Evaluation of Different Botanical Extracts Against Tribolium Castaneum and Sitophilus Oryzae

Abstract

Red flour beetles (Tribolium castaneum) and rice weevils (Sitophilus oryzae) are two important pests that harm stored grains globally. The effectiveness of four essential oils neem (Azadirachta indica), clove (Syzygium aromaticum), garlic (Allium sativum), and eucalyptus (Eucalyptus globulus) against these pests was assessed in a study that took into account the targeted action of botanicals and their reduced environmental impact when compared to synthetic pesticides. Filter paper was treated with 2%, 5%, and 10% concentrations of each essential oil. For the experiment, an extended glass tube with a 1000 ml capacity was utilized. Twenty grams of rice were placed at the ends of the tube, which was divided into three sections. Treated and untreated filter papers were positioned in sections A and C, respectively, while ten newly emerged adults of each pest were released into the center of section B. Mortality and repellency were recorded at 24, 48, and 72 hours post-exposure. The results showed a clear dose and time dependent increase in mortality for both T. castaneum and S. oryzae. Neem extract exhibited the highest toxicity, causing up to 94% mortality in T. castaneum and 89% in S. oryzae at 10% concentration after 72 hours. Clove showed the second-highest activity, with mortality reaching 76% in T. castaneum and 74% in S. oryzae. Garlic caused moderate mortality (36–62%), while eucalyptus was the least effective, with mortality generally not exceeding 42% at the highest concentration. LC₅₀ and LC₆₀ values further confirmed neem as the most potent botanical, followed by clove, garlic, and eucalyptus. Overall, neem demonstrated superior insecticidal performance across mortality, lethal dose values, repellency and grain protection, highlighting its strong potential as a botanical biopesticide