Food Plant: Eriophorum angustifolium (Cotton-grass)

Mine: September-May

Notes: Mines the stem and lower leaf in the autumn, then overwinters in the mine. In Spring the leaf is mined, initially in the reddish basal part then into the green part of the leaf. The mine is from 20-65mm long. The mine is hidden and frass filled. It then pupates in a cocoon in detritus or in the leaf. The habitat is damp moors, fens and salt marshes. Carefully cutting open a Cotton Grass leaf reveals the larva in the mine. These larvae had pale brown heads and whitish bodies with a faint yellow tinge and a pitted texture. None of these larvae had black spots on T1, but a larva from Lancashire (identified ed via DNA barcoding) did. This feature is given for Monochroa arundinetella in the Moths and Butterflies of Great Britain and Ireland and may be instar-related. Adults reared and larvae DNA barcoded to confirm ID.

Data: 07.i.2022, Westhay Moor, Somerset, VC6

Image:© Will Langdon