Flight period: May to August (occasionally April)
Both sexes have a small blue line between the eye spots.
Male: anti-humeral stripes are usually broken, like two exclamation marks. S2 has a “wine-goblet” shaped marked, usually joined to the inter-segmental line by its stalk, though this character is quite variable. S8 is blue but S9 is mainly black.
Female: blue with more or less extensive black markings.