White-letter Hairstreak Butterfly

What is it?

Project to Minimise Species Vulnerability: White-letter Hairstreak is a landscape-scale species recovery initiative focused on increasing habitat availability and ecological resilience for the threatened White-letter Hairstreak (WLH) butterfly across Cheshire and Warrington.

The White-letter Hairstreak is closely associated with elm trees, particularly Wych Elm (Ulmus glabra), which historically grew widely across Cheshire. However, Dutch Elm Disease (DED) has devastated elm populations across the landscape, leaving remaining trees fragmented and isolated. Existing WLH colonies are now vulnerable due to the loss of connected breeding habitat.

The project builds upon an existing Butterfly Conservation programme working with landowners and local partners to restore elm habitat through strategic landscape-scale planting. The initiative combines the planting of Wych Elm with smaller numbers of disease-resistant elm varieties, including Ulmus ‘Sapporo Autumn Gold’, which has proven suitable for WLH breeding and more resilient to DED.

The programme also supports community nurseries, volunteer-led propagation, species monitoring and long-term ecological mapping to reconnect fragmented colonies and reduce species vulnerability.

Why is this needed? / Why are we doing this?

The White-letter Hairstreak butterfly has become increasingly vulnerable due to the widespread decline of elm trees caused by Dutch Elm Disease.

While isolated Wych Elm trees still survive across Cheshire, habitat fragmentation means remaining butterfly populations are often disconnected and vulnerable to local extinction. Existing surveys within the Butterfly Conservation branch area have also failed to identify surviving Field Elm populations, highlighting the scale of historical loss.
Without strategic intervention, suitable habitat will continue to decline, reducing the species’ ability to disperse and establish resilient populations.

This project has been developed to restore connected elm networks across Cheshire by combining habitat creation, volunteer engagement, community propagation and long-term monitoring. The programme builds upon approaches already proven successful both nationally and within Cheshire itself, where WLH butterflies have successfully colonised newly created habitat.

What is it going to deliver?

The programme will deliver:

 Strategic Elm Habitat Creation

• Planting of Wych Elm and disease-resistant elm species across the LNRS area
• Integration of elm planting into woodland creation and urban tree replacement schemes
• Strategic landscape-scale habitat connectivity focused on areas within 5km of known or suspected WLH colonies
• Recommended planting ratio of approximately 15 Wych Elm to 1 disease-resistant elm

Community Nurseries & Local Provenance Tree Growing

• Seed collection from locally sourced elm trees
• Propagation through community nurseries and volunteer networks
• Development of locally resilient elm stock
• Support for Cheshire Wildlife Trust tree growing programmes

Species Monitoring & Ecological Mapping

• Mapping of existing elm locations and new planting sites
• Centralised ecological data collection and monitoring
• Mapping of WLH sightings and colony locations
• Integration with iRecord and Butterfly Conservation MapMate datasets
• Monitoring for Dutch Elm Disease and replanting where required

Volunteer & Community Engagement

• Volunteer training in elm identification and WLH monitoring
• GPS recording and citizen science participation
• Expansion of local planting partnerships and community involvement
• Long-term stewardship and monitoring support

The project aims to create connected and resilient elm habitats capable of supporting sustainable White-letter Hairstreak populations across Cheshire and Warrington.