Exploring Heteropanax fragrans (Roxb.) Seem. Essential Oils: Chemical Composition and Insecticidal Activity Against Stored-Product Insects.

Oryzaephilus surinamensis, Lasioderma serricorne, and Tribolium castaneum are globally prevalent stored-product insect pests that cause significant economic losses due to contamination and damage to stored agricultural commodities. Traditional insecticides are harmful to health and the environment. In contrast, plant essential oils (EOs) offer a safer and more environmentally friendly alternative. This study investigates the insecticidal potential of EOs extracted from different parts of Heteropanax fragrans (Roxb.) Seem. against these insects. The EOs were extracted via hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 34 compounds were identified, with β-caryophyllene being the major constituent. The leaf essential oil (HL) showing the highest contact toxicity against L. serricorne (LD50 = 5.26 µg/adult) and T. castaneum (LD50 = 22.26 µg/adult). The branch essential oil (HB) was particularly effective against O. surinamensis (LD50 = 18.41 µg/adult). In terms of repellent activity, HL demonstrated high repellency rates of up to 94% against T. castaneum at the highest concentration (78.63 nL/cm2). These findings highlight the potential of Heteropanax fragrans EOs as eco-friendly botanical insecticides for the sustainable management of stored-product insect pests, offering a safer and more environmentally friendly approach to pest control in agricultural storage.