Ectropis is a genus in the geometer moth family (Geometridae). They are mostly paleotropical, but also plentiful in Australia and extend into Asia. Only one species - or cryptic species complex - (the engrailed/small engrailed, E. bistortata/E. crepuscularia) is found in Europe. There are about 100 known species in this genus.[1]
All junior synonyms of Ectropis use G. crepuscularia as type species, and thus, even though this large genus might warrant subgeneric division, no names are presently available. Apart from Tephrosia, established by Jean Baptiste Boisduval in 1840, the synonyms are also junior homonyms and consequently completely invalid.[2]
One of them, Coenobita, was proposed by Johannes von Nepomuk Franz Xaver Gistel in 1848. Gistl was unaware that Jacob Hübner had described the genus Ectropis, but he knew of Boisduval's Tephrosia. However, Gistl misread the name of the spider genus Theraphosa (established by Charles Athanase Walckenaer in 1805) as Tephrosia, and thus came to believe that Tephrosia was in need of a new name. He chose Coenobita, which to his misfortune had been given to a genus of hermit crabs by Pierre André Latreille in 1829 already.[3]
The other preoccupied synonym, Boarmia, had earlier been given to closely related moths. That group is now included in Hypomecis, which thus has become the type genus of the tribe Boarmiini in the geometer moth subfamily Ennominae. Ectropis is also a member of the Boarmiini.[4]
Species of Ectropis include:[5]
Some species formerly included here are now placed elsewhere, e.g. in Calcyopa, Myrioblephara or Parectropis