Warnings over ‘severe’ false widow spider bites as numbers increase in UK

28 May 2021, 10:15 | Updated: 28 May 2021, 10:22

The number of false widow spiders is increasing
The number of false widow spiders is increasing. Picture: Getty Images

False Widow spider numbers are increasing across UK, according to a new study.

A new study claims that some false widow spider bites can cause severe reactions that could even require hospital treatment.

Research, published in the international medical journal Clinical Toxicology, says anyone bitten by the creepy crawly could suffer symptoms very similar to the true black widow spiders.

According to the Natural History Museum, the noble false widow was first recorded in the UK in the 1870s from its native Madeira and Canary Islands.

But it is only since the 1980s that the species started to grow in numbers, forming populations in the majority of the southern counties.

False Widow spiders are increasing in the UK
False Widow spiders are increasing in the UK. Picture: Getty Images

Dr Michel Dugon, head of the venom systems lab at NUI Galway and senior author of the study, said: “In addition to their medically significant venom, noble false widows are extremely adaptable and competitive in the wild.

“Two decades ago, this species was almost unknown in Ireland, the UK or in continental Europe.

“We still have much to learn about its genetics, origin, behaviour and development. One thing is certain though, this species is here to stay, and we must learn how to live with it.”

Explaining the study, postdoctoral researcher Dr John Dunbar added: “We only compiled envenomation cases where we had a clear identification of the spider responsible for the bite.

False widow spiders are often mistaken for widows
False widow spiders are often mistaken for widows. Picture: PA Images

“We had to rely on DNA extraction and genetic profiling to confirm some cases.

“We are encouraging people to capture a photograph of the spider immediately after being bitten.

“Our latest study confirms without a doubt that noble false widows can cause severe envenomations.

“This species is increasing its range and population density which will undoubtedly lead to an increase in bites.

“While most cases will have a mild outcome, we need to continue to closely monitor bites by the noble false widow to understand the potential range of symptoms and to treat severe cases when they occur.”

What are false widow spiders?

False widows are sometimes confused for black widow spiders as both have a similar dark-coloured, globular body.

The noble false widow is the largest and most commonly reported, with a body length of between 8.5 and 11 millimetres.

While there are over 650 species of spider known to live in the UK, only around 12 of these are recorded to have bitten humans.

False widows are not deadly spiders and while they do have a venomous bite, the venom is not usually harmful.

Most of the time, there will be some slight soreness and redness for between one and 12 hours, and rarely for more than 24 hours.