Abstract: To utilize a plant-based insecticide, the study of biosafety of botanical insecticide to polyphagous natural enemies are imperative. A laboratory trial was conducted to investigate the biosafety of Tephrosia purpurea stem-based formulation (Telp 3% EC) against three reduviid predators such as, Rhynocoris fuscipes, Rhynocoris marginatus and Rhynocoris longifrons adults using Y-shaped olfactometer considering olfactory response as a tool. Telp 3% EC was impregnated in Whatman No. 1 filter paper, Bt cotton leaves (BT bunny) and groundnut leaves (TMV 4). The Access Proportion Index (API) was calculated in different time intervals like 20, 40 and 60 min. Olfactory response results revealed that impregnation of Telp 3% EC in Bt cotton leaves does not deter Rhynocoris longifrons olfactory response whereas, groundnut leaves deter both Rhynocoris fuscipes and Rhynocoris marginatus olfactory response. It has been concluded from the results that Telp 3% EC can be incorporated along with reduviid predators in BT cotton pest management. However, detailed studies are necessary to confirm the observation.