About Pennithera firmata (Hübner)
Scientific name: Pennithera firmata (Hübner). The forewings measure 13–16 mm in length, and have a reddish grey ground colour. A darker midfield band is present, with an indented inner edge. The basal field is usually the same colour as this darker band. The hindwing is whitish brown. This species is sometimes unnecessarily confused with the brightest reddish forms of obeliscata. It can be distinguished from those forms by multiple traits: males have pectinate antennae, with 2 pairs of rather short, slender pectinations on each segment; the hindwing is paler with more of a yellowish tinge; the abdomen is pale with a red-brown dorsal line; there is a dark subbasal mark along the hindmargin; the antemedian line is more deeply angulated; the subterminal line is more bluish white or violet-white, and is usually accompanied by some slight violet-grey shading; and a black apical dash is absent. The typical form of Pennithera firmata, which varies very little, inhabits Northern Central Europe, Switzerland, and Austria-Hungary. The subspecies or form ulicata Rbr., found in southern France, Castile, and Lower Austria, has a ground colour that is predominantly pale violet-grey or blue-grey, and a darkened median band. The larva of Pennithera firmata is naked, long and thin, and green with narrow, light longitudinal stripes.
