Expression of Scer\GAL4Or22a.PU>Or46aScer\UAS.B.cRa in an in vivo 'empty neuron' system results in strong response to 4-methylphenol from among a panel of diverse odorants tested using single-sensillum electrophysiology. Further tests with structurally related phenols at lower concentration reveal strongest sensitivity to 2-methylphenol and phenol.