The brown hairstreak lives in the canopies of ash trees
The public are being asked to report sightings of the rare brown hairstreak butterfly, living in an area of ancient woodland in Worcestershire.
Grafton Wood is a remainder of the old Forest of Feckenham.
It's believed to be the home of the only colony of this rare butterfly in the Midlands.
The colony may be growing, and people are being asked report sightings in Trench Wood, Feckenham Wylde Moor and Humpy Meadow.
Worcestershire Wildlife Trust
jointly own Grafton Wood, which is near near Grafton Flyford.
Mike Williams, West Midlands Butterfly Conservation Species Champion, said: "We'd like to know of any ash trees that are being used by the adults.
"It can be difficult to see the butterflies, as they tend to stick to the canopies of trees - but they do occasionally descend, and it may be that some people have noticed butterflies flying around an ash tree from their upstairs windows.
"The butterflies are best spotted early in the morning, before 0900 BST, on warm sunny days."
The two charities organise an annual Brown Hairstreak Day at the end of August, to look for the female butterflies who descend to lay their eggs.
In 2010 this takes place on Sunday, 29 August - anyone interested in taking part should contact John Tilt on 01386 792458.
Anyone who has spotted brown hairstreak butterflies, or thinks they know of suitable ash trees, should contact Mike Williams on 07802 274552.