Butterfly Education & Awareness Day: Mr Ray’s Purple Butterfly

The 7th June 2025 is Butterfly Education and Awareness Day and, to mark this, we thought we would write about “Mr Ray’s Purple Streak Butterfly”. This was the English common name given by James Petiver in 1702 to the butterfly that is commonly known today as the Purple Hairstreak (Favonius quercus).

James Petiver was a friend and sometime assistant of John Ray. Petiver was subsequently described as “the father of British butterflies” as a result of his detailed work on the identification and classification of butterflies. He also gave every species he identified an English common name, which for many species remains the name by which we know them today.

Francis Willughby of Middleton Hall excelled in entomology. At his death he left his work unfinished but he did specifically ask Ray to finish his work on insects. Ray only turned his attention to this subject in his senior years. He undertook further research and investigations in order to complete Francis Willughby’s Historia Insectorum. Insectorum was published after Ray’s death by the Royal Society under Ray’s name alone. As was typical for Ray and Willughby’s work, they did not give anything a name beyond a Latin descriptive name. Thankfully, Petiver clearly connected the butterflies described in Insectorum to the ones in his own work and this is how we know for certain that the Purple Hairstreak was described in Insectorum.

The Purple Hairstreak is a small, elusive but common British butterfly. All stages of the development of this butterfly are exclusively dependant on oak trees and a single oak tree can support an entire colony of Purple Hairstreaks. They are elusive because they very rarely leave the tops of oak trees and are normally only driven lower to seek fluid and nectar during droughts. However, on warm July evenings, if you look towards the top of oak trees, you may be lucky enough to see them fluttering about.

Male Purple Hairstreak Butterfly. Photograph taken by Charles J. Sharp, CC BY-SA 4.0, via Wikimedia Commons.

The Trust was also told a story about an observation of the Purple Hairstreak at Middleton Hall. This story concerns a gentleman who was interested in natural history and John Ray and so set off to visit Middleton Hall. At the time of his visit, the Hall was still a ruin and he did not hold out much hope of seeing anything of interest that would enable him to engage with the Hall’s historical association with John Ray. He stopped his car close to the entrance by the crossroads and began to walk along the entrance drive. Almost as soon as he had left his car, he spotted Mr Ray’s Purple Butterfly fluttering amongst the oak avenues along the entrance drive. He was absolutely ecstatic at this unexpected sight, even more so because it was the first thing he observed, and imparted how worthwhile his visit had been for this connection to John Ray alone.

The Purple Hairstreak is still recorded at Middleton Hall. However, despite the large number of oak trees in the grounds, it has so far been elusive enough to be able to avoid having its photograph taken by the Trust volunteers!

Further Reading: John Ray, Historia Insectorum, 1710, p.130.

James Petiver, Papilionium Britanniae, 1717. https://www.biodiversitylibrary.org/partpdf/297418

Richard I. Vane-Wright, "James Petiver's 1717 Papilionum Britanniae: An Analysis of the First Comprehensive Account of British Butterflies", Notes and Records The Royal Society of London Journal, 74 (2), 2020, pp.275-302. https://royalsocietypublishing.org/rsnr/article/74/2/275/54969/James-Petiver-s-1717-Papilionum-Britanniae-an

Author - Debbie Jordan, Middleton Hall Volunteer.

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