Home North America Mexico Spiders In Mexico: 7 Venomous, Large, And Unusual Species

Spiders In Mexico: 7 Venomous, Large, And Unusual Species

spiders in mexico
Photo by Ekamelev on Unsplash

If you’re wondering if there are many spiders in Mexico, the answer is definitely yes. There are over 2000 different species of spiders living there. But before you swear off ever visiting the country, remember that the vast majority of those are tiny arachnids that pose no threat to humans and which you don’t need to worry about. 

There are only three spiders in Mexico that are venomous enough to be harmful to humans and only a couple of other species big enough to cause concern. And then there’s one little one that just has a rather unfriendly defense mechanism!

We’ve listed the 7 biggest, most dangerous, and most unusual spiders in Mexico here so that you’ll know what to expect – and what to avoid – when you visit. 

Black Widow Spider

The Black Widow spider's venom is dangerous to humans
Photo by Charaj on Wikicommons

Arachnophobes might not want to hear it, but the venomous Black Widow Spider has an extensive range. It lives on every continent except Antarctica and can often be found in Mexico. They favor quiet, disused spaces such as garages, woodpiles, outhouses, and sheds. They will sometimes make their webs inside houses under furniture or the underside of window sills. 

Because of their poor eyesight, they perceive both prey and possible threats by feeling the vibrations in their webs. So it’s wise to be extra cautious in potential widow habitats. Despite their fearsome reputation, Black Widow Spiders are not aggressive and do not actively attack humans. They will only bite if startled or feeling threatened, and bites usually occur when humans come upon them or their webs by accident. 

If you’re unlucky enough to be bitten by a Black Widow Spider, don’t panic but seek medical care immediately. The venom can cause muscle pain and spasms, intense abdominal cramps, excessive sweating, rapid heart rate, and shock. The majority of bites are not deadly but in rare cases, mostly when the person bitten is is a child, elderly, or already unwell, they can be fatal.

Brown Recluse Spider

the Brown Recluse Spider is the most dangerous in Mexico.
Photo by Timothy Dykes on Unsplash

The Brown Recluse is also known as the Fiddleback or Violin Spider due to the shape of the markings on its back. It is the most dangerous spider in Mexico and is well known for the unpleasant effects of its venom. A bite from this spider is not immediately painful and often goes unnoticed by the victim. However, soon after, they may begin to feel nausea, fever, joint and muscle pain, and respiratory distress. The venom also causes necrosis, where the soft tissue around the bite wound festers and dies. This can cause large, spreading lesions and deep wounds, which risk getting infected and sometimes require surgery. 

If left untreated, the spider’s bite can lead to organ failure, amputation of the bitten limb, and death. As with the Black Widow, the effects are often more severe if the person bitten is a child, elderly, frail, or unwell. If you suspect a bite by a Recluse Spider, seek immediate medical assistance, because delaying treatment can greatly increase the severity of the case.

Luckily the Recluse is a rather shy spider – hence its name – and avoids contact with humans. It makes its web in quiet, seldom used places like storage rooms and old boxes. However, it also nests inside unworn clothing, shoes, and bedsheets. Most bites happen when humans put on their clothes or get into bed and accidentally press the spider against their skin. So, while in Mexico, make sure to regularly check your clothes, shoes, and bedsheets for spiders.  

Hobo Spider

The Hobo Spider is often mistaken for others.
Photo by Judgeking on Wikicommons

The Hobo Spider is the third of our highly venomous spiders in Mexico. Luckily, like the Black Widow and the Recluse, they are rarely aggressive towards humans and only bite when threatened. In addition, the danger posed by the Hobo Spider is now up for debate. 

The Hobo Spider’s venom was once said to have the same necrotic properties as the Recluse Spider. But it is now thought that this was a case of mistaken identity. The Hobo Spider has a nondescript appearance. It can be various shades of brown and has no distinct markings. So given its similar appearance to the Recluse Spider, this led to one often being mistaken for the other, causing the incorrect necrotic venom rumors. 

But, it’s still best to avoid this spider as its venom is toxic and can cause numbness and swelling of the bitten limb. The wound may weep or discharge fluids, and the victim may suffer severe headaches. The symptoms may be worse if the victim suffers an allergic reaction to the venom. 

Due to the risk of misidentifying this spider, we recommend seeking medical assistance if bitten and, if possible, catching the spider responsible and taking it with you. This will help doctors identify the level of danger and help them treat the bite effectively. 

Mexican Wandering Spider

The Brazilian Wandering Spider is a close relation of the newly discovered Mexican Wandering Spider.
Photo by João P. Burini on Wikicommons

Mexico’s biggest spider caused a stir back in 2013 when the previously unknown species was discovered living in a cave and old mining shaft in Baja California Sur, Mexico. While discoveries of new spider species are a fairly regular occurrence, it’s rare for such a large specimen to have gone unnoticed for so long. This one has legs up to 10cm long and visible red fangs, prompting the media to run wild with stories of massive fanged spiders being discovered in Mexico. And causing many people to swear never to enter a cave ever again.

It took the scientists four years to fully classify the spider, but eventually, they announced that it was indeed a new species and officially named it Califorctenus cacachilensis. Also known as the Sierra Cacachilas Wandering Spider, named for the mountain range in which it lives.

The spider is a close relation to the notoriously deadly Brazilian Wandering Spider, but luckily for Mexico, it is nowhere near as dangerous. One of the scientists who discovered the spider was bitten in the process and described it as painful (unsurprising given the spider’s fangs) but said it had no adverse effects. Further investigation into this new spider’s toxicity, habits, and behaviors is still underway.

Red Kneed Tarantula 

Mexico's tarantula population is under threat by the pet industry
Photo by Tamara Gore on Unsplash

Mexico holds second place for the most tarantula species in the world, after Brazil. There are estimated to be a whopping 66 species of tarantulas in the country. However, since few people dedicate their time to seeking out and documenting the different species, there may be several more as yet unidentified. 

Mexico’s tarantula population is also declining due to the actions of the exotic pet industry. Wild tarantulas are regularly trapped and smuggled out of the country to be sent to the US, Chinese, and European pet markets. The Red Kneed Tarantula is one of Mexico’s most common and sought-after species, desirable for its striking appearance, long life span, and docile nature. 

When left in the wild, the spider lives in forested areas where it makes burrows under rocks and tree roots to hide from predators and await passing prey. It isn’t aggressive, hence its suitability as a pet, however, if severely provoked or threatened, it can give a painful but not dangerous bite. Like most tarantulas, it can also defend itself by firing spiky hairs from its abdomen at its attacker. These hairs can cause mild irritation or allergic reactions in humans, especially if they get under the skin or in the eyes. 

Wolf Spider

The Wolf Spider is found all over Mexico
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Wolf spiders are a hardy, adaptive species that can be found living in a variety of habitats across Mexico. They can live in forests, fields, coastal regions, farmland, and homes. They can dig burrows like the Red Kneed Tarantula and wait for passing prey, or they can actively hunt and chase it down. They are agile and fast, have excellent eyesight, and are prodigious hunters. 

For this reason, some people don’t mind having them inside their homes because they effectively keep down the numbers of other pests such as crickets and cockroaches. However, since they can have a body length of up to 1.5inches, if you’re not expecting one in your home, it might come as a shock when you spot one. 

Don’t be too concerned though, despite their size, they pose little threat to humans. They are not aggressive and will not bite unless threatened or provoked. If they do bite, it can be painful but should not cause any more serious symptoms than mild swelling and irritation. If you feel worse symptoms, you may be having an allergic reaction and should seek medical help. 

Green Lynx Spider 

The Green Lynx Spider is a pretty but well camouflaged spider.
Photo by Vengolis on Wikicommons

At just under an inch long, the Green Lynx Spider is the largest of the Lynx Spiders but tiny compared to some other arachnids on our list. It’s the prettiest of them though, with its patterned leaf-green body and paler legs covered in black spots and spiny bristles. It would be distinctive if you could find it, but this spider is well camouflaged on the plants and cacti on which it lives, waiting for prey to ambush.

This colorful little spider has made it onto our list of venomous and unusual spiders because of the unique defense method it employs. The female Green Lynx Spiders lay large egg sacks, which they then protect fiercely, spitting venom at any predator that tries to get too close. This makes them one of the only actively aggressive spiders on our list (the jury’s still out on the Mexican Wandering Spider). 

They can spit their venom up to a foot away, and although contact with it is not dangerous for humans, we would still advise keeping your distance. The venom becomes a little more effective on the infrequent occasions that these spiders bite people. Although it is still not deadly, a bite may result in pain, irritation, and swelling around the area. 

there are around 66 species of tarantula in Mexico.
Photo by oleg-didenko on Unsplash

Are there venomous spiders in Mexico?

Yes, there are several species of venomous spiders in Mexico, but only three have venom which is dangerous to humans: The Black Widow, the Brown Recluse, and the Hobo Spider. Luckily, none of them are aggressive and tend to avoid contact with humans. 

What is the biggest spider in Mexico?

The newly discovered Mexican Wandering Spider is the biggest spider in Mexico, with legs up to 10cm long. 

Are tarantulas common in Mexico?

Yes, Mexico is the second most common place for tarantulas in the world, after Brazil. It is estimated that there are 66 species of tarantula in the country. 

What is the most dangerous spider in Mexico?

The Brown Recluse is the most dangerous spider in Mexico. Its venom is harmful to humans causing tissue death, large wounds, and deep scarring. It can be deadly if left untreated.