Joint action of botanicals against Helopeltis theivora waterhouse and Oligonychus coffeae nietner

Laboratory experiments to evaluate the combined effect of Chromolaena odorata (Co) and Phlogocanthus thyrsiflorus (Pt) against Oligonychus coffeae and Helopeltis theivora revealed that the methanolic leaf extracts at a combination of 75% LC₅₀Pt + 25% LC₅₀Co and 25% LC₅₀Pt + 75% LC₅₀Co were the most effective against O. coffeae and H. theivora, respectively. They recorded the highest co-toxicity coefficient and co-toxicity factor values of 206.53 and 63.34 and 398.40 and 100.00, respectively revealing potentiation and synergistic effects. A combination of 50% LC₅₀Pt + 50% LC₅₀Co can effectively manage both O. coffeae and H. theivora (76.67% and 100.00% adult mortality, respectively) with the highest co-toxicity coefficient and co-toxicity factors.