Homozygous Df(3R)ΔTk² mutant flies exhibit reduced sensitivity to (S,Z,Z)-CH503 (a more potent stereoisomer of the gustatory sex pheromone CH503): in contrast to wild type they do not exhibit increased courtship defects in the presence of (S,Z,Z)-CH503 compared with controls.

Df(3R)ΔTk² mutant flies are fully viable and fertile and exhibit no obvious anatomical abnormalities of differences from controls in locomotor activity. Homozygotes show a significant decrease in male-male aggressive behavior compared to heterozygous controls. Males copulate with virgin females at efficiencies comparable to those observed for heterozygous control males. Copulation latency and latency are unaffected, as is the frequency of unilateral wing extension "singing" toward mated females. The frequency of unilateral wing extension toward other males is also not consistently different from controls.