Grain protectant behaviour of Artemisia annua and reduction in nutritional damage of wheat flour (Triticum aestivum L.) caused by Tribolium castaneum

Indiscriminate use of fumigants to manage stored grains pests has led to the resistance development in Tribolium castaneum. This undoubtedly increases grain damage. Therefore, deciphering the magnitude of nutritional loss caused by the pest is of utmost importance. This study has focused on the extent of damage of wheat flour caused by T. castaneum and its subsequent management using essential oils of Artemisia annua. A comparison of nutritional indices of wheat flour such as carbohydrate, protein, crude fat content was assessed following the American Association of Cereal Chemists method, wherein infested flour was found to be damaged profoundly. Scanning Electron Microscopic analysis at different magnification has revealed structural distortions and loss of starch globules in damaged grains when compared with the undamaged grains. The flour disc bioassay, used to compare the efficacy of essential oils of A. annua derived with four different solvents, reported significant reduction (P<0.01) in relative growth and consumption rate in treatment sets. Among all, n-hexane derived essential oils were most efficient and induced a feeding deterrence of 94.22%. Moreover, dried leaves of A. annua were was highly effective as antifeedant against the pest. The result concludes that the magnitude of flour damage by Tribolium castaneum is immense hence its control using essential oils of Artemisia annua would provide an eco-friendly alternative to the existing chemical fumigants. Thus, the development of natural pesticides with A. annua would act as a potent postharvest management tool for wheat.