Back in September, Doug Fairweather photographed this moth larvae at Tophill Low NR, East Yorkshire.
Caterpillars aren’t the most straightforward of things to identify, and a bit of botany knowledge helps. Foodplants give a good indication.
This caterpillar is pictured on Yarrow Achillea millefolium shortly after the annual cut means the plentiful supply of grasses and Ragwort Jacobaea vulgaris disappears from the site. However, Yarrow is not a known foodplant of the species mentioned in literature.
Considered by Doug to be a dead-ringer for Golden-rod Pug Eupithecia virgaureata the photos were sent off for an expert opinion, and fortunately his identification was accepted as correct given the circumstances – it is likely the caterpillar is a refugee, needing to feed on something after its foodplant was removed.
Despite being common across the county, the species had not previously been recorded in the 10k square Tophill occupies!