Stem-mine: An inconspicuous external stem mine, frass in widely-spaced grains. Pupation in the mine (Spencer, 1972: 27).

The mine begins as a corridor in a leaf, descends from there as a rind mine; there also the pupation (Bladmineerders van Europa).

Larva: The larva is described by de Meijere (1937: 186, as O. sp.) and Dempewolf (2001). Posterior spiracles each with 4-5 bulbs (Bladmineerders van Europa).

Puparium: Black; posterior spiracles each with 4-5 bulbs (Spencer, 1972: 27).

Comments: Galium mollugo is treated as Galium album (Hedge Bedstraw) by Stace (2010).

Hosts in Britain:

Hosts elsewhere:

Time of year - mines: June-July and August-September (Hering, 1957).

Time of year - adults: August-September.

Distribution in Great Britain and Ireland: Uncommon. Suffolk (Woodditton Wood) and Surrey (Betchworth) (Spencer, 1972: 27).

NBN Grid map:

Distribution elsewhere: Widespread in continental Europe including Germany (Dempewolf, 2001: 77; Bladmineerders van Europa), Corsica, Czech Republic, French mainland, Lithuania, Poland, Slovakia and Spanish mainland (Martinez in Fauna Europaea).

NBN interactive distribution map(s) of known host species in Great Britain and Ireland and elsewhere:

Parasitoids in Britain and elsewhere: Unknown.