What kind of caterpillar is this?

Answer

Dear Marieke

this seems to me to be the caterpillar of the evening primrose pintail butterfly (Proserpinus proserpina). It is a fairly rare species that is on the rise. It is protected under the Habitats Directive. Fully grown caterpillars of this moth are remarkably large in relation to the butterfly and have a dull yellow spot where the characteristic spine of other species is located. The species overwinters as a pupa in the leaf litter.

Adult pintails are impressive, medium to large, often strikingly colored moths. A number of them belong to the largest moth species that occur in Belgium, both because of the wing length and because of the body size. The flight is characterized by great speed and maneuverability. However, the evening primrose pintail is a relatively small and stocky pintail with an irregularly serrated green or brownish green, dark barred forewing and an orange-yellow hindwing with black margins. This species can be found on willowherb, evening primrose, western lavender and loosestrife, in damp forest clearings, forest edges and warm clearings … and apparently in your garden too.

Sincerely

jochem