In an effort to introduce a shaft of sunlight into a particularly gloomy conversation, I recently asked a gardening acquaintance of mine to explain the difference between a slug and a snail.

For the next twelve minutes and seven seconds, this horticultural monomaniac held forth on the most minute and inconsequential differences between gastropod molluscs with rudimentary or no shells and gastropod molluscs with well developed spiral or whorled shells. When he finally ran out of breath, I swallowed hard, took three precautionary steps backwards, and told him that a slug is a snail that can't afford a mortgage.

Instead of smiling as I had done when I had first unearthed this daft definition in a dog-eared copy of 'The Readers Digest' (dentist's waiting room edition), he ground his dentures together, cracked his calloused knuckles, and growled so raucously that the button almost exploded from his collar.

He went on to catalogue in some detail the manifold acts of vandalism perpetrated by these 'horticultural thugs' who, he said, spend their entire daylight hours skulking plumply under stones, ruminating darkly on last night's grim destruction and this night's planned assaults.

He proceeded to ridicule the 'green-wellied wimps' who nightly sprinkle little handfuls of slug pellets around vulnerable flowers and vegetables; and the poor drunkard who meanders home each night clutching a bottle of beer with which to entice and drown the occasional slug foolish enough to mistake his little beer traps for hospitality vats.

'I have suffered enough from the same blasted slugs over the years without starting to buy drink for them,' he said. 'There's only one answer to those brutes...all out military action!'

His eyes grew incandescent with malevolent glee as he described his nightly sorties into the flowerbeds and lettuce patches where, armed with a commando style torch and a jumbo-sized barrel of table salt, he would venture forth in search of the enemy.....a lethal avalanche of sodium chloride cascading inexorably on the masticating molluscs ?

'O little slug thy hapless play my thoughtless hand has swept away.'

'I have suffered enough from the same blasted slugs over the years without starting to buy drink for them,' he said. 'There's only one answer to those brutes...all out military action!'

Grinning maliciously, he described in graphic detail a fiendish plan, which he had been working on in the privacy of his horticultural bunker. I cannot recall the preliminary tactical manoeuvres, but remember that they culminated in him leaping gymnastically from the top of a hawthorn hedge and landing squarely on an unsuspecting black slug just as it was about to devour an equally unsuspecting French marigold.

Chilled to the marrow by his demonic laugh, I suddenly remembered that I had parked on a double yellow line. So, wishing him well, I vaulted over his rustic fence and fled.

On my way home, I pictured him somersaulting and cartwheeling hysterically among the broad beans and the brassicas as he celebrated each decisive victory over those diminutive moonlight marauders.

While walking through our local market some months ago, I caught sight of a particularly ostentatious display of French marigolds. Acting on impulse, I purchased three dozen and planted them out that evening. On the following morning I went out into the garden to admire the results of my debut as Capability Brown Mark 11.

Would you believe it? My proud marigolds had vanished! Yes, totally! All except three pathetic looking survivors with broken necks and tattered stems. On closer inspection, I discovered the unmistakable, tell - tale slime trails leading triumphantly into the adjoining hedgerow. As one gardening writer described them: "The obscene graffiti of a night's destruction... adding insult to injury."

Apoplectic with rage, I was looking around for something to kick hard and often when suddenly, through the thick black smoke and suffocating stench of mental cordite, I conjured up the image of my gardening friend with his beaming torch and his gigantic barrel of table salt.

"Then seek your job with thankfulness and work till further orders, If it's only netting strawberries or killing slugs on borders."

With these inspirational words of Kipling ringing loud in my ears, that night I too joined the ranks of the horticultural storm-troopers and sallied forth armed and ready to slug it out with that ghastly gardening gastropod : The Slug.

'Slugging It Out In The Trenches' is taken from 'Apples on a Sunny Shelf'. See: http://www.assignmentsplus.com/garden-pests.html

Gerard McLoughlin, Director of Assignments Plus Publications http://www.assignmentsplus.com, is the author of 'Apples on a Sunny Shelf', a collection of essays first broadcast by Radio Television Eireann (Ireland's national broadcaster) on the popular 'Sunday Miscellany' series.