- It has three parts : a ventral or frontal extension, an intermediary segment called the isthmus or insular segment and a temporal or dorsal segment.
- The upper side of the loop is silvery-metallic and there is a silvery-metallic dot on the upper extremity of the dorsal segment.
- Also, the apical dorsal segment may be blue for " Ef . mexicana ", particularly for females . " Ef . surinamensis " females are never blue.
- There is an irregular line from one-fifth of the costa to the middle of the dorsum reduced to a short costal and larger dorsal segment, with a short dash in the middle between them.
- It has eleven posteriorly spinose dorsal segments with a median pair of tubercles on the upper border of the stigmal field . " Lucilia " larvae have posterior spiracles and tend to be larger larvae ranging from 9 18 mm in length.
- Adults are similar to " Choreutis cyanotoxa ", but differs in the absence of the detached dorsal segment of the second blue line of the forewings, which ends at two-thirds from the costa and is connected with the dorsum by a zigzag black line not found in " cyanotoxa ".
- Larva reddish brown, with dark bands on dorsal segments; dorsal line slightly paler : subdorsal pale yellow, narrow; spiracular line brownish, yellow in front . The larvae feed on the leaves of various plants, including " Luzula ", " Gymnadenia conopsea ", " Lotus corniculatus ", " Veronica chamaedrys ", " Rhinenthus alectorolophus " and " Orchidaceae " species.