Species Focus - Puss Moth (Cerura vinula) and Sycamore (Acronicta aceris) Caterpillars

Most moth records we receive at Cofnod are of adults, typically caught alive in specialised light traps. This recording method is highly effective and can generate lots of records from a site. Unfortunately, investing in a good moth trap is often a barrier to recording moths.

However, although many adult moths are brightly coloured and easily identified, we should not forget about their immature stages. Indeed, many moth caterpillars are amazingly well marked, often with extravagant body shapes adding to their appeal. You don’t even need specialist kit to find them either. By homing in on a preferred foodplant at the right time of year you might be lucky to spot them within the foliage, or you could beat branches with a stick over an upturned umbrella to dislodge them.

Two particularly wacky and distinctive caterpillars you might like to go hunting for this month are Puss Moth and Sycamore.

Puss Moth (Cerura vinula)

This charismatic caterpillar can by found between June and September on Poplars and Willows in sunny situations. It has two tails and larger caterpillars have a dark saddle, white spiracle portholes along the side, and distinctive eye spots which, in combination, help to distinguish it from related species.

Sycamore (Acronicta aceris)

As with the Puss Moth, this caterpillar can be found between June and September, but its foodplants include Horse-chestnut and various Maples – particularly Sycamore trees. Its bright yellow and red colour and long setae (hair) make this Muppet of a caterpillar easily identified in the field.

If you want to learn more about caterpillars it is well worth getting the “Field Guide to the Caterpillars of Great Britain and Ireland”, published by Bloomsbury Wildlife Guides (ISBN978-1-4729-3356-0).

Please submit your records, ideally with photos, to the Cofnod ORS or the LERC Wales App.