Rare micromoth species discovered in East Cork — a first for Ireland
Ireland First Viscerella, Elm Leaf Documented Has The Micromoth, Stigmella For In Time Been Mining
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, County Cork by John Emmet O’Sullivan, project manager of Cork Nature Network’s Valuing Insects initiative.
The moth is also known as the 'Plain Elm Dot'.
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.
It's not that East Cork is an area unique in having this species however, notes Mr O'Sullivan — it's more that people haven't been looking out for them. Mr O'Sullivan found this particular larvae on leaves at the side of a busy road near a newish housing estate outside Carrigtwohill.
“Stigmella viscerella larvae mine elm leaves, meaning they feed in between the top and bottom layers of a leaf. In doing this they create distinctive mines that are shaped like intestines which is where they get their species name viscerella from, referring to viscera,” explained Mr O'Sullivan.
“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 us 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 also noted: “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 Stigmella viscerella micromoth has a wingspan of only 5–6 mm (0.23").
Mr O'Sullivan says there are many more species likely to be recorded here in coming months and years — indeed he has several leaves and branches with pupae on or in them in storage at his home waiting to hatch out and he will work to identify them then. And he has also found a moth which is 'new to Ireland' on an olive plant at a supermarket chain in a city shopping centre.
This latest discovery highlights the importance of biodiversity monitoring and the vital contributions of citizen scientists. John’s findings, soon to be published in the , 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 Cork Nature Network’s Valuing Insects project, which seeks 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.
- Cork Nature Network is a charitable organisation that seeks to protect Ireland’s wildlife through education, research, and conservation.