Insecticidal activity and repellent potential of ocimum gratissimum on tribolium castaneum

Background: Using botanicals for pest control has become very popular in recent years in sub-Saharan Africa and other parts of the world. These botanicals are recognized to offer protection against insect pests thanks to the natural components inherent in them. Some of these chemicals may work independently or in concert to create a desired result that lead to health challenge. Objectives: This study was aimed at evaluating the toxicity and repellent potential of Ocimum gratissimum on Tribolium castaneum. Methodology: The different concentrations 20% (200 mg/mL), 10% (100 mg/mL), 5% (50 mg/mL), 2.5% (25 mg/mL), and 1.25% (12.5mg/mL) of the oil extracts including control with acetone only were selected and tested to determine the LD50 value and LD90 value. Repellent activity contained in the essential oil was done using standard method. Result: Mortality increased in accordance with increase in concentration of O. gratissimum. The highest and lowest doses of O. gratissimum, 200 mg/ml and 12.5 mg/ml (P<0.05, P=0.009), caused mortalities of 90% and 43.3% respectively. The log-probit regression analysis showed that the LD50 and LD90 for this plant extract were 18.60 mg/mL and 175.99 mg/mL respectively. Conclusion: The present study has evidently shown that O.gratissimum oil have insecticidal activity. O.gratissimum oil extract also serve as good toxicant and repellent agents in the treatment of Tribolium castaneum during storage.