Staining is first observed in the epidermis of feeding third instar larvae, becomes stronger in wandering third instar larvae and continues into pupal stages. In early pupae, homogeneous staining is seen. At about 70hr after puparium formation, staining becomes localized to the leg joints, proboscis, antennae, and the hinge region of the wing. The pattern persists in adults. At all stages the staining is mainly in the epidermis.
In embryo, expression in PNS not certain.
In wandering third instar larva, no β-gal staining observed.