History of The Terms
When talking about Old World and New World, the origins of these terms came about in the late 15th century, right around the same time Christopher Columbus became known as a renowned European explorer. When he returned back to Spain after “discovering” America, he was referred to as the discoverer of the New World.
A couple of years later, published works began to come out that reinforced that New World title, and it clearly stuck. The Europeans lived on that term and then began implementing the Old World comparison as they began navigating through Africa and Asia. In a sense, the terms were a quick way for them to distinguish between the two parts.
Now, since Australia was only recognized in the early 17th century, it really does not fall under either term. But because it has similar tarantulas by nature as found in Africa, many hobbyists classify them as Old World as well.
TL;DR: What is the difference between old and new world tarantulas?
It is the origin of the species which will determine whether it is classified as Old World or New World.
Old World tarantulas are from the eastern hemisphere: Africa, Asia, Australia (Oceania) and Europe whereas New World tarantulas are from the western hemisphere: North and South America.
However due to a divergence in evolution, caused by the different environmental factors such as temperature, habitat, availability of food, there are certain traits which are common between each of the two classes.
Old World Tarantulas
Old world tarantulas are not for the faint hearted (literally) as they are typically lightening fast, highly defensive and can be very quick to bite.
Many hobbyists have described their old world tarantulas as “teleporting” due to their blistering speed.
Although a tarantula’s first defense is normally to flee, if cornered or exposed, old world species will not hesitate to strike.
Considered to be the more aggressive species, it is not uncommon for an old world species to go into a threat posture (raising its front legs and showing its fangs). Simply walking past their enclosure or refilling their water dish can cause them to react.
Not only is their readiness to bite a cause for concern, old world species also typically have higher venom potency than new world species. While not all bites will involve venom being injected (known as a “dry bites”), their bites can be excruciatingly painful and can lead to the requirement of medical assistance.
If you are unlucky enough to be subjected to their venom, depending on where you were bitten, typical symptoms can include: significant pain, severe muscle cramping (sometimes lasting for days, weeks or even months), localised swelling, difficulty in breathing and occasionally fever and nausea.
New World Tarantulas
If you are new to the hobby, or thinking about getting into the hobby, new world species are what are typically recommended. See Tarantula Keeping for Beginners.
While there are exceptions, species such as Brachypelma Hamorii (Mexican Red Knee) and Grammostola Rosea (Chilean Rose Hair) are typically regarded as beginner friendly.
New world tarantulas, particularly the terrestrial species, are typically much slower moving than their old world counterparts.
The Major Differences
There are several differences between Old World and New World tarantulas, with behavior, defense, and the potency of their venom they have being the key differentiators.
For instance, nearly all New World species have an exclusive defense that Old World species do not have, and that is their special hairs called Urticating Setae. This covers the upper back area of the abdomen or the opisthosoma and are perfect little barbed hairs that can puncture the skin or eyes of their attackers.
Unlike old world tarantulas whose main defence is their potent venom and bad attitude, most new world species’ (similar to some caterpillar) primary method of defence if their urticating hairs (setae).
Urticating hairs are barbed hairs that they will kick off their abdomen using their back legs when feeling threatened. This creates a cloud of microscopic hairs which, being highly irritating (especially if they come in contact with eyes or get into the mucous membrane of the respiratory system), is an effective deterrent to wouldbe predators.
There are six known different types of urticating hairs varying in different shapes and sizes. Depending on the species these have evolved over time to be effective against the common predators of that species.
Urticating Hairs Effect on Humans
Due to these different types of hairs the intensity of the irritation to humans varies from species to species and also from person to person. The species which is often noted as being the most irritable to humans, which also happens to be the world’s largest tarantula, is the Theraphosa Blondi (Goliath Bird Eater).
If you happen to come in contact with Urticating hairs, you may feel slight itchiness or form a severe skin rash. In some cases, it can cause very painful irritation, especially if you get it near your eyes. Now, if your breath in some hairs, it can cause your throat to close up, making you have a hard time breathing.
These hairs are not to be taken lightly. There are reports of people blistering and bleeding after coming into contact with them.
Overall, the symptoms vary from person to person, but regardless it would be wise to get medically checked out just in case, even if you got the mild side effects.
Popular species that have this characteristic include:
- Brachypelma smithi – Mexican Redknee;
- Grammostola rosea – Chilean Rose;
- Acanthoscurria geniculate – Giant Whitknee;
- Avicularia – Pinktoe Tarantula.
Though the Psalmopoeus and Tapinauchenius are New World tarantulas, unlike the above they do not have these hairs. In addition, the Ephebopus to have these hairs, but on their pedipalps instead.
Overall, Urticating hairs range sizes from 0.06mm to 1.5mm and are barely visible with your naked eye. They are also used in two different ways, one being the tarantula facing away from the threat, making fast rubbing movements to launch the Urticating hairs into the air towards the danger. The other way, demonstrated by Avicularia, Pachistopelma, and Iridopelma, is waiting for the threat to come in direct contact with the hairs.
Fun Fact: Though this is a clear distinction between the two types, tarantulas are not born with these hairs. They form over time after each consecutive molt during the tarantula’s growth cycle. They start with a patch that just continues to grow after each molt session.
While many of the new world species rely on their urticating hairs as their primary defence. While not normally as potent as the old world species, if provoked, they can also bite.
Second Major Difference – Potency of the Venom
The second highly notable difference between New World and Old World species is the venom.
Can a tarantula bite kill you?
In summary, Tarantula venom is neurotoxic and serious effects for humans are uncommon. In fact, though the bites can be excruciatingly painful, there are no known fatalities caused by a tarantula bite reported. However, you could get an allergic reaction or secondary infection, in which medical assistance is necessary.
Getting back to the fundamentals, if you are bitten from a New World tarantula, it will probably feel similar to a bee sting. You will feel the initial pain from the fangs puncturing your skin and might feel sore for a while afterwards.
Though bites are common in both species, you are much more likely to get bitten by an Old World tarantula, as they are known to be more defensive. Keep in mind that, yes, there are venom differences, studies on Old World tarantula venom are not well developed (yet).
However, it is evident that they have more potent venom than any of the New World species, sometimes landing people into hospitalization. The tarantulas that are said to have the most potent venom are:
Caring For New World Tarantulas
Owning a tarantula is growing in popularity today. They are noiseless, beautiful creatures that require little maintenance to keep sustained. Though as easy as they are to care for, you still have to follow a strict guideline in order to keep them happy. One wrong move could result in an injury to your spider, and that is the last thing you want.
- Feeding: First and foremost, tarantulas in captivity are very easy to feed. They can live off of common foods, primarily insects, and most only need one or two crickets a week to be well fed. Larger ones will need more, probably up to 6 crickets a week. Note that crickets are not the only thing you can feed them. Roaches, waxworms, and fruits are all great options as well. Just make sure to take out any food during a molt, as this process makes your tarantula vulnerable. Meaning, those live crickets can actually attack your spider during this state.
- Handling: Because New World species are docile, you are not likely to pose a risk to them if you choose to handle them. Just make sure that with each handle, you are in a safe place where you will not drop them, give them the opportunity to escape, or any other accidents. If your spider shows distress from being handled, such as flicking Urticating hairs at you, leave them alone and immediately wash off your skin, eyes, and clothes.
- Housing: For the average adult tarantula, a 10-gallon terrarium is plenty big enough for them. They do not need much space, but they do need accessories and enough room to hide to feel calm. The space should have about 60-70% humidity, a total temperature of about 75-80 degrees, and there should always be water available to them.
Caring For Old World Tarantulas
Though the above tarantula caring tips above overlap a great deal with Old World tarantulasthese species require a bit more cautionary measures to be taken into consideration. Common Old World species include:
- Chilobrachys fimbriatus – Indian Violet
- Idiothele Mira – Blue Foot Baboon
- Pterinochilus murinus – Orange Baboon Tarantula (aka Orange Bitey Thing)
- Haplopelma lividum – Cobalt Blue
- Haplopelma schmidti – Chinese Earth Tiger
- Hysterocrates gigas – Cameroon Baboon
- Ceratogyrus darlingi – Horned Baboon
For these tarantulas, the critical thing you remember is that their behavior is very different than New World species. They are more defensive, and since they do not have Urticating hairs, they rely on their venom to protect them. They are faster, easier to provoke, and are territorial. For most owners, they opt out of handling these spiders altogether and just admire from afar.
The Tarantula Life Cycle
Something that both Old World and New World species have in common is their life cycle. Yes, it can range significantly based on the particular types of spiders, which is why you should look into your desired future pet before investing. Regardless, in general, you can expect the following:
- The Molting Process: Spiders on both sides shed their exoskeleton skin to grow. They do this several times a year (more so when they are younger) because it is part of the maturation process. When they are full-grown, you can expect them to molt once a year, or even less. Again, the main difference here is that New World tarantulas will grow Urticating hairs with each molt, and the Old World ones will not. Furthermore, during this cycle, your tarantula will be lethargic, vulnerable, will stop eating until the process is over.
- Reaching Full Growth: For most species, tarantulas can live for many years. It may take them about two to five years to reach adulthood, but some can take longer, up to ten years to get to that point of full maturity. Based on the species you have, make sure that you know how big your tarantula will get, so you ensure that you have a tank big enough to accommodate them.
- Life Duration: For females, they have been known to live up to 30 to 40 years in the right conditions. Not all live that long, though. For example, the Grammostola Rosea spiders can live for up to 20 years in captivity with eating just once or twice a week. Males tend to live a lot less, ranging around 10 to 12 years. This is one of the main reasons why many owners seek out female tarantulas, as they can live twice as long.
Fun Fact: Male tarantulas rarely molt again once they reach adulthood. If they try, there is a probability they can die because they become stuck due to their sexual organs getting in the way. On the other hand, females will still molt after maturity.
As you can see, though they are all spiders, there are some apparent differences between the Old World and the New World tarantulas. In a nutshell, New World species are often called docile and are the kind recommended for beginners. They are slower and have a less impactful bite. Just make sure to take care if handling them to reduce your exposure to those Urticating hairs.
Alternatively, you can still own Old World species as well, but these ones are usually recommended for the experienced keepers. Even though these tarantulas may be less hairy, they feature much more defensive behavior, faster, and may require medical help if you get bitten.
In the end, whatever you decide to do, make sure you research the kind of tarantula you desire to have so you know how to care for it properly. In addition, always remember that every tarantula species, both New World and Old World are incredible spiders that play an essential role in the world, and they deserve respect.