Britannica Sources used in this answer

How do insect taste receptor cells detect sugars amino acids salts and feeding deterrents?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

A pine grosbeak with pink and gray plumage perches on a branch, eating red berries among autumn foliage. — Chemoreception Animals, such as this pine grosbeak, use chemoreception to respond to chemicals that can be tasted and smelled in their environments. Many of these chemicals affect behaviors such as food preference and defense.

In insects, taste detection occurs primarily through sensilla—hairlike cuticular structures located on feeding appendages, legs, and sometimes other body parts. These structures contain the dendrites of receptor cells, which are exposed to the environment via small pores.1

Detection Mechanisms

Insects typically possess four taste receptor cells per hair, each specialized to respond to specific chemical categories, including sugars, amino acids, inorganic salts, and feeding deterrents (often bitter compounds). Unlike vertebrates, these receptor cells have axons that extend directly to the central nervous system without intervening synapses.1

Receptor Proteins: The ability to distinguish between different compounds is believed to reflect the presence of specific receptor proteins in the cell membranes. For example, some insects possess distinct proteins for different sugars, such as one for glucose and sucrose and another for fructose.1
Perireceptor Events: Because insects can perceive chemicals on dry surfaces, molecules are likely transported to the nerve endings by carrier proteins within the material covering the pores.1
Specificity: While many cells respond to limited ranges of compounds, some insects have evolved highly specialized receptors, such as those tuned to host-specific chemicals like glucosinolates in crucifer-feeding species.1