Food Plant: a wide variety of grasses

Egg: near the tip of the leaf

Mine: autumn - May

Notes: It makes a small narrow mine in the autumn and overwinters. In the spring it changes leaves and mines tip downwards. The mine fills the leaf width. The frass is packed in the top of the mine. A young larva mining Festuca sp. in mid-winter. Very young larvae are initially yellowish and make a mine that is not the full depth of the leaf, with scattered black frass, as shown here, one of a number of mines from which adults were reared. On Festuca spp. larvae will mine several leaves, turning greyer and producing full-depth mines as they grow. Full depth mines completely remove all the tissue from the leaf, often causing it to become weak and bend (as can be seen in the leaf tip here), and the mine to bulge around the larva as it feeds.

Data: 29.xii.2022, Watchet, Somerset, VC5

Image:© Will Langdon