In a significant milestone for Irish biodiversity, the elm leaf-mining micromoth, Stigmella viscerella, has been documented in Ireland for the first time. This important discovery was made in October near Carrigtwohill, Co. Cork by John Emmet O’Sullivan, Project Manager of Nature Network Ireland’s Valuing Insects initiative.
Six distinctive, coiled mines created by this micromoth caterpillar were identified on the leaves of Wych Elm in a hedgerow outside Carrigtwohill. The find represents a remarkable extension of this species’ previously known range in Europe, as it had only been recorded as far west as Liverpool in England until now.
“Stigmella viscerella larvae mine Elm leaves, meaning they feed in between the top and bottom layers of a leaf,” said John. “In doing this they create distinctive mines that are shaped like intestines which is where they get their species name visceralla from, referring to viscera. Finding Stigmella viscerella in Ireland is something of a milestone for the Valuing Insects initiative in understanding insect diversity in the country. This tiny moth’s presence here shows how our native insect biodiversity continues to surprise and is ever changing. It also highlights the persistence of species of Elm in Ireland, even in the face of significant challenges like Dutch elm disease.”
He further explained, “This disease significantly impacted elm populations, which may have limited the diversity of elm-associated insect species in Ireland until now. The distinctive mines on Wych Elm leaves are a testament to the incredible complexity of our ecosystems and the importance of conserving them for future generations.”
The discovery highlights the importance of biodiversity monitoring and the vital contributions of citizen scientists. John’s findings, soon to be published in the Irish Naturalists’ Journal, build on decades of research into Elm-associated biodiversity across Europe, offering fresh insights into Ireland’s insect fauna.
It also aligns with the broader goals of Nature Network Ireland’s Valuing Insects project, which seek to highlight the ecological importance of insects to the public as well as underscore the importance of protecting hedgerows and semi-natural habitats, which serve as vital refuges for common and rare species.
