Horse stingers, eye pokers and Devil's darning needles

ANOTHER LIFE:MATSUO BASHO, 17th-century Zen master and inventor of the telegraphic haiku, certainly got the colour right, but the slender red damselflies sunning themselves on glossy acanthus leaves beside our pond were probably better drawn in the old rural name of "Devil's darning needle".

Still, the fact that the Japanese delight in the huge numbers of dragonflies and damselflies that emerge from their flooded paddies, regarding them as symbols of courage, strength and happiness, and that Europeans in general can’t wait to think up derogatory names – “horse stinger”, “eye poker” and so on, neither with any justification – marks very different cultural attitudes. In Japan – once Akitsu Shima, the Dragonfly Isles – even manhole covers can be decorated with odonata, and communities without paddies dig dragonfly ponds to encourage them.

Tinsel-bright red damselflies, earliest to emerge in spring, are surely small enough not to alarm, and a pair mating on a lily pad shape one of the more charming diagrams of insect Kama Sutra. But the large, strong-flying hunters among dragonflies emerging later in the year can certainly inspire some awe in their whirring passage past one’s ear.

Those that let you stalk them with a camera are likely to be darters, species that hunt territorially from a fixed position, dashing up to seize a passing prey and returning to perch again. One of these, on the wing now and commonly noticed by weekend walkers, is the stocky four-spotted chaser – often surprisingly noisy as it spars with rival males, wings clattering off leaves around a pond, or moorland vegetation.

Far more wary are the hawkers, patrolling territorial beats up and down, perhaps beside a stream or canal. They watch with enormous compound eyes with up to 30,000 facets. A body structure that has changed little in more than 250 million years enables aeronautic skills that must be the despair of any helicopter designer. With long abdomen as rudder, and separate control over each set of wings, the dragonfly can flick itself in all directions, even backwards, and swivel its head to look underneath or behind. When it spots its prey (wasps included), it makes a net of its spiny legs and scoops it out of the air.

Until 10 years ago, the biggest and brightest blue dragonfly among our 24 resident species was the male common hawker, ranging widely over moorland, high up the hills and even out to islands. But climate change has now brought us the powerful and spectacular blue emperor, flashing like a kingfisher as it holds sway over a whole pond or stretch of shoreline.

First spotted by birdwatchers on the Wexford coast in 2000, it has colonised Ireland as far north as south Armagh and into Limerick and Clare in the west.

The blue emperor is one of four Odonata species that have arrived in Ireland since 2000, part of a wider movement of Europe’s southern species as climate change dries out available wetlands. This is noted in a new publication, a Red List evaluating threats to Ireland’s odonata, published by the National Parks Wildlife Service (npws.ie/publications/redlists/RL6.pdf). It is based on almost 32,000 records of the island’s resident damselflies and dragonflies, and the particular experience of Brian Nelson and Robert Thompson in their recent four-year Dragonfly Ireland survey.

While the Mediterranean dragonflies are losing their habitats through water demand and scorching summers, Ireland’s abundant wetlands face a more familiar menace: eutrophication of ponds through run-off of farm fertiliser or pollution from septic tanks.

Ireland may lack the great variety of species of central Europe, or even as many as Britain, but it does have a few special ones well worth conserving. Rarest and most threatened are the downy emerald, northern emerald, crescent bluet and small bluetail, all adapted to living, as immature underwater larvae, in wetlands low in nutrients and vulnerable to enriching pollution. A fourth, the robust spreadwing, is Ireland’s rarest damselfly, hatching mainly from the ephemeral waters of farmland turloughs in the west.

So far, as the new report points out, no species of dragonfly or damselfly has legal protection in Ireland, but Northern Ireland's new Wildlife and Natural Environment Bill will offer it to Coenagrion lunulatum– the crescent bluet/Irish bluet/Irish damselfly – discovered in Sligo by the ecologist Don Cotton in 1981. It is absent from Britain but found quite widely across Ireland.

Eye on nature

On a back road near Strandhill I spotted a single male greenfinch among a flock of goldfinches. It was the first I've seen since their collapse four years ago. Is this a sign of some recovery or just a chance survivor?Brendan Morrissey, Strandhill Road, Sligo

Greenfinches suffered an outbreak of trichomoniasis, caused by a parasite that blocks the bird’s throat, killing it by starvation. Improved hygiene at bird baths and feeders may have halted the spread of the problem, and populations should have started to revive from survivors.

Watching hooded crows dropping mussels on to the rocks at Irishtown Nature Park recently, I was surprised to see a crow with an overshot hooked beak, rather like a bird of prey.Tom Curtis, Fitzwilliam Quay, Dublin 4

A green slime has appeared in my frog pond. I am told that tadpoles feed on algae, so I have not removed it.Malachy Daly, Killadoon, Co Mayo

New ponds are very likely to have an algal bloom that is actually consuming the excess nutrients in the water. Give the pond time to balance itself, and add some pond plants, such as water lilies, water hyacinth and submerged pond plants, which will absorb nutrients.

* Michael Viney welcomes observations at Thallabawn, Carrowniskey PO, Westport, Co Mayo, or e-mail viney@anu.ie. Please include a postal address