White-letter Hairstreak butterflies are quite rare in Dorset; their caterpillars breed on elm trees, so finding the trees will help us find the butterflies. You can help us map some of the remaining healthy Elm trees in Dorset and by so doing help us locate some of our missing White-letter Hairstreaks (WLH)
Nigel Spring writes about finding Elms:
Most of our Elm trees were killed by Dutch Elm Disease (DED) 50 years ago and the suckers that grow up from the roots are usually killed when they reach around 20 years old. Additionally, many of the elm hedges on agricultural land are repeatedly flailed and are now not suitable for WLH.
However, on our local walks recently in north Dorset, we have found a fair number of healthy good-sized elm trees that could well be supporting hidden colonies of the WLH butterflies. We have marked them on a map and are planning to go back to those trees in June/July to try to find out if there are any WLH there.
You can help us in our search to find more of the elms detailed in our Search for the Elms article (2)
HOW TO TELL US WHAT YOU FIND
Please tell us:
- Whether you found elm trees singly, or in groups or forming tall hedges which do not appear to be suffering from DED and are not flailed.
- The name of the place where you found them (the nearest village, farm or town)
- A 6-figure Ordnance Survey map reference if possible, or at least the 4-figure reference for the km square. We have a page on how to read grid references to help you with this.
- A photo of the tree/group and a close-up photo of the leaf (if possible)
Please email this information to: [email protected]
If you would like a copy of the present distribution map for WLH in Dorset please email Nigel Spring requesting one.
More information about this species of butterfly can be found on our WLH species page.
We will be following this up at the end of June with a search for White-letter Hairstreaks and the results of this survey will be published in due course on the website of Butterfly Conservation Dorset Branch http://www.dorsetbutterflies.com