A noble false widow. Image: Dr John Dunbar/Venom Systems Lab/NUI Galway
The invasive spider was able to adapt its attacking behaviour to prevail in different scenarios and ate 95pc of its opponents during an Irish study.
A new study at NUI Galway has found that the venom of the noble false widow spider is 230 times more potent than other European species, which could explain its invasive spread around the world.
Originating from Madeira and the Canary Islands, the researchers said the noble false widow spider has the potential to become one of the world’s most invasive species of spider.
In recent decades, the species has spread to Ireland, as well as Europe, east Asia and both American continents.
In the new study, published in the journal Toxins, researchers investigated the false widow spider’s venom to understand why it is so successful at spreading in towns and cities throughout the world.
The strength of its venom shows it has a significant advantage against the native spider species it encounters. The researchers said this also explains how the spider can tackle much larger creatures such as bats and lizards.
Battle tactics
Over the past five years, the research team at NUI Galway’s Venom Systems Lab, led by Dr Michel Dugon, has studied a wide range of the spider’s characteristics such as its venom, ecology and behaviour.
Previous studies found that the noble false widow produces a range of toxins that are also found in black widow venom, and that a bite from the invasive species could land you in hospital.
“This study is another important step to understand the true impact this species has on the ecosystems it invades throughout the world,” Dugon said.
The researchers found that the spider can adapt its attacking behaviour to prevail in different battle scenarios.
The study suggests noble false widows make calculated decisions based on how much venom is left in their venom glands. If little venom is available, they avoid facing large opponents that could injure them and focus on small prey instead.
In a battle, the spider was shown to target specific body parts of its enemy where the neurotoxic venom is most efficient, such as the head. Over the course of the study, the noble false widow spider killed and ate 95pc of its opponents.
Study co-author Dr John Dunbar said this species is a “truly remarkable animal”, with an ability to become globally invasive and “dominate habitats it occupies”.
“The tiniest amounts of venom – about 1,000th of a raindrop – can cause medically significant symptoms in humans that are about 250,000 times larger than them,” Dunbar said. “Each new study brings us closer to understanding how exactly they are achieving their success.”
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