Environ Exp Biol (2020) 18: 283–289

Efficacy of different extracts of Allium chinense bulb against Sitotroga cerealella infestation in stored paddy grain, Oryza sativa

Abstract

Stored grain pest Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae) is considered as one of the most destructive pests of cereal grains. The study aim was to develop methods to suppress moth emergence and reduce the weight loss of paddy grain (Oryza sativa L.) in storage using bulb extracts of Allium chinense G.Don from solvents of varying polarity (hexane, petroleum ether, chloroform, methanol, ethanol, and water). The results showed that all of the tested extracts had significant effect on the developmental period and moth emergence. The petroleum ether extract with LC₅₀ value of 0.39% (0.16 to 0.62%) and ethanol extract with LC₅₀ of 0.45% (0.21 to 0.68%) exhibited remarkable activity against S. cerealella, as no moth emergence was observed when applied at 2% concentration. For the chloroform extract, 2% concentration showed the highest inhibition on the developmental stage, where moths emerged at 42.50 days, compared to 28.75 days in the control. The weight loss of paddy was best controlled with 2% ethanol extract (2.55%); the highest loss was recorded in paddy treated with water extract. The present study concludes that petroleum ether and ethanol extract of bulbs of A. chinense have potential use in integrated pest management of S. cerealella for post-harvest protection of paddy, considering availability and easy propagation of the plant, and environmental friendliness.