Daily Archives: June 4, 2012

Insects and molluscs

Over the last couple of weeks I’ve been out and about photographing wild flowers, and of course the raison d’etre of flowers is to produce the reproductive cells of the plant in order to ensure survival. And as plants are immobile they rely on other vectors to connect the male and female parts, that can be the wind and the rain but many flowers are exquisitely evolved to attract one or more species of insect to carry the pollen to the ovum and effect fertilisation.

So in the course of photographing the flowers some of them were hosting a pollinator or two:

Tree bumble bee – Bombus hypnorum

This tree bumle bee was sipping nectar from the flower of the white deadnettle. It’s one of the insects that is strong enough to get to the back of the flower and take the nectar. Flowers have evolved in this way such that the insects have to pass the stamen, which is where the pollen, or plant sperm, is produced. The stamen is made up of the filament and the anther, and foraging insects brush against the anther picking up pollen which they carry to the next flower where it is deposited on the female part of the plant – the ‘carpel’, and fertilisation ensues.

There are various species of bees in the UK but only around half a dozen common ones. Bees are in trouble in this country and no one seems to know why, both honey bees, which live in colonies, and solitary bumble bees are dying out at an alarming rate.

Buff tailed bumble bee – Bombus terrestris

The buff tail above was in a particularly poorly condition and had tiny mites crawling on it’s body so I imagine it didn’t do much more pollinating.

Soldier beetle – Cantharis rustica

The soldier beetles are related to the fireflies and they get their common generic name from one species which is bright red and is therefore named after the ‘redcoats‘ – English soldiers from days of yore. The larvae and the adults are carnivorous, the larvae feeding on insect eggs and caterpillars and the adults on aphids. They also feed on nectar and can therefore pollinate too.


Black slug – Arion ater

Alot of people have an aversion to slugs because of the damage they can do to fruit and vegetables, but this chap was out in the field making a meal out of a couple of dandelion seedheads. I don’t think they contribute much to pollination and they are predated by frogs and toads and also hedgehogs. Although I’ve heard that if too much of a hedgehog’s diet consists of slugs, parasitic worms living in the slugs can get into the lungs of the hedghog and kill it because its lungs fill up with fluid. Which sounds pretty unpleasant but I guess it’s not the fault of the poor old slug!


Brimstone moth – Opisthograptis luteolata

The brimstone moth is a splendid creature with a wingspan of 32-37 mm. It’s common and widespread across the UK. In the warmer climes of  the southern UK there can be three generations in a year but in the north there is only one brood per annum, and adults can be seen on the wing between April and October. The caterpillars feed on various trees and bushes including hawthorn and blackthorn.

A couple of weeks ago after days of rainfall which had moistened everything I found a 50m stretch of verge which was crawling, literally, with hundreds of yellow and brown snails.


Brown lipped snails – Ceppaea nemoralis. Just a few of the hundreds that were making the most of the damp conditions

The ‘lip‘ of the snails in their name is the front edge of the shell which can be seen in the next two pictures and is lighter brown on the yellow one and a much darker brown on the brown one:

Snails are predated by songthrushes. They pick up the snail by the fleshy part and crack the shell on a handy stone. Some years ago I was sitting at home on my own reading a book and everything was very quiet. I heard ‘tap tap tap’ on the front door, but when I went to answer it their was no one there. So I went back to my book. A few mintes later I heard the same tapping and again there was no one there, so I opened the door to have a look up the street and rather than a visitor there was a collection of broken snail shells on my front doorstep. It transpires the tapping I’d heard was a songthrush using my front doorstep as an anvil to swing the snails against and hammer open the shells!

Advertisements

More blooming flowers

Hedgerows, field borders and roadside verges continue to thrive in this part of the world as a result of the recent rainy weather. Nettles are in abundance at the moment, in particular the white deadnettle (Lamium album):

The white deadnettle is, as the name suggests, not a stinger, and it’s common all over the UK, Europe and Asia. It’s white or pink flowers need to be prised open in order to reach the nectar at the back of the flower so only bulky insects such as bumble bees can reach it. It flowers from March to December so it can provide a food source for these insects for most of the year.

According to the Royal Botanic Gardens at Kew, the leaves and flowers can be eaten raw when they are young and tender and the fresh leaves can also be boiled and eaten as a vegetable. The flowers can also be boiled in water and used as a traditional herbal remedy for catarrh and dropsy, which is another name for oedema, or build up of fluid under the skin. The roots can be boiled in wine, which will extract compounds that are insoluble in water into the alcohol fraction of the wine, and the resulting concoction can be used as a remedy for kidney stones. White deadnettle is also used as a herbal treatment for benign prostate hyperplasia, which is enlargement of the prostate gland, and for gastrointestinal problems. So this humble hedgerow plant has the potential to provide a plethora of therapeutic compounds.

The white deadnettle is also known as bee nettle, blind nettle, day nettle, deaf nettle, dog nettle, snake flower and white archangel.

And the other nettle which is springing up everywhere is the much maligned stinging nettle, Urtica dioica:

The flowers of the stinger are tiny and green and grow in strings which are several centimetres long. The stinging mechanism is via hairs, or ‘trichomes‘, and each one has a bulbous end that breaks off when brushed by a passer by, leaving a sharp hollow tube. The tube acts like a tiny hypodermic needle that injects a cocktail of irritant chemicals including histamine and acetycholine which potentiate an inflammatory immune response which is the cause of the stinging sensation. The sting protects the nettle from grazers but also offers protection for other species which are resistant to the sting and the stinging nettle is therefore home to various species of insect and is an important refuge for caterpillars such as that of the peacock butterfly. Before slashing them down in your garden see if you can’t find an out-of-the-way corner to let them grow and provide a home for the butterflies.

Cooking the nettle leaves removes the sting and they are rich in vitamin C so they are used to make soup, herbal tea and, latterly, pesto and in the production of a cheese called ‘yarg‘ from Cornwall.

Charlock, Sinapis arvensis

The yellow flowers of the charlock plant, also known as carlock, corn mustard, field kale, kedlock, kerlock, kinkle, wild kale and wild mustard, have sprung up along the field-side drainage ditches and hogweed, Heracleum sphondylium, is well established too:

Hogweed flowerhead

Hogweed grows all over Europe and flowers from June to August. The flowers burst out of large pods at the top of the stems and are initially pink but fade to white. The young shoots are reputed to be good to eat with a flavour similar to asparagus and the plant gets its name because it was gathered to provide feed for pigs in times past. Hogweed is also known as cow parsnip, cadweed, clogweed, eltrot, giant parsnip, madnep and meadow parsnip.

Pansy, Viola arvensis

Lurking along the edge of the nearby rape fields, almost hidden in the undergrowth, are pansies. The name of the pansy originates from the French word ‘pensee‘ – thought. It is also know as heart’s ease, ladies’ delight and stepmother’s flower.


Hedgerow cranesbill, Geranium pyrenaicum

Hedgrow cranesbill, aka mountain cranesbill, is very common at the moment. It flowers from May to August and it gets it’s name from the shape of the seedpod in some species of geranium which is long and pointed and said to resemble the beak of the crane.

Herb bennet, Geum urbanum

According to the RHS herb bennet also has a number of colourful names: blessed herb, city avens, clove root, colewort, Indian chocolate, minarta, St Benedict’s herb, star of the earth, water flower and wood avens. This plant grows in shaded spots and flowers from May to August. It has aromatic roots which have been used to flavour ale and give off a smell of cloves so it was hung by the door to ward off evil spirits. It was also used medicinally by the Romans as a substitute for quinine.

My day job is in the pharmaceutical industry so I have a professional interest in chemicals which could have medicinal applications either on their own or as cocktails of compounds which may be contained in the same plant. So when I’m researching a post like this I wonder how many species we’ve lost due to modern agricultutal practices and how much herbal knowledge and potential drug molecules have passed into history. Many have probably been lost but there are still thousands remaining to provide us with food, herbs and spices, medicines, and to add the wonderful shapes and colours to the countryside.