A new species of poisonous spider was discovered in Portugal, more specifically in the city of Porto. This is the Chilean recluse spider, known scientifically as Loxosceles laeta, and this is the first confirmed record of the species in the Iberian Peninsula.
The discovery was made by researchers from the Museum of Natural History and Science of the University of Porto and published by .
Despite the species being poisonous, experts rule out alarm scenarios. José Manuel Grosso-Silva, an entomologist involved in the research, explained that the probability of a person coming across this spider or being bitten by it is reduced.
The species is shy and not likely to bite.
According to the study cited by Euronews, the Chilean recluse spider is a shy species and is not likely to bite. Still, their bite can cause considerable damage to the skin, including necrotic skin lesions.
The species is native to the western region of South America, being found in countries such as Brazil and Argentina, but has managed to reach other regions through international trade.
First specimens found in Porto
The first specimen was discovered by chance on September 10, 2025, in a wall in Campo dos Mártires da Pátria, in Porto.
The second was found on January 10, 2026, already dead, in a sticky trap that had not been placed to capture this spider. The two identified specimens were males.
The researchers admit that it is not yet possible to know whether the Chilean recluse spider exists only in Porto or whether it is already more dispersed.
One of the difficulties lies in the fact that this species can be confused with the Mediterranean recluse spider, the Loxosceles rufescenswhich has existed in Portugal for several decades.
The two species are similar in appearance and behavior, being brown, discreet and more active at night.
They live in hidden places
Unlike other spiders, these species do not make the more visible webs that are commonly found on plants. They prefer walls, corners and hidden or shadowy places.
The reliable identification of the Chilean recluse spider is mainly through the males’ pedipalps, structures located on the front part of the body.
Bite can cause necrosis
The risk to the population is considered low, but researchers recognize that bites from this type of spider can have different levels of severity.
In more serious cases, loxoscelism may occur, a syndrome caused by the venom of these spiders.
In 2023, Portugal recorded a case associated with the Mediterranean recluse spider, involving a 48-year-old woman bitten while in an urban park.
Case in Portugal required hospitalization
In this case, published by the scientific journal SPMI Case Reports, the woman was bitten on the back of the head and began to experience swelling without immediate pain.
Over the next 24 hours, the symptoms worsened, with headaches, malaise, feverish sensation, tiredness and necrosis in the area of the injury.
The patient was discharged from hospital 16 days later, without symptoms.
The presence of this spider in Portugal also raises questions about the arrival of new species in the country.
According to researchers, more than 300 species of insects from various regions of the world are established in Portugal, many introduced through the transport of goods.
Increased trade, changing habitats and rising temperatures can favor the arrival and expansion of exotic species.
Situation will be monitored
In Europe, the Chilean recluse spider had already been recorded in Finland, in 1972, and more recently in Germany, in 2025.
There are also references to the possible presence in Italy, but this record remains to be confirmed.
In Portugal, researchers emphasize that it will be necessary to monitor the evolution of the species in the coming years, to understand whether its presence in Porto is isolated or whether it can expand.
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