The role of amiloride in the labellar responses to various salt stimuli in the blowfly Protophormia terraenovae was studied with the aim of ascertaining whether salt reception is mediated by an amiloride-sensitive cation conductance. Results indicate that, unlike the case of NaCl, KCl sensitivity is inhibited by amiloride. W-7 (a calmodulin antagonist, involved in the Ca2+ cascade) strongly inhibits the chemosensillar response to both NaCl and KCl. Implications of transduction mechanisms for the 'salt' and 'water' chemoreceptors are discussed