Saturday, April 30, 2016

Frog-bit Hydrocharis morsus-ranae

When I was a kid in the 1950s nuclear power was the wonder of the age and the exploits of the nuclear submarine USS Nautilus, which was the first of its kind to traverse the North Pole underwater, was big news in the school playground.

To celebrate the event Kellogs cornflakes produced little plastic models of the submarine, that you could acquire by sending off a small fee and a tab from the packet to the manufacturers. You needed to fill the hollow submarine with baking powder, then it would sink and surface again when the baking powder became wet and released carbon dioxide bubbles. 

Kids were enjoyed simple pleasures in the pre-digital toy age.

The little plant in this photo emulates the actions of a submarine. It's frog-bit Hydrocharis morsus-ranae and it produces resting buds called turions that sink to the pond bottom in autumn then rise again in spring, like a surfacing submarine. 

The plant gets its name from the shape of those leaves which resemble that of a frog's mouth.

I've never seen frog-bit growing in the wild (it's very rare here in Durham) but several years ago I went into a shop in Leeds and found that they were selling the plant for indoor aquaria. I introduced it into my pond and it thrived alongside the frogs for a short while. A few turions rose to the surface again in the second year but after that it died out. I suspect that it was overwhelmed by dead leaves on the pond bottom or duckweed on the surface. 

Finding these old photos reminded me of the episode, and of the cornflake submarines. I notice that a few nurseries advertise the plant for sale so I might get hold of some and try growing it in a small aquarium. I wouldn't mind finding one of those toy submarines to play with too, for nostalgia's sake!

Thursday, April 28, 2016

Eric Ennion

Eric Ennion (1900-1981) is primarily remembered as a brilliant bird illustrator, whose combination of observational, drawing and water-colour skills produced pictures of birds that are full of energy and are uniquely graceful. But he also illustrated a few books on other forms of wildlife and one such was this .....

Life in Pond and Stream by Richard Morse, first published by Oxford University Press in 1945 and revised in 1950. 

Ennion set out on a medical career but his love of wildlife and artistic skills drew him towards natural history illustration. At the time that he illustrated this book he had just left his medical practice to become Warden of Flatford Mill Field Studies Centre and was enjoying the first public exhibition of his paintings at Ackermann Galleries in London.

You can read more about the man and his paintings at

His illustrations for Life in Pond and Stream show all the hallmarks of an artist whose work was informed by first-hand observation. The book has fifteen plates - here is a small selection. 

Natterjack toad;kingcup;edible frog;common frog;butterbur;common frog;common toad

Great crested newts; smooth newt; palmate newt

Perch; pike;roach; dace; bream; eel; freshwater mussel

Raft spider; bladderwort; water spider; water boatman

Freshwater shrimp; freshwater louse; Cyclops; water flea; crayfish

It's well worth hunting down this delightful little book in second-hand bookshops.

Monday, April 25, 2016

Bee-fly - every mining bee's worst nightmare?

I photographed this bee-fly Bombylius major on a sunny bank neat Thorsgill wood in Teesdale last week.

These furry little flies that mimic bees are parasites of mining bees and several of them seemed to have just emerged from their underground nursery in bees' nests.

Their first actions on emergence are to feed on nectar, darting from blossom to blossom with incredible speed, rarely stopping to settle and usually just hovering in front of a flower, sucking up nectar with that long and deadly-looking proboscis.Violets and primroses, both flowering at this site, are popular nectar sources. 

Few flies look so menacing but they are totally harmless - unless you happen to be a mining bee.

When mining bees dig their new tunnels and provision them with pollen for their developing larvae a bee-fly will hover close to the ground near the entrance,flicking eggs into the tunnel entrance with its tail. When the eggs hatch the larvae will eat the mining bee host's own larva.

You can find more information, a bee-fly ID guide and a video of the insect laying eggs at

Friday, April 22, 2016

The Amazing Eyes of a Green Lacewing

We found half a dozen of these green lacewings fluttering against the window of a bird-watching hide at Low Barns Nature Reserve yesterday. They must have hibernated in there. We let them all go but before that I took a few photographs, because these common insects can be surprisingly hard to spot in the open.

They have the most beautiful gauzy wings and eyes like jewels but their colour varies depending on the way that they are lit.

The two photos above are with the camera's built-in flash but ....

... this one is with natural light. Notice how the spots on the abdomen show up so much clearer with this illumination. Flash can sometimes conceal important identification features, which is one of the reasons why identifying insects from photos can be tricky ....

Flash can also create strong reflections from shiny surfaces, like the wings of this insect, that are folded over the body like a tent.

Perhaps the most striking fetaure of these insects when they are photographed with flash is their eyes, which resemble glowing red, green and yellow jewels. In natural daylight they seem to be golden but with flash internal reflection and refraction within the separate lenses of the eye create this multi-colour starburst effect.

Lacewings, in the larval and adult stages of their life cycle, are great allies for the gardener, consuming large numbers of aphids. This is a lacewing egg, on a long stalk on the underside of a hawthorn leaf, with the larva just hatching.

 It is a voracious greenfly consumer, impaling its prey on powerful jaws and they carrying around the empty skin of its victim on those hairs on its back. There are some pictures of one, resembling a miniature walking compost heap, here.

Saturday, April 16, 2016


We found this delightful little snail, just 16mm. long, on  a dead tree in Thorsgill woods in Teesdale recently. 

It's called Clausilia dubia, according to the excellent  Field Studies Council ID guide for land snails.

Tuesday, April 5, 2016


This little silverfish Lepisma saccharina had a lucky escape last night when I rescued it in the nick of time from our bath. It lost a few segments from one antenna and from its tail cerci, but was otherwise intact - and very lively.

I hadn't seen one of these tiny, pewter grey, carrot-shaped wingless insects for quite a while. When I was a kid I used to see them racing out of dark corners of the kitchen cupboard, with their body undulating like a fish.

They like to feed on carbohydrates like spilled flour or sugar – the clue is in the saccharina part of their Latin name – and they also thrive on starch-based glue that holds some cardboard cartons together.

Silverfish like cool, humid places but their slightly larger and less common cousin, the firebrat, needs heat. It has lived alongside humans for as long as we have heated our homes with fire and was once common in bakeries. My grandfather, who worked for a major bakery firm in the 1920s, once told me that it wasn’t uncommon for them to be picked up in the dough and accidentally baked into loaves; not something that would earn Mary Berry’s approval in The Great British Bake Off.

These are some of the most ancient insects on Earth. Catch one, take a look with a magnifying glass and you’ll see that its carrot-shaped body is covered with these minute, overlapping, iridescent silver scales. These are easily shed and, together with their fast, wriggling motion, have allowed these living fossils to evade the jaws of predators for over 400 million years.

Saturday, April 2, 2016

Golden Saxifrage: alternate- or opposite-leaved?

There are some spring woodland wild flowers that are so common and widespread that they are barely noticed amongst the showier species like primroses, bluebells and wood anemones. One such is golden saxifrage   .........

..... seen here growing beside Thorsgill near Egglestone Abbey in Teesdale.

Initially I thought this is the very common opposite-leaved golden saxifrage but when I posted this picture on Twitter one keen-eyed observer, @Feldbotanik, pointed out that at least some of these plants are the much rarer alternate-leaved golden saxifrage, which I have never seen before. Both species sometimes grow together. I must go back for a closer look!

This is usually the first of the woodland wild flowers to bloom and when it does it really lights up the shady, stream-side habitat that it favours. It creeps across the surface of boulders and fallen trees, forming a dense mat of flowers.

If you search through wild flower books they'll have almost nothing to say about this near-ubiquitous plant apart from a general description of the species and its habitat, despite the fact that it grows almost everywhere except the intensely farmed eastern counties of England. 

There seems to be no folklore and herbal medicine attached to it and it only has two local names (according to Geoffrey Grigson's The Englishman's Flora) - creeping Jenny (in Sussex) and buttered eggs (in Wiltshire). 

Grigson also mentions that in the Vosges it is eaten as a salad under the name of cresson de roche, but apart from that no one seems to have anything much to say about it.

Its flowers are, though, a very welcome sight in the earliest days of spring. They are surrounded by leafy bracts, but ....

... the actual flowers are very small. There are 8 stamens but no petals - those yellow, rounded petal-like structures are sepals. A small pool of nectar, which you can see glistening here, collects in the centre of the flower and attracts the attention of fly pollinators as soon as they emerge in spring.