An expert on insects has warned of the dangers of noble false black widow spiders as two Co Waterford women have been treated for severe bites with one spending six days in hospital.
The attacks drove one of the bitten women to move to a hotel after her family home was infested by spiders.
John Dunbar, one of the main PhD researchers at the Venom Systems Laboratory in NUI Galway, says new research shows this breed of spider has now spread to 18 counties, with a big 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 having been bitten.
Speaking on Deise Today on WLR, she said she had tried to get rid of the spiders from her house for weeks before she was bitten in her sitting room, after a spider ran up the inside leg of her jeans.
When she went to hospital, Maria says she was told by staff that the bite was from a noble false black widow spiders 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,” says Maria, adding that the spider was brown with white markings on its back and roughly the size of a €2 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,” she says.
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.
Another woman who lives in Gracedieu in Waterford City said she had called in pest control to get spiders out of her house and garden a number of weeks ago but as they had already laid eggs, the spiders returned.
“I went to bed last Wednesday night and I thought everything was okay,” said Louise, mother of two.
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.
"It had bitten me on my instep. On Friday the swelling got worse and I had to go to hospital to get antibiotics.
“I got the pest-control people back and they sprayed everywhere, inside and out. It was horrendous.
"The children were very upset and I was too and we decided to stay in a hotel for the night as I couldn’t stay in the house.”
Louise said she went public with her story to make people aware of the spiders and how awful they can be.
Lead author of the study Mr Dunbar, said the false black widow spider, in addition to its venom possessing a powerful vertebrate- specific neurotoxin, can produce very strong silk which gives it a real advantage over our native spiders in entangling large prey.
He called for more research to be carried out.
“I am currently researching the venom in particular,” he said, “and it takes 500 spiders to get just one raindrop size of venom for research purposes.
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.”