A "SPARC2-D" module separates 20XUAS regulatory sequences from sequence encoding a Drosophila codon-optimized version of GtACR1 that is tagged with EYFP. The SPARC2-D module comprises: 1. a STOP cassette that is flanked by two full-length (60bp) attP sites, 2. ribozyme sequence (to prevent leaky expression in the absence of phiC31:int) and 3. an attB site. phiC31:int catalyzes irreversible recombination between the attB site and one of the two attP sites; if the attP site upstream of the STOP cassette is utilized, the STOP cassette is excised, permitting expression of EYFP-tagged GtACR1, while if the attP site downstream of the STOP cassette is utilized, the STOP cassette is preserved.