Thursday, October 29, 2009

Weeping Widow?

Steve Ansdell, Durham University’s Horticultural Superintendant, showed me this spectacular display of toadstools in the grounds of Josephine Butler College today.

There must have been well over a thousand of them, spread over an area the size of a football pitch. By far the finest display of toadstools I've seen so far this autumn. They fit the description of Weeping Widow Lacrymaria velutina.

The caps of the young specimens had a distinctly fibrous appearance and the microscopic characters fitted the text-book description for this species.

Dark brown gills becoming increasingly black with age and, although it's not too evident in this specimen, wisps of the fibous veil that covered the gills in the young toadstool still clinging around the edge of the cap....


....and a distinctive black spore print

For a microscopic exploration of this fungus, take a look at

Wednesday, October 28, 2009

Sunbathing Survivors

With the first hard frosts probably no more than a couple of weeks away, insect numbers will soon plummet but for now, during what I believe has officially been declared an ‘Indian Summer’ by the Met Office, there are still quite a few around. This parasitic hymenopteran, which I think is a male Gasteruption jaculator, was feeding on a late-flowering hogweed umbel this afternoon. The crane fly (below) had arranged itself decorously over a yellowing Norway maple leaf, soaking up the weak afternoon sunlight.

Monday, October 26, 2009

Season of Mouldy Fruitfulness

A few days of mild, humid weather has produced some fine displays of moulds and rust fungi on fruits and leaves that are reaching the end of their useful lives. This bramble is afflicted with both diseases – Botrytis mould consuming its rotting fruit and the rust fungus Phragmidium violaceum producing some beautifully colourful effects on its ageing foliage. There’s a peculiar kind of beauty to be found in decay.

Pristine bramble fruits, before Botrytis fungus found them.....

Friday, October 16, 2009

Life's a Beech

This autumn the upper surface of many of the leaves on young beech trees around here are carrying these cylinrical, hairy galls caused by a midge called Hartigiola annulipes that laid its egg in the leaf surface back in the spring. Opening them up reveals the hollow chamber inside with the larva developing down at its base. In a week or two, when it's mature, the gall will separate and fall from the yellowing leaf, shortly to be buried under a carpet of fallen leaves. The larva will pupate there, until the adult midge emerges in spring, at just the right time to lay its eggs in the soft tissue of a newly expanded leaf.

Gall sectioned vertically.....inside, there's a large, hollow chamber

The larva, tucked in here down at the bottom of the gall chamber, still has plenty of room to grow.

Tuesday, October 13, 2009

Drinking in the Last Chance Saloon

Just when most of our flora finishes flowering, ivy comes into bloom and provides a last-minute autumnal energy top-up for insects like this drone fly (below, feeding on ivy pollen) and red admiral (above, drinking nectar), before the frosts arrive. To appreciate why its flowers are so attractive to insects, you need to take a really close look on a mild humid morning, when the disc at the centre of the flower is absolutely swimming in secreted nectar (see lower two photos) and newly open stamens are still full of fresh yellow pollen. It’s difficult to underestimate the value of this plant as an energy source for insects that hibernate, bearing in mind its wide distribution, the vast number of flowers produced on just a single plant and their long flowering period.

Freshly opened ivy flowers, oozing nectar and laden with pollen.

Wednesday, October 7, 2009

Honeybee in Disguise

The first time I saw one of these bees with a distinctive band of white hairs along its thorax I spent some time leafing through field guides unsuccessfully trying to name it – until I realised that it was a honeybee that had been feeding on Himalayan balsam flowers (see When the bee pushes its way into this flower to reach the nectar the hairs on its thorax pick up white pollen from the stamens that are in the roof of the floral chamber. As it backs out it brushes the stamens away exposing the stigma, ready for the next pollen-laden visitor to the balsam flower to deliver its stripe of pollen to the sticky stigma. I've also seen wasps with tell-tale white thoraxes which have evidently been collecting nectar from the same source. I photographed this ‘striped’ honeybee today on wild carrot, after it had exited the Himalayan balsam flowers nearby.

Monday, October 5, 2009

The Alien that Conquered Britain

The conker season is here again – amply celebrated today in an article in the Times newspaper (see Horse chestnut Aesculus hippocastanum is our best-loved alien species which, during the 400 years since it was first introduced into Britain from the Balkans, has graced our parklands and become the focus of a traditional sport that has left generations of school-kids nursing aching knuckles after misjudged swings of an opponent’s conker.

The seeds of horse chestnut are truly exquisite objects. Their deep umber hue has given its name to a colour and their glossy texture contrasts wonderfully with the spiky husk that they are enclosed within. Sadly, it’s a beauty that doesn’t last – after a day or two those glossy seeds become leathery and lose their rippled patterns. In the USA Aesculus species are known as buckeyes, on account of the resemblance between those glossy brown orbs and the eyes of deer.

I may be wrong, but I suspect the horse chestnut seed is the largest amongst trees in Britain. They invest a lot of resources in giving their germinating seeds the best possible start in life, by providing them with a very large food store.... but at the expense of long-distance dispersal (take a look at for a completely different plant seed dispersal strategy).

One of the perils of producing seeds with a large food store is that they simply become food for hungry animals (think of all the acorns that are guzzled by squirrels, jays and wood pigeons) - which may be why conkers contain high levels of toxic substances called saponins which are natural detergents and generally damaging to animal digestive systems. Ground-up conker flesh can provide a deterrent against slugs, which have a strong aversion for saponins and tend not to cross a barrier of conker meal. This might be the basis for a natural method of slug control, but for the fact that saponins are water soluble, so that any attempt to use them as slug deterrents would be washed away in the first shower of rain.

Saturday, October 3, 2009

Spare a chip, gov'nor?

A mooch around Tynemouth flea market, followed by a stroll along the Tyne, watching the birds and the ships, finishing at North Shields fish quay for a fish-and-chip lunch is a fine way to spend a Saturday morning.

There’s something about windy days like today that seems to make crows exceptionally vociferous, and this was one of several croaking and cawing from the white popular trees planted beside the Tyne between Tynemouth and North Shields. The fish quay at North Shields is famed for its fish and chips and this local population of crows has opted for the easy life, swooping down to hoover-up chips dropped by passers-by. They face stiff competition from the seagulls, but crows’ inherent craftiness seems to ensure that they manage to make a good living with minimal effort, even if this diet is sending their cholesterol count sky-high.

This one broke off its raucous chorus for a minute to peer down at me in case I had a spare chip.

Thursday, October 1, 2009

Toxic Toad

I found this tiny toad – a juvenile that’s developed from one of this year’s toadpoles – sheltering under a stone in the company of two slugs that were substantially larger than this bite-sized amphibian.

Baby toads like this are not as vulnerable as they look, because their skin secretes a foul-tasting poison that deters most potential predators. Just behind the eye, on either side of the head, there’s a dense area of poison-secreting tissue concentrated in the parotid glands, which are clearly visible as paler, elongated swollen lumps with prominent pores in this alarmed youngster.