Efficacy of different plant-derived smoke on the adult mortality of rice weevil, (Sitophilus oryzae L.) at different time intervals

Abstract

Rice weevil (Sitophilus oryzae L.) is a major pest responsible for substantial losses in stored wheat. Although synthetic pesticides are commonly used to manage these pests, their application poses serious environmental hazards and potential risks to human and animal health. In light of these concerns, the present study was conducted to assess the effectiveness of natural, plant-based smoke treatments in controlling rice weevil infestations in stored wheat. The plant materials tested included neem leaves, eucalyptus leaves, curry leaves, orange peel, bay leaves, and a combination of clove and camphor. These materials were burned to generate smoke, and their impact on adult rice weevil mortality was evaluated. The experiment was carried out in 2024 at the Department of Entomology, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, Uttar Pradesh, using a Completely Randomized Design (CRD). The experiments conducted on the effect of smoke generated by burning plant leaves and extracts on percent mortality of adults of S. oryzae at 24, 48, 72, and 96 h exposure to smoke under airtight conditions resulted in (55.57%) after 48h of exposure to (T6) Clove & Camphor followed by (T1) Neem leaves, (T2) Eucalyptus leaves, (T5) Bay leaves, (T4) Orange peel, (T3) Curry leaves and (T7) Coragen 10 mg smoke. The order of effectiveness of botanicals is ranked as Clove & Camphor>Neem leaves>Eucalyptus>Bay leaves>Orange peel>Curry leaves respectively. Finally, these findings demonstrated that certain plant smokes possess strong insecticidal properties against rice weevils, indicating their potential as effective and eco-friendly alternatives to synthetic fumigants for stored wheat grain protection.