Aplocera praeformata, known as the purple treble-bar, is a species of moth in the family Geometridae.
Subspecies include: [1] [2]
This species is present from the Iberian Peninsula and France, through Western Europe, over Central Europe, to Russia. Its northernmost range is southern Finland and the Baltic States. [3] [4] The subspecies Aplocera praeformata urbahni is found in Greece. In the Alps it is found to heights of up to 2,000 meters.
Aplocera praeformata has a wingspan of 34–44 mm. The forewings have a gray to blue-gray basic color. They show various bands of dark transverse lines. A red-brown stain extends towards the wing tip. The hind wings are monochrome gray-white without any drawing.
This species is rather similar to Aplocera plagiata.
Adults are on the wing from June to August. [4] This species has one generation a year univoltine. The caterpillars are gray-brown, with a white side line and a dark lower edge. [5] The larvae feed on Hypericum species (St. John's worts), such as Hypericum maculatum and Hypericum perforatum.[6]