Rhynocoris fuscipes (Fab.) is a reduviid predator found in many agro-ecosystems that predates on different types of insect pest including Spodoptera litura and Helicoverpa armigera. In the study, the description and characterization of the mouthpart morphology and venomous saliva have been studied. Furthermore, the impact of the venomous saliva has been evaluated on S. litura and H. armigera by using the microinjection bioassay and oral toxicity bioassay, anti-agglutination, anti-spreading and cytolytic effects. Other than the zootoxic nature of the venomous saliva of R. fuscipes, the mammalian toxicity has been evaluated on the Swiss Albino mice.