Assembling Northern Eggars

On Friday 3rd June 2011 I discovered that a female Northern Eggar had emerged from a caterpillar found on Barden Moor last year.
Having read about "assembling" I took the moth up to Baildon Moor in the late afternoon sunshine and placed it carefully on a clump of bilberry.
Within a couple of minutes, a male arrived swiftly followed by another, and then another.
The two surplus males soon did the decent thing and allowed the first arrival to complete his courtship.