Black Jumping Spider bites – a danger to Tenerife residents and a mystery
Are Jumping Spiders harmless?
Jumping spiders are usually regarded as harmless to humans. They are small spiders that live on walls and other flat surfaces and catch their prey by jumping, hence their name.
There are countless species around the world and none are listed as dangerous in books, on websites and in information sources apart from in message boards and forums in Tenerife in the Canary Islands.
Residents of the island say that a small black jumping spider can bite you and that if bitten you may end up in hospital. Clearly this is a very important matter but the mystery is why are there no warning in books or on websites about jumping spiders?
Another mystery is what species of jumping spider or spiders is causing a danger to people by biting them? No one seems sure but they all claim that the spiders are black or jet black and some say they are like tiny crabs or have crab-like pincers.
Allergies and allergic reactions to spider bites
It is known that some people are allergic to spider bites and that they can suffer a very bad reaction if bitten but this does not explain why so many people in Tenerife say they have terrible reactions to the bites of these spiders. Surely the island isn’t full of people with spider allergies?
There are plenty of websites that will confirm that allergic reactions can occur to jumping spider bites but none of these sites claim that the spiders are regarded as any real danger. Some sources go as far as saying that it isn’t true that jumping spiders bite and that the creatures are harmless.
This cannot be correct due to the sheer number of reports on Tenerife, and many of these reports say that the victim of the spider bite had to see a doctor or even ended up in hospital.
Jumping Spider bite poll
Have you been bitten by a Jumping Spider?See results without voting
Symptoms of the jumping spider bite
Those that say they have been bitten by black jumping spiders say that there are two small bite marks and that the area around the bite can really swell up. Some say that a limb may even become paralysed and it can take days or even a week before the swelling goes away..
The area by the bite can become red and inflamed and may itch a lot but it is not recommended that you scratch it because this can make things much worse.
Many say that they are left with scars after being bitten by such a spider.
Macaroeris nidicolens (WALCKENAER, 1802) - ♂ - jumping spider
Treatment for Jumping Spider bites
People in Tenerife say that you need to see a doctor right away if bitten by a jumping spider. Antibiotics are one form of treatment.
It has been said that the spiders cause an infection in the wound and that the flesh may even become necrotic unless treated.
Tenerife Jumping Spiders
There are several species known on the island and the most likely culprit appears to Macaroeris nidicolens judging by descriptions of the appearance of these spiders. It is a blackish spider and may have white markings on its back. Many of the reports say that the black jumping spiders that bite have a white dot or cross on the back.
Macaroeris nidicolens is listed and illustrated in the book Historia Natural de las Islas Canarias by David Bramwell and Zoe L. Bramwell but it doesn’t say anything about these spiders being venomous.
According to Wikipedia the species is found in Europe and Asia but surprisingly if this is the spider that is biting people there is no warning about it and no reports anywhere else.
Perhaps it is some other species then but what species? Nobody seems to know but then most people are not spider or wildlife experts!
Macaroeris nidicolens (WALCKENAER, 1802) - Female - jumping spider
How do people get bitten by spiders?
Now admittedly many people who claim to have been bitten say it happened when they were asleep so didn’t actually see the spider but they point to the evidence of the puncture marks from the bite and how small black jumping spiders live where they are.
It is possible that the spiders have bitten people who have rolled onto them whilst sleeping, and also that victims have sat on spiders or put their hand, leg or arm on one. Spiders will bite if pressure is put on them. It is a natural form of defence.
However, some spider bite victims claim that the spiders jumped on them and attacked them. This is not known of as a form of behaviour from jumping spiders though the spiders are curious and will jump on you but not to bite and attack you. Normally these tiny spiders will run or jump away.
So what is going on here? What species of jumping spider is biting people on Tenerife? It is a real mystery!
© 2013 Steve Andrews
More by this Author
Ensign Wasps are small black insects that look a bit like spiders with wings. They do not sting but are useful because they kill cockroaches.
The spider known to science as Steatoda grossa is otherwise known as the False Black Widow and the Cupboard Spider. I have two here living predictably in a cupboard in my apartment here in Tenerife in the Canary...
Very many British people, and other nationalities too, come to Tenerife, or want to come to the island, thinking it will be easy to get work there. A lot of these people also have grand dreams of running their own...