Although generally not lethal, the bite of the indigenous arachnids can cause severe allergic reactions, leading in some cases to hospitalisation. A leading entomologist at Nottingham Trent University believes the impending UK heatwave could cause an explosion in their numbers. Dr Christopher Terrell-Nield told The Sun: "The warmer it is, the more insects you tend to get, their life cycles are shorter, they become more active.

       “And the same, of course, happens with the spiders.

       "Everything gets sped up. Instead of the offspring taking, say, four months to emerge from an egg sac, they might only take two months because of increasing temperature."

       The noble False Widow derives from Madeira and the Canary Islands.

       It was first reported in Britain over 140 years ago - in the 19th century.

       According to a recent study from the National University of Ireland Galway, the false widow has "become one of the most common species of spiders found in and around urban habitats," in some parts of Britain and Ireland.

       The report's authors are unsure as to why numbers are increasing so rapidly.

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       However, they suspect the rise could be the result of a genetic mutation, enabling the species to be "more adaptable to new environments."

       As numbers increase, chances of being bitten by the spiders also rise.

       Symptoms of a False Widow bite can range from "mild to debilitating pain and mild to intense swelling" in addition to "tremors, reduced or elevated blood pressure, nausea and impaired mobility," according to the Science Daily.

       Tracey Hamilton, 50, recently had to receive treatment in hospital, after being bitten twice by a False Widow.

       She was told that she might even need surgery to prevent the spider venom from spreading into her bones.

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       Ms Hamilton, who is from Scotland, told the Glasgow Times: "After blood had been taken they told me a plastic surgeon would be round to see me - I gasped, I thought they had gotten me mixed up with another patient.

       "My legs were jelly and all of sudden it hit me it was serious and I felt helpless.

       "I thought it was midge bites - how wrong I was."