Easter Sunday walk along the river Wear

Probably the best weather that I can ever remember for an Easter Sunday. We took a walk along the south side of the river Wear, between Wolsingham and Black Banks plantation at Harperley.

Reassuring to find that the weird flower spikes of toothwort Lathraea squamaria were coming up again under the old coppiced hazels, where we've known them for nearly 40 years.

There's something vaguely reptilian about these parasitic flowering plants that siphon off all their nutrients from the roots of hazel.

You can read more about the strange physiology and folklore of toothwort by clicking here.

This is the plasmodial stage of the slime mould Reticularia lycoperdon [recently renamed Enteridium lycoperdon], probably only about a day away from turning into the sporulating stage. In the plasmodial stage it creeps over the alder tree trunk surface, digesting bacteria, then it forms a parchment-like skin (for pictures click here) enclosing countless dark brown spores. When the skin ruptures they are dispersed on the wind, then germinate into minute amoeba-like organisms that eventually aggregate back into this creeping plasmodial stage, which is most often seen in spring.

I found my first wild primrose of the season growing at the base of an ash tree, and ....

... hundreds of butterbur flower spikes had appeared along the riverbank in the last week.

Elm flowers. A mature elm tree in full bloom was a wonderful sight, with its crown a haze of purple, but it's one we are unlikely to see again, thanks to Dutch elm disease. Young elm trees that have regenerated from the roots of dead stumps are common enough though.

The beautiful juvenile female cones of larch, waiting to be pollinated.

Artefacts of autumn: a hazel nut neatly split in two by a grey squirrel and the stone of a fruit (wild arum?) nibbled by a field mouse.

A rather tatty peacock that had safely made it through the winter and was sunbathing on an old plastic bag.

A pair of goosander on the river. Their behaviour changes in spring. A few weeks ago they would have flown before I could get close but once they are paired up and have identified a hollow tree to nest in they are reluctant to leave their territory.

A fantastic carpet of wild garlic leaves beside the footpath, that will become a sea of white in a few days' time when the flowers open.

Those trees at the top of the bank host a rookery, so we were accompanied by their cawing along this stretch of the walk.

Dive! Dive! Dive!

This beautiful drake goldeneye was at Tunstall reservoir near Wolsingham in Weardale this afternoon.

also, 

..... a flight of oystercatchers ... and ...

... very wary great crested grebes that are likely to nest here..

.... and singing chaffinches in the alders all around the reservoir

Boletus

I found this beautiful bolete amongst the old oaks in Backstone Bank wood, near Wolsingham in Weardale, this morning. Think it might be an oldish specimen of the cep or penny bun Boletus edulis, judging by the whitish edge to the cap - but not sure.

Pine cone bug

Found this lovely little pine cone bug Gastrodes grossipes scurrying around below some Scots pines, near Wolsingham in Weardale today. 

The adult bugs overwinters in a secure spot and mate soon after emergence in spring. The nymphs that hatch from the eggs feed on the soft tissues of pine - especially the developing green cones, and reach maturity in early autumn.

Adult bugs often shelter between the open scales of mature pine cones.

Longhorn beetle

I noticed this head peeping over the handrail of the footbridge .....

.... across Thornhope beck, near Wolsingham in Weardale, last Sunday. It quickly retreated under the rail ....

....... but turned out to be this very handsome two-banded longhorn beetle ....

..... which goes by the name of  Rhagium bifasciatum. Its larvae feed inside decaying conifer wood.

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.