Abstract: Many insects possess sensitive taste perception systems which play crucial roles in the processes of food selection, mating, and oviposition. The mechanism of taste perception is less studied compared to that of olfaction perception in insects. Most of the traditional taste studies are about the morphology and electrophysiology of gustatory sensilla, and behaviour. With the development of techniques on insect molecular genetics, bioinformatics and neurobiology in current years, taste perception mechanisms in insects have been better understood mainly in the following two aspects: (1) Insect gustatory receptor proteins (Grs): putative Grs of many insect species have been identified by bioinformatics, and the number and the protein sequences of Grs are extraordinarily divergent among different species of insects. In general, the Grs can be classified into phagostimulatory receptors and deterrent receptors based on the corresponding ligands. (2) Projections of gustatory sensory neurons on the central nervous system and neural coding mechanisms:  projection of gustatory sensory neurons to different regions of the suboesophageal ganglion and the tritocerebrum of brain in insects has been investigated. This article reviews the research advances concerning basic characteristics of gustatory sensilla and gustatory sensory neurons, evolution, expression and function of Grs, projections of gustatory sensory neurons and plasticity of taste in insects.

Key words: Insects, taste perception, gustatory sensilla, gustatory receptors, neuron projections, taste coding