Expression of cato^Scer\UAS.cGa driven by Scer\GAL4^sca-109-68 directs the formation of ectopic chordotonal organs when expressed strongly. These sensilla tend to be in small poorly formed clusters of chordotonal organs. The scolopale structures are poorly differentiated and often stained inappropriately with neuronal markers. Ectopic macrochaetae are formed only under weak misexpression of cato^Scer\UAS.cGa. They are usually deformed. Misexpression of cato^Scer\UAS.cGa driven by Scer\GAL4^h-1J3 results in expansion of lateral chordotonal organ clusters (usually 5-7 neurons instead of 5). There are organisational and dentritic abnormalities in the chordotonal neurons.