The ‘Daddy Long-Legs’ may appear meek and mild, but it can devour larger spiders

Ella McSweeney: A new course from the National Biodiversity Data Centre is a calming antidote to exaggerated and inaccurate media reporting about spiders

The Pholcus in the bathroom may appear meek and mild, waiting for prey to be caught in its web, but it can devour larger spiders using a mix of deception and force. Photograph: Arterra/Universal Images Group via Getty Images
The Pholcus in the bathroom may appear meek and mild, waiting for prey to be caught in its web, but it can devour larger spiders using a mix of deception and force. Photograph: Arterra/Universal Images Group via Getty Images

It’s that spidery time of year, and in the corners of my bathroom ceiling, a large six-eyed female Daddy Long-legs (Pholcus phalangioides) hangs motionless upside down and appears so dainty, translucent and spindly that she’s almost invisible. She’s positioned herself well, opposite the open window, so if the lights are left on during the night, moths will fly in and find themselves caught in her messy, dishevelled web. They’re a tasty mouthful, no doubt.

During this mating period, spiders emerge from the dark recesses of our buildings. The males are searching for a female mate, and it can be a rather frenetic few weeks for them. Things will settle down within the first few weeks of October when the season ends.

The Pholcus in the bathroom may appear meek and mild, waiting for prey to be caught in its web, but it can devour larger spiders using a mix of deception and force. To do this, it takes the initiative and leaves in search of another spider’s web. As it enters the web, it will vibrate to mimic a trapped fly, and this causes the unsuspecting owner to scuttle out. At this point, the Pholcus will throw silk from its long back legs and entrap the spider before biting it with paralysing venom. Like nearly all spiders, it’s harmless to humans; this deadly drama plays out with creatures of a diminutive kind.

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It’s also the time for Giant House Spiders (Eratigena atrica) to appear. Up close, they’re an attractive deep auburn colour with a humbug-patterned body. The male has exceptionally long legs which help it to move at a Usain Bolt-like pace. If you spot one, you’ll see its comically bulbous sex organs hanging out in front of its face like a pair of miniature boxing gloves. It’s here, in these “palpal bulbs”, that the male stores sperm.

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The males wander around scouring for females in dark places such as under sofas, bookcases and beds. She’s a sedentary homebird who spends her time in her self-built home, made of sheets of horizontal silk with a tubular retreat in the corner. (It’s a remarkably robust structure which, if left intact, will be used by generations of spiders over the years.) Once the male finds her, they’ll mate, and he’ll then loiter nearby to deter other males from getting near. It’s all a bit exhausting, and within a few weeks he’ll die; if the female needs a snack, she’ll eat him before overwintering with his stored sperm, ready to produce eggs in the spring.

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If, like 11 per cent of the world population, you struggle to relax around spiders (arachnophobia is one of the most widespread animal fears), you might be charmed into submission by a free online course from the National Biodiversity Data Centre, which was developed by Collie Ennis of the Zoology Department at Trinity College, Dublin.

We have something to gain from sharing our spaces with spiders, given that they will gorge on pesky household creatures we’re not so keen on

The harmless Giant House Spider is, says Ennis, “very gentle”. The male of another species, the Nursery Web Spider, found in damp meadows and along our coast, will offer his female mate a nuptial gift of prey to stop her from eating him. Then there’s the charming black and white Zebra Jumping Spider, found around tree trunks and on garden furniture. Ennis writes that it spins a single silk thread, like a bungee cord, before pouncing on its prey. If the male wants any chance of romance with a female, he must perform a John Travoltaesque dance, gyrating his hips and legs before she allows him to do the deed and insert his palp into her abdomen.

Ennis’s course is a calming antidote to exaggerated and inaccurate media reporting about spiders. Last year, researchers analysed over 5,000 global news stories on spiders, published between 2010 and 2020, and found that 47 per cent of the articles had errors and 43 per cent were sensationalist, frequently using words such as “deadly”, “terrifying”, “horror”, and “poisonous”, even though just 0.5 per cent of spider species – there are 50,000 of them worldwide – pose a severe threat to humans (and of these, nearly all live in habitats where humans are absent).

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Nearly all of our 380 species in Ireland are entirely harmless to us, so we have little to fear. In fact, we have something to gain from sharing our spaces with spiders, given that they will gorge on pesky household creatures we’re not so keen on, like carpet beetles, woodlice, fleas, bedbugs and houseflies.

And before you decide to whoosh that elegant Daddy Long-legs away, spare a thought for its most helpful habit: it will hunt and eat the False Widow Spider, a non-native invasive species which has spread to nearly all counties in Ireland since it was first spotted one evening on August 13th, 1998, wandering around a house in Bray, Co Wicklow.

Ella McSweeney

Ella McSweeney

Ella McSweeney, a contributor to The Irish Times, writes about the climate crisis and the environment