The larvae can be found from November to April and mainly feed on grass species such as Nardus stricta, Festuca and Anthoxanthum aristatum, but also other low growing plants such as Hypochaeris radicata.
The most common plant species that have been found and identified in pastures where affected horses were located include: flatweed (Hypochaeris radicata), sheep's sorrel (Rumex acetosella) and couch grass (Elymus repens).