Introduction: Bactericera cockerelli (Sulc) and Bemisia tabaci are phytophagous insects that cause significant losses in horticultural crops. The use of plant extracts represents a sustainable alternative for their control.
Objective: To evaluate the in vitro bioinsecticidal effect of polar extracts of Heliopsis longipes, Azadirachta indica and Ricinus communis at different concentrations on the mortality of nymphs of B. cockerelli and B. tabaci.
Methodology: Phytochemical analyses were performed on polar root extracts of H. longipes and seeds of A. indica and R. communis. Seven concentrations of each plant extract (0, 50, 60, 70, 80, 90, and 100 mg∙mL-1) were evaluated under a complete factorial design. In vitro mortality of B. tabaci and B. cockerelli was determined
from the median lethal concentration (LC50) by immersion.
Results: Extracts of R. communis and H. longipes showed the highest in vitro toxicity against nymphs of B. tabaci and B. cockerelli, respectively.
Study limitations: The bioassay was performed only with plant extracts; the insecticidal activity of its major compounds needs to be evaluated and possible mechanisms of action elucidated.
Originality: Few studies report the bioinsecticidal effect of two of the extracts evaluated in this research.
Conclusions: Polar extracts of R. communis and H. longipes could be an alternative to formulate bioinsecticide products for the control and management of B. tabaci and B. cockerelli.