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Thanks to support from SEWBREC (South-East Wales Biodiversity Records Centre) outreach fund, we hosted a workshop on butterflies at Global Gardens Project this month.

We were joined by the knowledgeable and passionate butterfly expert Ben Williams – author of “Butterflies of Rhondda Cynon Taff.”

Ben started his working life as a firefighter. However, since his childhood, he has been a butterfly enthusiast. In later life, he worked as Rivers Officer for Keep Wales Tidy and, following his passion of this fascinating family of metamorphic creatures, has explored butterfly habitats across the world. Most recently, he has been involved in the Marsh Fritillary reintroduction project at Llantrisant Common. He came to share his enthusiasm for butterflies at Global Gardens.

Butterflies in Wales

There are around 560 butterfly species in Europe and 59 in Britain with around 35 in Wales. We have a slightly more limited range of butterfly species in Wales due to the lack of chalklands.

In the workshop, Ben introduced us to a number of the key butterfly families – including the Whites, the Blues, the Vanessids and the Hairstreaks.

Ben distinguished between generalist butterfly species – which will eat many kinds of plants and specialists butterfly species – which tend to eat only specific plants.

We learnt that some butterflies can be very specific indeed. The Brown Hairstreak, for example, will only lay eggs on 1 metre tall, south-facing Blackthorn that is below 500 metre sea level! Whilst the High Brown Fritillary feeds only on violets found growing under bracken on south-facing slopes.

Welsh Butterflies at Threat

Butterfly populations are currently at threat in Wales – both due to changing climates as well as intensification of agriculture.

Changing climates are leading to new potential pests and diseases that can impact butterfly populations – including for example a parasitic wasp that is decimating the Small Tortoiseshell in the UK.

Intensification of food growing and the use of agrochemicals in recent history has further been resulting in loss of habitat and forage for butterfly species.

Ben reflected that this year particularly has been a challenge for butterflies – with the very dry start to the summer coupled with the cold and damp July.

Landscapes of Hope

However, Ben’s explorations in South Wales have revealed microcosms of butterfly diversity – including in the post-industrial ex-mining landscapes in the valleys which provide a unique and distinct habitat for a range of butterfly specie – as well as in gardens across Wales.

Ben spoke about the mystery of butterfly migrations. Monarch butterflies for example make their annual migration from Northern parts of America to Mexico and California, travelling up to 80 miles per day! Monarchs have also been reported to have been sited on Lavernock Point on the coast west of Penarth – making an epic trans-atlantic flight.

Ben also shared a magical film he made which shows the emergence of a butterfly from its pupae. We recommend you watch it! …Did you know that when butterflies emerge from their pupae they take a little while for their wings to get to the size where they can fly?

Butterfly Families

In the following section, we share some of the most common butterflies that can be spotted in Wales, including in your garden.

The Whites

In terms of the whites, Ben explained an important disctinction between the Large and Small White butterflies – which are probably familiar to most brassica growing gardeners.

The Large White butterfly tends to lay a large number of eggs on brassica plants. When the eggs hatch into a stripey caterpillar, they tend to voraciously munch their way through most brassica plants.

In contrast, the Small White butterfly lays single eggs, which hatch into bright green caterpillars. These tend to be less of a menace to brassicas since they are smaller in numbers – although they can still munch their way through many a kale and cabbage plant!

The Brimstone is another species of the ‘Whites’. Males are bright yellow whilst females are green-white. An important food source for Brimstones is Sea Buckthorn.

The Hairstreaks

We also learned about the elusive Hairstreak butterflies which tend to remain high up in the canopy of oaks, ashes and poplars – often only flying down to lay eggs. Many of the Hairstreak species feed on honeydew rather than flower nectar.

Purple Hairstreaks, for example, tend to lay eggs in Oak trees and you may only see them at ground level in the night.

The Blues

You may have seen very delicate, small blue butterflies flying across grasslands. These are probably the Common Blue – which tend to favour Vetch, Bird’s foot trefoil and other leguminous plants. Females in the first brood of the year tend to be brown toned whilst the second brood tends to be a more vivid blue.

The Vanessids

The Vanessids are the glamourous species of the butterflies. They include Red Admirals, Small Tortoiseshell and the magnificent Peacocks as well as the distinctive Comma. The Painted Lady is a less common Vanessid but quite remarkable in that it makes its journey to Wales all the way from the Atlas Mountains in Morocco.

Many of the Vanessids favour nettles for laying eggs – including the Comma, Painted Lady, Peacock and Small Tortoiseshell. As well as nettles, Painted Ladies also favour thistles, mallow and viper’s bugloss.

The Fritillaries

The Fritillaries include a range of quite rare butterfly species .

The High Brown Fritillary which is found in only one place in Wales whilst the Pearl Bordered Fritillary is also very rare and only found in one place in Ceredigion.

The Marsh Fritillary which is making a comeback but favours only ‘rhos’ rough pasture

The Silver Washed Fritillary however can be spotted in South Wales at Fforest Fach near Castell Coch on the woodland rides.

Key messages for Welsh gardeners and butterfly fledgling enthusiasts:

Leave weeds for caterpillars!

Dandelions for example offer important early forage for butterflies as well as some of the first seeds for birds.

Leave wild patches in your garden

Many butterfly species lay their eggs on nettles and they are an important food source for caterpillars.

Get out in nature and observe

Walking through varied landscapes – such as the coast, woodland glades and rides and meadows can provide great opportunities for butterfly spotting. You can also take part in the annual Big Butterfly Count July to August!

Don’t give up!

We can all make a difference by using agroecological approaches, avoiding the use of agrochemicals and getting closer to nature.


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