Daniel Greenwood

The language of leaves

Posts from the ‘Insects’ category

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Thursley Common, Surrey, June 2018

I’ve recently moved somewhere new and with that comes an interaction with new landscapes. In the United Kingdom, a distance of 25 miles can open up entirely new experiences in the outdoors through the sudden change in soils, topography and local culture. I have moved further south into Sussex, in touching distance of a tangled web of counties (West Sussex, East Sussex, Surrey and Hampshire), communities and habitats. One landscape that feels closer than it ever did is lowland heathland, a landscape I’ve come to learn more about in recent months.

I now know that dry lowland heath has been drastically lost over the past 150 years and it is rarer than rainforest. It is a human-made habitat with intrinsic ties to a pre-industrial way of life where local people grazed their animals, cut and burned heather, extracted sand, cut trees, but were unable to grow crops due to the poor fertility of the soils. It is subject to epic conservation projects in some places, like the Heathlands Reunited project working across the South Downs, tipping into Hampshire and Surrey in places outside the South Downs National Park.

My family have roots in Ireland and I have spent time there learning about the way of life of people who lived in the wild and very wet western areas. To my ancestors heather was an incredibly diverse resource. It could be cut at the right age to produce all manner of items, most fascinating to my mind were lobster pots weaved from woody heather growth.Β The subsequent cutting of heather allowed new growth and light to reach the heathland, benefiting many different species – denser growth for ground nesting birds, increased flower abundance – and a mosaic of vegetation lengths which further the species diversity through the creation of micro-habitats.

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With the popularity of the rewilding movement in the UK, heathlands are a point of contention because an argument for landscapes to be left to ‘adopt their natural state’. This is at odds with the desire to see heathlands humanised again, what is shown to produce the richest conditions for their wildlife. Heathlands which are ‘left’ or ‘rewilded’ become simply poor quality woodland in the sense of the lack of species diversity.

One site stuck in that tangled-web of counties is Thursley Common, a National Nature Reserve managed by Natural England in Surrey. I visited Thursley for the second time in June on a hot but mercifully breezy day. There were many thousands of dragonflies on the wing – so many I declined to ‘tick off’ the vagrant red-backed shrike which people were heading over to see but completely ignoring the riot of OdonataΒ  – and the sandy paths were brimming with rare insect life.

Having visited Thursley a year before with a tour from the site manager, I had an idea of where the good stuff was and some background on their ecology. Over the winter I had looked forward to returning to try and photograph the heath sand wasp and mottled bee-fly. Thankfully the weather was perfect for this.

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Kneeling down on a sandy track it was possible to see the heath sand wasp, found only on lowland heath, mainly in the south of England. It was caching moth larvae that it had been hunting out in the heather. It’s hilarious how they use a small roll of sandy soil to close their doorway before heading off again to hunt on the heath.

They have every right to be cautious. Lying in wait on tiny scatterings of twigs were mottled bee-flies, a rare insect that parasitises the nest of the sand wasp. It wasn’t clear whether the sand wasp was wary of me or suspicious of the presence of the fly (do insects experience suspicion?) but at times the bee-fly deigned not to move, creating a kind of stand off between the two insects as the sand wasp waited to fly off to hunt and the bee-fly waited to hover and throw its eggs into the hole.

Sure enough, after the wasp had moved away, the bee-fly was hovering over the nest hole, chucking its eggs in like a footballer volleying the ball into an open goal.

These are two species which, without managed heathlands (interestingly much of the management they benefit from is the result of footfall exposing sand along the paths) would be lost. Woodland’s return would mean a loss of light, warmth and resultant heather growth where the sand wasp’s prey is found, meaning that the structure that binds these species would collapse.

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Another unusual insect along the paths was the hornet robberfly. This is another type of fly that can be found in heathland and is classified as rare. It is possibly the largest fly in the UK but it looks like a hornet. Like many of our flies (bet you don’t consider them your own) it mimics the appearance of a predatory wasp to give a greater sense of protection. In terms of natural selection, it has survived probably because it looks like a species that has a world-shattering sting at the tip of its abdomen.

Robberflies do exactly what their name suggests, they steal insects and eat them, sucking them dry in about thirty minutes in the case of the hornet robberyfly. The best way to see them is through a macro lens and to hang out somewhere that you know has lots of other insects present. Some stunning photos are out there with robberflies holding on to their fly prey.

I spotted the hornet robberfly because it was sitting on a pile of manure, exactly where it likes to spend its time in life. It was using the manure as a perch to hunt where it can blend in with the hay stems that a horse or cow can’t quite digest. They also lay their eggs in the crevices of the dung.

It was a privilege to see these rare species, unseen to almost everyone (obviously), only present because of good management and an appreciation that human impacts can be positive for living things other than ourselves.

 

 

 

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Nomada rufipes

Nomada rufipes, a cleptoparasitic bee that I spotted on Farthing Downs on the edge of London. It steals from an Andrena bee to survive, but I only saw it drinking nectar from the heads of these ragwort flowers.

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Swanscombe Marshes, August 2015

The Swanscombe marshes are threatened by an impending planning application by London Paramount. They want to build a theme park on this vast wildlife haven. Is that really the best use of wild land when wildlife is in severe decline in Britain? I don’t think it is. I visited Swanscombe in March and have written this poem. There is a petition by a locally-led campaign to save the marshes, please sign it if you like what you see here.

Swanscombe

Swanscombe has a number of different habitats: reedbed, brownfield, hedgerow, woodland, farmland and species rich brownfield grassland.

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The grasslands along Black Duck Marsh are covered by wild carrot, birds-foot-trefoil, kidney vetch, red clover and a number of other nectar rich plants. This has attracted a number of interesting insects which have seen flower rich meadows and waysides disappear over the past 50 years. The insect above is an ichneumon wasp, one of over 2000 species in Great Britain.

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It’s unusual to see early bumblebee around in August, but here one was, feeding on hawkweed oxtongue, a weedy plant that provides a great deal of nourishment for invertebrates at this time of year.

Turnip sawfly

Turnip sawflies were seen across many of the flower heads of wild carrot, a common plant at Swanscombe. Sawflies are lesser known pollinators related to bees and wasps.

Painted lady

Sited alongside the Thames, it was not surprising to find a few migrant butterflies. There were a number of clouded yellow (too quick and unsettled for me to photograph) and this painted lady. It was fresh and may well be readying for its amazing journey south through Europe to North Africa where its parents had set off on their journey in the spring. How they can find their way back is not yet known to science.

On the southern slope of the rocky bank that runs through Black Duck Marsh, lucerne grew in large clumps. Even on a grey and breezy day there were a number of butterflies there. This, however, is a day-flying moth, the latticed heath.

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There were patches of kidney vetch growing along the rocks of the Black Duck Marsh bank, and we wondered if small blue, a very rare butterfly in Britain that relies on the plant, could be present. We didn’t see a small blue but I did find this common frog hopper, the insect responsible for what I knew as a child to be ‘cuckoo spit’.

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Common blues were flying low in the grass, possibly laying eggs on birds-foot-trefoil.

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The breeze made macro photography very tricky, but I tried to make the most of the grey sky, wild carrot and lacewing feeding on its flowers.

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Sitting on the bank of Black Duck Marsh we were visited by this stunning hornet mimic hoverfly, Volucella inanis. This insect is in the family Volucella, a group of hoverflies which mimic bees and other Hymenoptera (bees and wasps) in order to deter predators and instead fool them into thinking they’re a threat.

Brownfield is a poorly understood habitat, it is also in the firing line as the housing crisis intensifies in the south of England through lack of affordable housing and poor planning in central London (I’m referring to the luxury accommodation, property banking boom), to name but a few symptoms. As for its importance to wildlife, willow tit is a severely declining bird in England but is now seemingly favouring brownfield over ancient or more established, secondary woodland. Brownfields are often so rich because, like Swanscombe, they are free of pesticides and are left to establish of their own accord. Many brownfields are more precious and indeed green than parts of the Green Belt, a measure ordained to protect open space. They’re also pointers to the feeding opportunities that non-native species like the above white melilot can offer to native insects like bees, a group of insects that offer Β£560million to the UK economy through pollination (Bumblebee Conservation Trust).

The Channel Tunnel could be heard as it raced underneath our feet. The above photo is the largest spread of birds-foot-trefoil I have ever seen, all growing on the spoil from the original development of the tunnel. Again, brownfield habitats can be some of the richest in Britain. This area would be lost to the development.

There were a number of pathways cutting through the marshes, like this buddleia byway.

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My single memory from visiting Swanscombe Marshes in August will be the colour of the grasslands, the yellow of the trefoil, the white of the carrot and purple and blues of the lucerne. Please sign the petition to raise awareness about this unique and diverse wild place. There is time to make a difference and Save Swanscombe.

See more at the campaign page for Save Swanscombe Marshes

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Painted lady, London, August 2015

Fifteen minutes in the garden or a green space (or brown space) is all that’s needed to complete the Big Butterfly Count. My fifteen minutes were sumptuous. Not only did a painted lady remain for far longer than the allotted time, but a common blue appeared for the first time ever in my garden. This was the second new sighting locally in two days. Patrick Barkham has written that a hot August will help them. Do have a go, you’d be amazed at what you might see. You have until the end of August. Hanging around buddleia is advisable if you’re competitive.

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