Food Plant: Cytisus/ Sarothamnus (Broom), Genista tinctoria (Dyer's Greenweed).

Egg: On a stem. The egg is not filled with frass and soon drops off when the larva hatches (which distinguishes it from Trifurcula immundella, where the egg remains, but Richards (2022) found that egg cases remained attached in 50% of the mines examined).

Mine: September-May

Pupa: In a white silken cocoon attached to a stem.

Notes: A gallery in the bark of the food plant generally mining upwards, similar to that of Trifurcula immundella, which usually mines downwards. A mine in a woody stem of Genista tinctoria in autumn. The yellow larva is visible on the left, mining close to the surface of the stem. Adults were reared and dissected from these mines to confirm the identification.

Data: 08.x.2023, Thorney Island, West Sussex, VC13

Image:© Will Langdon