Poplar Hawk-moth caterpillars will happily munch their way through willow (Salix sp.).
Photo: Ray Surridge

Scientific name: Laothoe populi

Cornish name: The general word for moth is ‘gouwan’

Conservation status: No designations

The adult Poplar Hawk-moth, our most common native Hawk-moth, is very distinctive, with its upward-curving abdomen and characteristic resting position of holding its hind wings so that they protrude in front of its forewings (see the photograph at the end of this article). In this attitude it resembles a dead leaf, providing excellent camouflage. 

This large grey-brown night-flying moth (sometimes with a more pinkish hue to its wings) can usually be seen flying from May to early August in parks, grasslands, woods and heaths where its larval foodplant grows. Poplar Hawk-moths are strongly attracted to light, so are a common find at moth trapping events. Increasingly, the species is producing a second generation in southern counties, and the range of this occurrence is moving further north. 

The caterpillars can be seen from June to September, feeding, as you would expect, on Poplars, although they are also fairly frequent on Salix species. They pupate through the winter beneath the ground, close to the foodplant, before emergence as adults the following year. It is easy to confuse Poplar Hawk-moth caterpillars with those of the Eyed Hawk-moth: they can be told apart by the spike at the latter’s rear, which is blue-ish compared to the green colouring of the former. Caterpillars of both species have the ability to adopt the predominant colour of their foodplant by ingesting pigmentation. On white-ish Poplar leaves they will therefore be paler than on green Salix species.

Did you know…?

…Adult Poplar Hawk-moths do not feed: although they have a proboscis, it is non-functional.

…When disturbed or alarmed, the moth will flash the rufous-coloured patches on its hindwings

More information and references:

Chinery, M., 2005. Collins Complete Guide to British Insects. HarperCollins, London

Waring, P., Townsend, M. and Lewington, R., 2009. Field Guide to the Moths of Great Britain and Ireland (second edition). British Wildlife Publishing, Gillingham, Dorset.

Published: August 2013
Author: Amanda Scott
Photos: Caterpillar: Ray Surridge; Adult moth: Penny Mayes [CC-BY-SA-2.0], via Wikimedia Commons