There are about 2500 moth species in Britain which vary from a few millimetres in length to over 50 mm in length.  The largest of the resident moth species is the Privet Hawk moth which is about 55 mm in length and has a wingspan of about 120 mm.  This is about the same size at the Swallowtail butterfly which is Britain largest resident butterfly. 

Privet Hawk moths are a reasonably common species in the right habitat.  They are on the wing from mid May until mid August, and have a life span of about 6 weeks as an adult moth.  As their name suggests their food plant is Privet, but as well as Wild Privet, they also like Garden Privet, Ash, Lilac, and other soft wood species.  They are a night flying moth which generally only fly and are active after dusk,.  During the day they can often be found resting on privet, other small bushes, fence posts, etc.  They are more common along the southern counties such as Kent, Hampshire, Wiltshire, Dorset, etc. but can also be found as west as Gloucestershire, and as far north as Nottinghamshire and the West Midlands.

The images below are all of them on wild Privet at a site on Wiltshire and Hampshire border which is well known for these moths.  We were at the site hoping to find some rare orchids and butterflies and were very pleased to find three of these moths during our visit.