Orthonama Obstipata

The Gem (Orthonama obstipata) is a moth of the family Geometridae. It is a common species of Continental Europe and adjacent lands, though in the northeast, its range does not significantly extend beyond the Baltic region and it is absent from northern Russia. This well-flying species is somewhat prone to vagrancy and able to cross considerable distances of open sea; it can thus be regularly found on the British Isles (though mainly in the south) and even on Iceland.

Under its junior synonyms Nycterosea brunneipennis and Geometra fluviata, the Willow Beauty is the type species of genera Nycterosea and Percnoptilota, respectively. The latter is treated as junior synonym of the former, but Nycterosea, though usually included in Orthonama these days, may warrant recognition as an independent genus after all.