ScerGAL4pyx.PS drives expression in 50 scolopidial dendritic cap cell of the Johnston organ forming a ring located at the distal end of the scolopidium array. In a lateral view, this ring of scolopidial dendritic cap cells labeled with ScerGAL4pyx.PS is on the outside of the ring formed by the chordotonal neurons labeled with painGAL4.