Heather beetle damage on Dartmoor 2019

I have been very surprised how much Heather Beetle damage there is on Dartmoor this year. The Heather Beetle larvae hatch in June and then feed on the young leaves and shoots. As a result the affected parts of the heather plant turn orange brown.

Heather Beetle damage. It is very characteristic and eye catching.

Last week I walked from Rowtor on Okehampton Common up the military road to Observation Post 15 and then down to Ockerton Court. All the way along the track there are signs of extensive damage to the heather plants – I would estimate that over 90% of plants are affected.

Work carried out in the north of England and in Scotland suggest that the larvae are active until the end of August when they drop down into the litter and pupate into adult beetles. Despite three separate searches on Okehampton Common, the Forest of Dartmoor and Headland Warren Common I only managed to find three larvae and one adult beetle.

Here is a Heather Beetle larvae on Okehampton Common eating the few remaining green leaves of the plant.

I suspect that the absence of larvae and adults during my searches in the first week of August means that the larvae have already dropped into the litter and are beginning to pupate – as a result larvae and adults are not visible. However the very extensive areas of damaged heather indicates that they have been very active in June and July.

It is possible for the heather to recover from this attack and I will be monitoring it to see if it does. However parts or all of the heather plant can be killed. When this happens the shoots turn from orange brown to grey.

This is mature heather at Ockerton Court which has been killed by Heather Beetle

In this image the areas of dead heather (darker brown bits) are being over run by Purple Moor Grass (Molinia caerulea) – the bright green shoots of this year’s growth and the light brown leaves from last year. Molinia is unable to replace heather whilst the heather is alive but can and does do so when it is dead.

Heather Beetle is a seriously under-recorded species on Dartmoor – the National Biodiversity Network database has just one record and the is from Fingle Woods and not from the high moor!

There is clearly a need to gather more records ….

There is anecdotal evidence nationally that Heather Beetle attacks are getting worse and it has been suggested (based on research from the Netherlands) that the severity and frequency of Heather Beetle outbreaks is linked to the levels of atmospheric pollution – particularly nitrogen levels.

Dartmoor receives high levels of nitrogen deposition as a result of its high rainfall – Natural England have reported that Dartmoor receives 24kg / ha / annum of nitrogen (as NOx) which is damaging the blanket bog and mires. This high level of nitrogen deposition may also be responsible for the high levels of Heather Beetle damage.

Heather Beetles are a natural part of the moorland wildlife community and historically damage to heather was limited except in the ‘outbreak’ years. Last year when I was walking the Commons in July I also noticed extensive areas of affected heather – at this point in time heavy attacks appear to be frequent – maybe even annual.

There are implications for wildlife, conservation and hill-farming as a result of these serious Heather Beetle attacks.

  1. The heather plants themselves are either killed or remain stunted
  2. The species of wildlife which feed on heather shoots are also impacted – this includes moth species such as the Emperor Moth and the Fox Moth, whose hairy caterpillars are important prey items for one of Dartmoor’s iconic and successful birds – the cuckoo.
  3. Heather has long been a conservation indicator for the condition of Dartmoor’s Commons and historically grazing levels were reduced significantly to reduce overgrazing pressures to conserve heather.
  4. Heather is also a winter food for sheep on the Commons, if the amount of heather generally is significantly reduced as a result of Heather Beetle attacks it put pressure of the remaining plants that have survived.

Ironically it is thought that the severity and frequency of Heather Beetle attacks has increased because the nitrogen has made the young shoots and leaves more nutritious, it is also reported that sheep preferentially graze the new shoots too for the same reason.

There is a dearth of information on Heather Beetle issues on Dartmoor but from my own observations this year and last it is a potentially serious and widespread problem. However it would also appear that the problem is not universal across the moor. I searched for it in the heather stands around the Warren House Inn  and found Heather Beetle attacks to be minor – perhaps this level of damage is the natural level – whereas the levels seen on Okehampton Common, the north part of the Forest and on Headland Warren Common are the outbreak levels.

It seems to me that there is a clear need to better understand the Heather Beetle situation on Dartmoor, this would be in the interests of Natural England, the Dartmoor National Park Authority and the Dartmoor Commoners Council. The time to survey for the impacts of Heather Beetle is July and August. Maybe a bit of ‘Citizen Science’ could come to the rescue?

I would also be interested to hear from people who have found the characteristic orange brown stands of heather this year on Dartmoor.

I’ve written before about Heather Beetles and this link takes you to my blog which contains further information and some references you can download.

The web of life – badgers, bees and bee-flies

So here is a badger foraging in my garden

It digs holes and scrapes in its search for food

And then …. a Tawny Mining Bee (Andrena fulva) excavates her nest in one of the badger scrapes – the entrance looks like a little volcano.

And this is the female Tawny Mining Bee who excavated this nest

And here she is emerging from her nest

Lurking nearby is the Dark Bordered Bee-fly (Bombylious major) which is a parasitoid i.e. it lays it egg in the burrow of the Tawny Mining Bee (and other species) – its larvae then eat the larvae of the bee

Also lurking in the nearby flower bed is Gooden’s Nomad Bee (Nomada goodeniana) – another parasitoid species, but this a bee not a fly and fortunately for the Tawny Mining Bee it lays its eggs in the nests of other Mining Bee species

And all of this happening in my back garden in Exeter over the past couple of weeks …..

My 25 favourite Dartmoor photographs of 2018

As the year comes to an end I thought I would look back at my favourite photographs that I have taken in 2018 on Dartmoor – I think they capture the spirit of the place along with the people who work there and those who enjoy it.

The day the Commons turned green after some rain and the grass started growing – the sheep and cattle go to the Common

Beating the Bounds at Gidleigh Common – Penny Warren and Crispin Alford clean the boundary stone – even the horse is paying attention

A marsh fritillary at Challacombe – a special butterfly at a very special place

Russell Ashford ‘gathering’ his sheep from Buckfastleigh West Common

This quote from James Rebanks – the Lake District hill-farmer and author of the Shepherd’s Life is very appropriate to Dartmoor as well

“Our farming way of life has roots deeper than five thousand years into the soil of this landscape. Taking my sheep down those lanes is what people have done here since the land was first settled. That is what these lanes are for, to let the little farmsteads access the mountain grazing. I am walking in the footsteps of my ancestors, and living a life they lived.”

The Reddaways ‘gathering’ their Galloways from South Tawton Common in Belstone

One man and his dog
John Jordan crossing the Teign on Gidleigh Common whilst herding his Galloways – hardcore

A little bit of soft wilding on Lydford Common

Our National Trust 10 Tors Team complete their challenge

Arms Tor across to Bray Tor

A cuckoo at Emsworthy

My friends from the Devon and Exeter Squash and Racketball Club at High Willhays

Sunset at Scorhill on the Solstice with my friend Steph

Kes Tor during the heatwave

The Tolman Stone on the Teign on Gidleigh Common with Dizzy, Nicolas and Annabelle – inappropriate footwear but all was well ….

A Highland cow near Headland Warren

A walk to Wistman’s Wood with friends

Leather Tor from Sheep’s Tor

Stand and Deliver
Widecombe Fair – The Friends of the Dartmoor Hill Ponies: the Dartmoor Hillies Warriors

Swaling on Haytor and Bagtor Common

Lunch during 10 Tors training in the rain in the Forest of Dartmoor

‘Iconic people looking after Iconic places’
Julia Aglionby Director of the Foundation for Common Land

The Gidleigh Commoners – proud people worried about their future and the condition of their Common – too much Western Gorse and Purple Moor Grass (Molinia)

Crispin Alford – a Dartmoor Commoner  who still tends his flocks and herds on horseback

Sheep gathering near Wotter – the quad bike boys

Black a Tor Copse

One of John Cooper’s Herdwicks on Okehampton Common

 

 

Gidleigh in the sunshine

Had a great 12 mile walk today  on Dartmoor today – Fernworthy Forest – Sittaford – Quinton’s Man, Watern Tor, Scorhill, Chagford Common and back to Fernworthy. By accident bumped into John Jordan herding his cattle. Love the tradition and culture of hill-farming – this time John is on a quad bike crossing the Teign at Scorhill on Gidleigh Common…. it’s a hard core life – riding quad bikes on Commons dominated by purple moor grass (Molinia) is simply dangerous… respect ..

The day the Commons came alive

Over night the Commons on Dartmoor turned green. I was at this exact spot on Thursday and the landscape was brown – a bit of rain and sunshine and the grass starts growing. A late spring but nevertheless a natural miracle. Magical Challacombe, magical Dartmoor.

When there is grass – the sheep come – I could have been standing here 900 years ago and seen the same sight. The sheep leave their in-bye (enclosed fields) and head for their summer grazing on the Commons.

Hundreds of sheep passed – Welsh Mountains and Scotch Black faces

Chivied along by two Dartmoor horse riding shepherdesses

Nearly there

Job done for another year (well, at least getting the sheep to the Common).

And right beside the drove are the rhos pastures – Dartmoor’s very, very special wet meadows – the Shire without the Ringwraithes – heaven on earth if you don’t mind wet feet. This is my favourite place on the  moor. I have spent hours and hours here over the years – it is truely magical and it never disappoints.

Marsh fritillary – one of our rarest species – I saw 20 today

And small pearl bordered fritillary – also very rare and threatened

A spider on a cotton grass flower head

The exquisite flower of the Bog Bean

What a day – epic – never let anyone tell you Dartmoor is wrecked – it is fabulous and has a history, which you can see today, going back thousands of years.

A trip to Bryher – landscapes and birds

Went to Bryher yesterday – it is such a beautiful and rugged island – here are a few pictures.

This is Shipman Head at the north end of the island

And this is Hell Bay – it takes the full unimpeded force of a westerly gale

Thift flowering beside Popplestone Bay

A maze beside Popplestone Bay

Rock sculture

Steve enjoying the view and snapping a few shots

There was a flock of four Dunlin on the Pool

They were very tame which implies they hadn’t seen people before

Birds from the wilderness

Smart bird in summer plumage

A whimbrel amongst the thrift

On its way to breed in the far north on the tundra

A stonechat

A smart male

Wrens are perhaps the commonest bird on the Islands

Bryher is well worth a visit – you won’t be disappointed.