The Barberry Carpet Moth

Graeme Davis is a guest contributor. 28^th June 2021

The Barberry Carpet is a medium size British moth, now reduced to 12 colonies, though this is a recent increase in numbers, thanks to a project by Back from the Brink. The moth is a red data book species, and on the UK Biodiversity Action Plan for protection.

Back from the Brink is a project made up of several leading charities to save 20 of the most at risk species from extinction. Amongst this group of organisms the Barberry Carpet moth was included.

Fiona Haynes worked on the project under the lead charity (Butterfly Conservation) to help save this fragile species.

The issue: Barberry Carpet moth has declined across the UK as its larval food plant has been removed by farmers, to eradicate a rust disease which effected wheat. The moth feeds on native Barberry (Berberis vulgaris), a bush of woodland and hedgerows. Unfortunately, the bush also acts as a vector for the rust, and because of this barberry was grubbed out from the countryside. The plant is now uncommon, and missing from many of the counties where it previously occurred. As a result, the moth numbers have plummeted, and it is now only found in Wiltshire, Gloucestershire, Dorset and Oxfordshire.

When and how the barberry bushes are cut is also an important issue for the survival of this species – the few hedges that remain must not be trimmed until late autumn.

The Hampshire colony: Hampshire had its own colony of Barberry Carpets moths. Unfortunately, this was lost due to stubble burning.  Since then short lived colonies have existed in Cholderton and Leckford (both near Andover).

I became aware of the plight of the Barberry Carpet moth, and contacted Back from the Brink. With the Hampshire colonies long gone, but Wiltshire is adjacent, I wondered … could Hampshire help? The moth does not disperse well, so the chances of natural reestablishment are very slim. However, as the barberry plant also provides food for the larvae of the scarce tissue moth and barberry sawfly, so it was worth a go. If the food plant is not provided then they will never increase.

Around 250 seeds of the rare native barberry plant were given to me. This was given to volunteers in Andover to grow on, and some were also given to Hillier Garden Centres to grow. A stipulation to the planting of new barberry bushes is that they can not be grown within 10 metres of wheat fields. Although the new strains of wheat are rust resistant, this was deemed sensible as a precaution.

At the moment the barberry plants are still being grown and not yet planted. One problem with  barberry is its a slow growing plant.

Back from the Brink themselves have planted 4000 barberry plants over 4 years. These have been targeted at increasing the plant in known populations and making corridors between colonies, like in Wiltshire and Gloucestershire to help them disperse.

Hopefully with this concerted effort of charities and volunteers the Barberry Carpet moth may have a chance at surviving into the future.

David says:

I have a native barberry in the garden and contacted Graeme as I found the larvae below, thinking it was the barberry moth. It turned out to be the sawfly. My own attempts at growing the seeds and taking my own cuttings failed last year.

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