Acronicta rumicis (caterpillar)

Acronicta rumicis Knot Grass Moth caterpillar

Knot Grass Moth

Thanks to its orange and white spots and long protruding hairs, the caterpillar of the knot grass moth (Acronicta rumicis) is hard to overlook. This is also because, unlike the adult moth, it is diurnal.

Knot Grass Moth caterpillar

The colouration of the caterpillar is variable. The ground colour can be orange, dark brown to black. A nice collection of pictures can be found here.

black orange hairy caterpillar

The caterpillars of the knot grass moth like to eat dock and the closely related rhubarb. However, they can also be found on many other plant species. They even do not seem to disdain poisonous spurge plants.

Acronicta rumicis caterpillar

Although it feeds on many plants that also grow in my garden, I have so far only encountered this caterpillar on a cycle path and a wall.

caterpillar Knoth Grass Moth
The Knoth Grass Moth caterpillar on a cycle path.
hairy caterpillar
The caterpillars can be seen from May to October, when they pupate to overwinter.
the head of the caterpillar
Adult caterpillars are between 35 and 38 millimetres long. They live in forests, on shrub banks, embankments, in gardens and parks.