Rare find on North Coast

Image shows the bulbous outgrowths on a meadowsweet plant

A sighting of the rare rough meadowsweet gall on the North Coast in September 2015 was later confirmed as a first for Ireland and the UK.

There are thousands of species of wildlife, plantlife and fungi living on the North Coast. Burrowed inside leaves, hidden under rocks, lurking amid stalks of grass; quietly they grow and spore, and perhaps only attracting attention when flowering colourfully in spring.

In summer 2015, the National Trust gathered over one thousand species records during a ‘BioBlitz’ at White Park Bay, and another thousand records in regular surveys and everyday observations.

During one random survey, carried out at White Park Bay in September, National Trust Area Ranger and conservation expert, Dr. Cliff Henry, made an accidental discovery that turned out to be more exciting than first suspected.

While photographing interesting lifeforms on the leaves of a primrose, Dr. Henry’s attention was drawn to the bulbous formations on a neighbouring meadowsweet plant. The unslightly bumps in the plant tissue, where the leaf connects to the stem, would later be identified as rough meadowsweet gall – home to a colony of gall fly larvae. Blemishes or outgrowths on the plant due to the burrowing larvae is called ‘gall’. The larvae develop from eggs laid on the plant by the tiny female fly which then burrow within the plant tissue. Once there, they benefit from nutrients derived from the plant, and are also protected from predators.

‘It was only after trying to identify the gall on meadowsweet that I realised how rare it actually was,’ explained Dr. Henry, whose previous recordings at the causeway include the first Northern Ireland record of a micro moth and several other types of plant gall. ‘I checked with the Centre for Environmental Date Recording in Belfast (CEDaR) and they suggested I contact an expert in Dublin as it definitely hadn’t been recorded in Northern Ireland before.’  

First for Ireland & UK

After a series of investigations, Dr. Henry’s photograph of the rare gall was verified by the British Plant Gall Society in England.

‘Not only was it a first for Northern Ireland and Ireland, but also for the entire British Isles,’ said Dr. Henry. ‘We also learned that it is very rare in Europe with only one record in Denmark in 2015’.

While everyone else may have lamented the wet summer, and were perturbed by the unseasonable warmth of autumn, the conditions were ripe for the gall fly.

‘The larvae crawl out of the gall in the autumn and are thought to need waterlogged conditions to make their cocoon before emerging the following year,’ said Dr. Cliff.

‘The discoveries in 2015, especially the rough meadowsweet gall fly, makes me think that there are more and possibly rarer still species lying in wait out there still to be discovered.’