Transgenic non-Drosophilid insects have been made using insect transposable elements that have a broad host range such as the piggyBac element. However, the success rate is often low. Previous piggyBac helper plasmids have used either the piggyBac or the hsp70 promoter from Drosophila melanogaster to control expression of the transposase gene. Here we show that plasmids with the piggyBac transposase gene regulated by constitutive promoters can be effective 'helpers' for mediating transposition in D. melanogaster. We also present preliminary evidence on the use of an RNA helper that encodes the transposase. Our results suggest that for germ-line transformation of non-Drosophilid insects it may be advantageous to isolate a constitutive promoter from the species of interest to control transposase expression.