quantities of 2-oxabicyclo[2.2.2]octan-3-one was found in the pests’ guts. However, because the pests feed on a variety of different plants, it may be a case of contamination, and further targeted analyses are required to confirm its origin and biological relevance.