If “drab” can be defined as “not interesting, plain, or dull”, then it seems the wrong adjective to describe this moth, Ophiusa tirhaca, which I find simply stunning in appearance.
But “drab” can also mean “a dull greyish to yellowish or light olive brown”, which I suppose is a more fitting description for the adult females of this species, pictured below.
Green Drabs belong to the Erebidae family of moths and are native to Europe, Africa, Australia, and parts of Asia. The adult female moths have brownish-colored forewings, with a darker, irregular-shaped, broad band along the bottom edge. There is a dark spot near the middle of the wing and a black mark about halfway along the front edge. Males have a similar pattern but the forewings are more greenish, or yellow in several of my observations.
The hindwings of both sexes are yellow with a broad, dark band near the bottom edge.
Host plants include pistachio, pomegranate, sumac, and eucalyptus trees. Eggs are laid on trunks or older stems and the young larvae emerge and search for young leaves to feed on. Older caterpillars can be quite cryptic and difficult to see, resembling the branches they are attached to in shape and color.
Although the larvae might be a pest on some fruit trees, the adult moths are always a joy to spot!