Dialectica scalariella
Echium Stilt

Wingspan c. 10mm.

Until recently this species was known in Britain only as a rare adventive, first found in Kent in 2004, with a further record from Scilly in 2019. Breeding was confirmed at Dungeness, Kent, in September 2022, when leaf-mines were found on viper's-bugloss and adults reared. It has since been spreading along the south coast of England, with mines located in Hampshire and widely on the Isle of Wight by late 2024 and for the first time in 2025 on Guernsey.

Elsewhere the moth occurs across southern Europe, North Africa and the Middle East, and it has been introduced into Australia as a biological control agent of Paterson's curse (Echium plantagineum), later spreading to New Zealand.

On the continent there are several overlapping generations each year; British adults and occupied mines have so far been found mostly in the autumn, with tenanted mines persisting into the winter months.

In Britain the larva mines the leaves of viper's-bugloss (Echium vulgare); in its wider range a variety of other Boraginaceae are used, including borage (Borago) and common comfrey (Symphytum officinale). The mine begins as a narrow, winding gallery in the leaf epidermis, later widening into a brownish blotch which may hold more than one larva, and pupation takes place within the mine.