This fly needs a new name

By Una D'Arcy

Is it possible that humans are quite simply the least interesting animals on the planet? Take the Caddisfly for instance, we should campaign to get it a much cooler name. On Saturday morning in Fore, I was introduced to my first Caddisfly, which looked remarkably like a small pebble. Thankfully Cathal Flood, LAWPRO (Local Authorities Water Programme), and Ross Macklin, aquatic ecologist, were there with the science.

They were in Fore to disturb our macro-invertebrates, small aquatic creatures, happy in the gravel on our stream beds until we kick up their stony grey waterbed so we can have a better understanding of water quality. Then we count these little larva, snails, worms and beetles – all just about visible to the naked eye.

Ross, in wellies and a buoyancy vest, carried out the kick sample, giving the inhabitants a rude awakening, and Cathal carried out the less wakey wakey, nutrient test. The event was part of Biodiversity Week and was funded by Waters and Community and LAWPRO.

If the stream was unpolluted, there would be a great variety and abundance of invertebrates, but where a river has excessive amounts of nutrients and other pollutants, the numbers and types of macroinvertebrates are usually lower and many of the rare and sensitive species are absent.

Getting back to the not so catchy Caddisfly, whose larval stage turned up in our sample; it looked for all the world like a pebble because they make themselves little cases to live inside by spinning together stones, sand, leaves and twigs with a silk they secrete from glands around their mouths. I cannot think of a single interesting thing humans do that beats this.

“They create a ballast,” said Ross to those gathered for the Biodiversity event, “so they fall to the bottom of the stream.” These little constructors can be identified by what they choose to enrobe themselves in, some of them spin sand, others weave plants.

It is just extraordinary and the two lads handle these tiny invertebrates with the same care and respect you see David Attenborough extend to orangutans and dolphins.

Caddisfly change from living with actual pebbles in the spinning streams to emerge as moth-like creatures, “but their wings fold back along the body and they have a fine set of hairs on their wings instead of scales”, said Ross. At that, you nod sagely because you are starting to understand that really, everyone should know how to distinguish a moth from a Caddisfly.

So now you’re a fan, you can refer to Caddisfly as moth-like aquatic insects then throw in the aul Latin like you read Cicero before watching Kin – they are ‘Order Trichoptera’.

A most efficient predator was also present in the water sample drawn from the spring-fed stream that is the source of the Glore. Its compact, muscular body, well-developed nervous system and efficient sense organs drew it towards us like a set of miniature Giger nightmares; little leeches all over the stone. I checked it was a stone by saying, so this is not Caddisfly, to which the two scientists looked at me like I was something you might find in a kick sample. Cathal summoned patience and said, “no, that is in fact a stone”. But interestingly, in the way that many things are super cute when they are tiny, leeches are not.

Then there were the aquatic nymphs of plecoptera, the stonefly that love a cool, highly oxygenated stream and in turn are much loved by trout.

Some of these lads have gills where their legs attach to their bodies, invertebrate armpits so to speak, so you see them doing push-ups to move water past their gills. And there was Mayfly. So if we do campaign to get a new name for caddisfly – stonefly and mayfly are already taken,

Spending an hour with Cathal and Ross was like being the company of John Muir himself, the conservationist who said “When we try to pick out anything by itself, we find it hitched to everything else in the Universe.” To watch as little as 200mls of water reveal the entire life of the valley of Fore was astonishing.

Ross and Cathal will be back during Heritage Week in Fore – please keep an eye out for more information.