Lesion in the 5' end of the Dmau\mariner insertion, where it abuts Dmau\wpch sequences, extending into Dmau\w sequence: 5bp deletion. P{M{peach}wpch-Δ18R} and P{M{peach}wpch-Δ79R} have identical lesions.
Eye colour: mosaic peach/red (<10 spots per eye) in the presence of Dmau\mariner transposase (in an otherwise w- background).