Weekly Highlights: W/C 15th May

Despite poor weather conditions Monday to Wednesday this week, suitable conditions prevailed on Thursday and Friday allowing me to get outdoors. On Thursday I visited Trecastle Landfill Tip near Llanharry, while on Friday I visited Cwmaman Land Reclamation Site (reclaimed coal tip) near Aberdare.  Here are just a small selection of the days finds.


Microdon myrmicae/mutabilis – A scarce hoverfly of wet habitats such as valley mire, wet meadows, and wet heathland and moorland. The slug-like larvae are parasites in the nests of ants. 


Xanthogramma citrofasciatum (Barred Ant-hill Hoverfly) – A widespread but localised species strongly associated with grassland and open-structured scrub with ant hills of Lasius flavus. It is believed the that the larvae feed on ant-attended aphids within the nests. 


Bombus monticola (Bilberry bumblebee) – A bee of upland moorland areas of northern and western Britain, it requires a landscape mosaic with Bilberry-rich moorland as just one of the components. This is an iconic species of the south Wales valleys and coal tips. 


Bombus humilis (Brown-banded carder bee) – Once widespread in lowland Britain, this species suffered a substantial decline during the 20th century. South Wales is one of its national strongholds, and these bees are a familiar site on the coal tips of the south Wales valleys. It exploits a wide variety of different habitats. This queen was observed foraging on invasive Cotoneaster


Erynnis tages (Dingy skipper) – An iconic butterfly of colliery spoil tips, so much so that you’ll struggle not to find it! The Dingy Skipper is locally distributed throughout Britain but has experienced substantial declines in some areas. 


Scarce bee at Lady Windsor Colliery, Ynysybwl

Today I visited Lady Windsor Colliery in Ynysybwl in search of a potentially interesting bee spotted by local resident (and friend) Steven Murray. Looking at Steven’s pictures of a nesting female, it appeared to resemble the Cat’s-ear Mining Bee (Andrena humilis) – a scarce species listed as Notable B in Falk (1991) (now known as Near Threatened).

Andrena humilis is widespread but very localised in southern and central Britain north to Cumbria. It is found in a variety of habitats but is mostly found in heathland and coastal districts. Pollen is obtained entirely from yellow hawkish composites such as Cat’s-ear, Mouse-ear Hawkweed and hawk’s-beards. Adults fly from May to July and nesting usually occurs along footpaths. Further information is available on the BWARS website.

Following a grid reference given to me by Steven, I started my search for the nests. Thankfully, the nests were relatively east to find, situated on a footpath beneath a rather distinctive oak tree. I noted what looked like 6 nests, although after waiting for almost an hour, I could see no sign of activity.  I decided to try again later.

On my return an hour or so later, I spotted a female pocking her head out of her nest. After patiently sitting beside the nest entrance, I watched her emerge and head off foraging (see sequence below).

Female Andrena humilis emerging from her nest

Around 5-10 minutes, she returned with pollen-loaded legs. Catching her in a net, I had a closer look and confirmed the bee to be Andrena humilis.


Female in a pot for a closer look

I also observed several males flying around a female foraging on a yellow composite well away from the nesting area (see below), suggesting further nests may be present elsewhere on the site.


Female foraging on yellow composite

I would like to take this opportunity to congratulate Steven Murray on his excellent find. This is another exciting discovery for the coal tips of south Wales, and represents the second coal tip in Rhondda Cynon Taf supporting this scarce species.


Liam Olds

Colliery Spoil Biodiversity Initiative



Rare bee discovered on coal tips in the Rhondda Valleys


A pinned specimen of Andrena falsifica from Whitbarrow, Cumbria © Steven Falk

A rare bee, last recorded in Wales in 1967, has been discovered in the Rhondda valleys. The Thick-margined Mini-mining Bee (Andrena falsifica) is a rare and poorly understood solitary bee species with scattered records as far north as Cumbria. It has only been recorded in Wales on three occasions: at Tregarth, Gwynedd, in 1967 (recorded by J. Morgan) and at St. Donats, Vale of Glamorgan, in 1929 (recorder unknown) and 1932 (recorded by H. M. Hallett). In South Wales, it hasn’t been recorded for around 84 years!

But, what are solitary bees?

In Britain, we have around 270 different species of bee. The social bees (bumblebees and the honeybee) account for around one-tenth of that figure, the remainder of which are solitary. Unlike bumblebees and the honeybee, solitary bees do not live in colonies, produce honey or have a queen. Solitary bees live largely independent lives, building and provisioning their own nests without the help of a worker caste. These charismatic and highly diverse bees are readily overlooked, despite the valuable pollination service they provide. Solitary bees are fantastic pollinators, and it is said that a single red mason bee (Osmia bicornis) is between 120 and 200 times more efficient at pollination than a honeybee.

Solitary bees are highly diverse, and so are their nesting habits. The majority of British species nest in the ground, excavating their own nests. The appropriately named Mining bees (in the genus Andrena) are ground nesting species. After choosing a suitable piece of ground, the female mining bee begins excavating a nest by digging. After creating the nest, she provisions the nest with nectar and pollen, everything her developing larvae needs to grow and develop. Solitary bees do not tend to the young as they grow, as bumblebees and honeybees do.

Andrena falsifica

In Britain there are around 65 species of bee in the genus Andrena, making the mining bees the largest of our bee groups. Among these mining are the mini-miners (subgenus Micrandrena), which are among the smallest of our bees (with many often measuring just 5 to 7 mm in length). The rare mini-mining bee Andrena falsifica was discovered by Liam Olds (founder of the Colliery Spoil Biodiversity Initiative) as part of his ongoing research highlighting the important wildlife value of south Wales’ coal tips. Relatively little is known about this bee, although many records are from heaths and moors. It is thought to forage on a wide variety of flowers including a cinquefoil, dandelion, Daisy, Wild Strawberry, Germander Speedwell and umbellifers. The bee was found at three different Rhondda coal tips – Tylorstown Tip (‘Old Smokey’), Gelli Coal Tips and the reclaimed tips of Clydach Vale Country Park.

Image 2

Gelli Coal Tips – one of the sites supporting this rare bee in the Rhondda © Liam Olds

Commenting on the find, Liam said “The discovery of this rare bee is very exciting and highlights the importance of our coal tips. Over decades, our tips have been colonised by a wide variety of plants and animals, and many now support habitats and species of considerable local and national importance. This discovery is just one of many other rare and scarce invertebrates, lichens, plants and fungi that have been found on coal tips. Coal tips are not only important wildlife habitats, but are part of our industrial heritage and cultural identity and they need conserving. The Colliery Spoil Biodiversity Initiative will continue to raise awareness of the importance of coal tips for wildlife and people in an attempt to aid their conservation”.

Please follow the Colliery Spoil Biodiversity Initiative on Facebook and Twitter, and spread the word about the importance of coal tips (and other brownfield habitats) for wildlife.

If you would like any further information on solitary bees, check out Ryan Clark’s Guide to Solitary Bees in Britain. For further information on Andrena falsifica, visit Steven Falk’s Flickr page and the BWARS website.