author(s)
Rudra N Borkakati, Venkatesh MR, DK Saikia and Sasanka S Bora

abstract
Insects feed on almost every kind of organic matter irrespective of living or dead. Moreover, most insects are specific to their food selections and restrict themselves within some particular kind of food. Obviously, insect-plant interactions are also of crucial importance in selection, finding and recognition of host. Recognition of host plants, prey and cell sap by different herbivores or natural enemies or blood sucking insects respectively is important for gathering energy to complete their life cycle. Recognition of food by insects involves behavioural responses to food, sensory mechanisms and perception of odours released by host. Visual, olfactory and gustatory cues act as a sensory system; and experience-learning and orientation mechanism acts as a behavioral mechanism for an insect to recognize their source of food. Moreover, semiochemicals also plays a vital role in food location and recognition by insects in the form of kairomones. On the other hand, thermal stimuli, CO₂ and odours are acts as cues for recognition by blood sucking insects.