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).
Trifolium repens | Ranunculus repens | Melinis repens | Elymus repens | Elymus | Dichondra repens | Habenaria repens | Elymus glaucus | Elymus (genus) | Coprosma repens |
Adults and larvae are vegetarian and polyphagous, on grasses such as couch-grass (Elymus repens), false oat-grass (Arrhenatherum elatius) and reed canary-grass (Phalaris arundinacea).