Grey wagtail

Grey wagtails are balletic birds, never still for an instant, always twirling and darting here and there in search of insects. I photographed this beauty in the river Tees, downstream from Abbey bridge at Egglestone. The river is fast and turbulent there, rushing through a narrow rocky gorge, and its spray encourages luxurient growth of mosses and liverworts at the water's edge - a favourite feeding ground for wagtails in search of small insects that live in this riverbank vegetation.

 

No ladybirds for months, then five species all at once.....

Thursday's Guardian Country Diary describes encounters with ladybirds in Weardale and Teesdale.

Back in the spring it seemed as though 2013 might be a good year for ladybirds locally - plenty of 7-spots seemed to have come out of hibernation so I anticipated a thriving population by the time their offspring hatched in summer - but it never seemed to materialise. I found a few isolated individuals of other species - notably 22-spot , 14-spot and an orange ladybird  but then last week .........

........ this huddle, near a pine plantation at Wolsingham in Weardale. It was the largest number of 7-spots I'd seen in one place all year: six that had chosen a split in a fence post as their hibernation site. 7-spot ladybirds aren't usually associated with conifer plantations but his particular row of fence posts, on the sheltered, south facing side of the plantation, as always been a good place to find other species. 

So it was no surprise to find this eyed ladybird - a conifer specialist - sunning itself on the same line of fence posts.

A small, unidentified fly with unusual up-turned antennae had even chosen to hitch a ride on it. The eyed ladybird is our largest species but ...

...... this one, a larch ladybird that shared the same fence post, is one of our smaller species ...

..... here going head-to-head with a staphylinid beetle (which it simply head-butted out of the way!)

Then, a day later at Egglestone in Teesdale I found ivy in full flower that had attracted several orange ladybirds, that were feeding on nectar.

You can see here the translucent pronotum of this species, that used to be considered scarce but seems to have increased in abundance in recent decades, supposedly because it has taken to feeding on fungi that grow on the honeydew secreted by sycamore aphids. On one occasion a few years ago I found a cluster of ten of this species hibernating on the bark of a sycamore in winter - it's certainly a species that can be added to the very small number of insects that are associated with sycamore, which has been present on these islands for around 500 years but has a very small insect fauna.

Close to the orange ladybirds on the ivy I then found a single 7-spot sunning itself on a fence post and ......

.......... scores of this very unwelcome addition to our ladybird fauna - the harlequin. The first time I saw these locally was in Durham city back in 2009, on ivy flowers at almost exactly this time of year. Harlequins are noted for their bewildering range of colour patterns but the indentations at the tail end of the elytra are also a distinctive feature, although they too vary in extent between individuals.

This group of about a dozen individuals had just hatched from their pupae and were still developing their full colours. Harlequins have a breeding season that extends well into autumn.

Some, that also seemed to be the most rotund individuals, were almost entirely black ...

..... but his was a more typical colour pattern in this population.

Finding another population of harlequins was an unwelcome discovery because this disease-resistant species is known to be a predator of our native ladybirds and can also transmit a parasite that kills other species. It also feeds extensively on eggs of butterflies and moths. Over the last decade it has spread rapidly from south east England to the Scottish border. It originated in central Asia but was introduced elsewhere in misconceived biological control programmes aimed at 'environmentally friendly' aphid control in greenhouse crops. Wherever it has been introduced it has escaped and has had a detrimental effect on native insect populations.

The predominantly black individuals seem to have blue eyes.

This was the last unhatched pupa, attached to the fence posts. At the point of attachment you can just see the remains of the larval skin, which is spiny in this species. 

Harlequin larvae also seem to have an affinity with sycamore, perhaps because of the vast supply of sycamore aphids that they find on the leaves - so it may well be that orange ladybirds will also form part of their diet too.

If you find harlequin ladybirds you can report their presence by contributing the record to the Harlequin Ladybird web site.

An Autumn Walk along the River Tees

The long, narrow gorge spanned by Egglestone's Abbey Bridge bridge provides one the most picturesque viewing points on the River Tees in autumn

This is the view from the bridge looking upstream - Egglestone Abbey is just  above the trees in the middle distance (double-click) and is ...

...... visible from the bridge now that the leaves are falling.

The view downstream - there are footpaths on both sides of the river and you can follow it down to its confluence with the River Greta, at the Meeting of the Waters.

The river squeezes through narrow gaps and tumbles over boulders ...

.... and you can hear it through the trees all the way along the path, even when it isn't in spate.

The high humidity in the gorge makes this a fine habitat for mosses and ferns like this polypody growing as an epiphyte on a tree branch over the river.

Yellowing horse chestnut leaves provide a sunbathing spot for flies whose days are numbered, now that frosts are on their way.

Nectar-rich ivy flowers provide a last-minute refuelling station for drone flies.

Shades of yellow - hazel, oak and beech autumn colours.

Some of the large beeches have been attacked by honey fungus - always fatal, but it can take decades to kill the tree.

A nuthatch, dangling down to pick beech nuts out of beech mast - it seems to be a 'mast year', with a very heavy crop.

Ripe holly berries are a reminder that there are only 50 shopping days until Christmas.

Downstream there are some wild cherries with a fiery display of autumn colours..

... and a fine crop of ripe yew berries.

A passing shower leaves a rainbow, which is wasted on those two sheep that are watching - they only have dichromatic vision and can't distinguish red from green.

Looking back upstream - on what Kenneth Grahame in the Wind in the Willows called a 'golden afternoon'...