THE NATIONAL POISONS Information Centre has issued a warning about the false widow spider whose venom is more potent than that of native spiders as temperatures begin to drop. 

It said with temperatures set to drop that the risk of encountering a false widow in the home will increase particularly around windows and in conservatories.

“The false widow is established in most counties in Ireland. It is the most common urban spider. It’s tolerance to cold temperatures, activity throughout the year and a 5-year life span make it competitive against native Irish spiders.”

It said it can produce 1,000 offspring a year and “in contrast native spiders are inactive during colder months, have shorter life spans and produce fewer offsprings.”

In a post shared on Facebook, the centre said the venom “is more potent than that of native spiders. It shares two-thirds of its venom toxin with that of a true black widow.

If you are bitten it said the severity “will depend on the spider and the sensitivity of the individual,” but a bite from a false widow is not fatal.

“Pain, redness and swelling at the area of the bite are common. Nausea, vomiting, headache, hot and cold flushes sometimes occur. Necrosis and bacterial infection have rarely been reported.”

If you are bitten it said to: “Gently wash the affected area with soap and water. Apply a cold pack to the site. Contact the NPIC, GP or pharmacist if pain persists or swelling develops. Seek medical attention for bites on or around the eye.

“Seek urgent medical advice if vomiting, radiating pain and/or hot/cold flushes develop.”

However, the centre said false widows do not randomly bite and “it’s venom is a complex resource and is usually reserved for prey, rather than humans.”

The warning comes after a new study, published in the international medical journal Clinical Toxicology, confirmed in May that some bite victims experience symptoms very similar to the true black widow spiders and some severe cases require hospital admission.

Originating from Madeira and the Canary Islands, the noble false widow spider Steatoda nobilis, now has the potential to become one of the world’s most invasive species of spider.

It was first documented in Britain over 140 years ago, but in recent decades the species has suddenly increased in numbers, significantly expanding its range and density.