AN EXPERT ON insects has warned of the dangers of Noble False Black Widow spiders after two Waterford women were treated for severe bites – with one spending six days in hospital.

The attacks, which were first reported on local radio station WLR, took place in the last two weeks and caused one of the women to move to a hotel in fear because her family home was infested by spiders.

John Dunbar, a PhD researcher at the Venom Systems Laboratory in NUI Galway, told the station that new research shows that the spider has now spread to 18 counties, with a significant concentration in Dublin and along the east coast.

Maria Condon from Ferrybank spent six days in University Hospital Waterford after large blisters formed on and underneath her leg within minutes of her being bitten.

Speaking to Damien Tiernan on the Deise Today programme, Condon said she had tried to get rid of the spiders from her house for a number of weeks before being bitten in her sitting room, where a spider ran up the inside leg of her jeans.

She said that she was told by hospital staff that the bite was from a Noble False Widow spider, as she had captured it under a glass and had taken pictures of it.

“Staff said it was the worst such bite they’d ever come across from a False Black Widow,” she said, adding that the spider was brown with white markings on its back and roughly the size of a two Euro coin.

“I wasn’t aware at the time of how serious the infection could turn out but I ended up in hospital for six days after what seemed to be three bites in total.”

Laid eggs

Noble False Black Widow spiders are not uncommon in Ireland or Britain but none were recorded here before the 1990s.

Experts believe their numbers are on the rise as a result of global warming, and they have previously been observed feeding on Ireland’s only native terrestrial reptile, the Viviparous lizard.

Another woman who lives in Gracedieu in Waterford city said she called pest control to remove the spiders from her house and garden a number of weeks ago, but revealed that they managed to return because they had laid eggs.

“I went to bed last Wednesday night and I thought everything was okay,” she said.

“Suddenly in the middle of the night I woke up with an awful pain in my foot. I knew something had bitten me.

“I threw back the cover and turned on the light and saw this thing run down the sheets and down over the end of the bed.

“I didn’t know where it had gone and my foot was very sore and it got worse on Thursday. It had bitten me on my instep. On Friday the swelling got worse and I had to go to hospital to get antibiotics.

“You’d never expect this in Ireland – you’d never expect to be bitten by a spider and have to go to hospital or whatever.”

Describing the experience as “horrendous”, the woman also revealed that she had to leave her home to stay in a hotel for the night because she felt she couldn’t stay in her house.

Potential bacteria development

Noble False Widow spiders are remarkably adaptable and possess fast-acting neurotoxic venom that can cause neuromuscular paralysis in terrestrial vertebrates.

John Dunbar of the Venom Systems Laboratory in NUI Galway has said that the False Widow spider can also produce very strong silk, which gives it an advantage over native spiders in entangling large prey.

He called for more research to be carried out, and said he is currently researching the venom of the spider in particular.

“It takes 500 spiders to get just one raindrop size of venom for research purposes,” he said.

“We are looking at the potential for bacteria to develop after bites and we are finding all sorts of activity in the venom but more research is needed.

“From hearing the stories of the women in Waterford, I do believe they were bitten by Noble False Black Widow spiders.”