About Perconia strigillaria (Hübner, 1787)
Perconia strigillaria, the grass wave, is a moth in the family Geometridae, first described by Jacob Hübner in 1787. It is distributed across Europe, eastward to the Urals, Asia Minor, and China's Tarbagatai Mountains. The wingspan of this species ranges from 36 to 41 mm. The forewing ground color is white with dark speckling, known as fuscous irroration. The crosslines are wide, and the antennae have a comb-like structure. The full description notes that this moth is white with fuscous irroration, all standard lines are present, and a dark subterminal line is usually present as well. The median line or shade varies in position and thickness. Several distinct aberrations and forms are recorded: ab. herpeticaria Rbr. has thick, closely approximated antemedian and median wing lines, which are sometimes confluent into a single band. grisearia Stgr. is a grayer form where the white ground color is nearly completely suppressed. This form is frequent in Northern Europe, but is not very sharply separated from the standard name-type, and most British examples are intermediate between the two. cretaria Ev. is a clearer white, weakly marked form from southeastern Russia, and may sometimes be completely markingless. Adult moths fly from June to July, depending on location. The larvae feed on Cytisus scoparius, as well as species from the genera Calluna, Erica, and Ulex.
