Treble-bar

The treble-bar or '''St. John's wort inchworm' (Aplocera plagiata) is a moth of the family Geometridae. the species was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae. It is found throughout the Palearctic region and the Near East.

This species varies considerably in size (wingspan 37–43 mm) and colouration but is generally grey with three characteristic dark fascia across each forewing, giving it its common name. The hindwings are pale grey or buff. Many forma have been described. See Prout (1912–16) Aplocera plagiata is difficult to certainly distinguish from its congener Aplocera efformata'' See Townsend et al.