Adults respond normally to sucrose and sodium chloride in a feeding preference test. The threshold of avoidance of quinine is increased compared to wild-type. This phenotype is partially dominant. Homozygous adults show a normal electrophysiological response from the labellar chemoreceptors in response to 100mM NaCl or sucrose.

Taste mutant that affects the fly's responses to attractants and repellents. Insensitive to quinine (C₂₀H₂₄N₂O₂), but shows normal responses to sucrose (C₁₂H₂₂O₁₁) or to sodium chloride (NaCl). Rearing at 28^oC leads to aberrant responses in adults, but development at low temperature leads to normal-behaving flies.