[1] Crops in India on which it has been found feeding on pests include sugarcane, pigeon pea, cardamom, cotton, tea, and peanuts.

Most notably among these adaptations is their extra-oral digestion feeding mechanism, as well as a three-segmented rostrum, or barb, armed with a number of hair-like mechanical and chemical sensors, used not only to sense and determine the suitability of their prey, but also to deliver venomous saliva to paralyse their victims.

[3] Unique to R. marginatus is their accessory salivary glands which function as water recapturing organs that recirculate water from the body to keep a steady flow of watery saliva going as they feed, helping the predator to flush out predigested food from the body of its prey.

[4] Rhynocoris marginatus as one of the largest and most easily recognized assassin bugs found in semi-arid, scrub jungle, tropical forests and agroecosystems.

Different life stages have different food preferences, but in general, when offered various choices, the larva of the tobacco cutworm Spodoptera litura (a moth larva) was the first choice, followed by Helicoverpa armigera, Aproaerema modicella and Amsacta albistriga in that order.