The Sense Organs and Perception

Abstract

The sense organs or receptors (Carthy and Newell, 1968; Dethier, 1963; Horridge, 1965) are those structures whereby the energy of a stimulus arising outside or, less obviously, within the insect, is transformed into a nervous impulse which, after transmission to one of the central ganglia, usually results in a change in the behaviour of the insect or in the maintenance of some existing activity. Proof that a given organ is a receptor has, in many cases, been obtained by electrical recording of the nervous impulse which follows stimulation but some receptors have been studied only through observations on the insect’s behaviour and occasionally a sensory function has been ascribed solely on the basis of structure and anatomical relations. The connection between a receptor and the effector organs which change or maintain activity is often represented as a relatively simple reflex arc (Fig. 67) though it is probable that even the simplest behavioural act involves the coordination of many variable conducting paths whose functional activity depends on the quality of the stimulus and the physiological state of the receptor and nervous system.