Is a six legged spider a myth or a fact? If a fact, does it mean not all arachnids have eight legs? And if a myth, what are these regularly spotted six legged spider-like insects?
Spiders are scientifically classified as arachnids. These are a class of animals that include ticks, mites, and scorpions.
Compared to the other arachnids, spiders form the largest group and are the most diverse when it comes to species population. There over 45,000 known species of spiders. And because of their diversity, they occupy a wide range of habitats.
There are few stand-out features of spiders that include 4 pairs of legs, and a body that is made up of two main parts – the cephalothorax (which is a combination of the head and thorax) and the abdomen.
Spiders differ greatly in size. The largest one is the tarantula whose leg span can grow to almost a foot long. On the other hand, the smallest known spider is about 1mm long.
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Do All Spiders Have 8 Legs, or is there a Six Legged Spider?
As mentioned earlier, spiders are arachnids and all arachnids have eight legs. This means that they are structurally different from insects, which have six legs. That is why spiders move or walk differently from insects.
Usually, a spider will have two pairs of legs on the cephalothorax and two others on the abdomen. But this may differ from species to species.
So is a six legged spider real? The simple answer is no. All spiders come with eight legs. However, that is not say to say that there are no spiders with six legs. It is common to come across spiders that are missing a leg or two, or even more. But that is not how the spider was originally.
Spiders frequently lose their legs in accidents. This happens a lot especially after rough encounters with predators such as ants or birds.
Other spiders lose their legs in territorial fights or after mating with a cannibalistic female. So a spider with fewer than eight legs is a surprisingly common occurrence.
Fortunately, scientists have established that spiders have more legs than they need. So losing a leg does not affect them. They can still perform normal activities such as building webs and hunting prey.
A six legged spider is perfectly capable of catching prey with ease just like a normal eight-legged spider.
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Spiders are not Insects
So for those wondering; is a six legged spider an insect or a spider? You need to know that spiders are not insects. They are arachnids that have eight legs.
If you come across a spider that has six legs, then definitely it has lost the other limbs. Otherwise, any other six legged spider-like creature is either an insect or a bug.
Apart from the number of legs, there are many other features that distinguish spiders from insects. For instance, spiders don’t have wings while most insects do.
But, not all insects have wings. This explains why we have many six legged spider-like insects without wings that could easily pass for spiders.
Another distinguishing feature is that insects have antennae while spiders don’t. However, please note that some spider species have converted their front limbs to perform a sensory function. So the front pair of legs may be mistaken for antennae creating a false impression that they are six legged spiders.
In addition, spiders are further distinguished by the two distinct body parts while insects have three – a head, thorax, and abdomen.
An Exception: Ant Mimicking Spiders
It is also worth noting that spiders have about six or eight eyes, while insects have only two. Despite that fact, insects have superior vision compared to spiders, which have to rely on their sense of touch especially when hunting.
By now, it should be clear that the idea of a six legged spider is a misconception or a myth. But are there spiders that appear as if they are six legged? Yes, there are.
Ant mimic spiders such as the Myrmarachne are a perfect example. There are over 300 species of spiders that have been known to mimic the appearance of ants for various reasons.
For some, it is a defense mechanism to avoid predation. Ants are aggressive insects and because of that, many predators typically avoid them. On other hand, smaller spiders especially the non-poisonous ones are considered easy prey by many predators.
So to avoid predation, these spiders try to mimic the appearance of ants. For instance, they walk around waving their front pair of legs near their heads to simulate antennae.
This makes them look more like ants than spiders. That is why some people confuse them for six legged spiders.
Ant mimicking spiders also have a “false waist” on the cephalothorax to mimic the three-segment structure of ants. They could also be covered with reflective hairs to mimic the shiny outer appearance of ants.
Some ant-mimic spiders also prey on ants. So they mimic them to lure them so they can kill and eat them.
Six Legged Insects that Look Like Spider
It is good to acknowledge that the claims of six legged spiders are not unfounded. Part of the reason for this is the fact they are many insects that look like spiders. As a result, people mistakenly refer to them as six legged spiders whereas they are not.
Below are a few of them:
1. Snow Fly
A snow fly is a six legged spider-like insect that is about a quarter-inch in size. They are commonly found on the ground or plants burrowed under snow.
Many people actually refer to it as a snow spider. This could be because snow flies are wingless and have furry bodies like spiders.
However, a snow fly is not a spider at all. It is a wingless insect that is closely related to crane flies. They are relatively unknown, even by scientists, compared to other species of insects which explains the misconception.
They spend most of their time hidden under snow. They seldom eat as adults and, therefore, they rarely come out which may explain why they don’t need wings. They only come out to mate or look for a place to lay eggs. And usually, they will wait for when the temperatures are freezing cold.
When above the ground, they move pretty fast for insects of their size. They can cover about 4 feet in a minute. Only spiders can walk this fast because of their many limbs. This could be another reason why snow flies are mistaken for spiders.
2. Dragonfly Nymph
The dragonfly nymph is another six legged insect that looks like a spider. To begin with, the head and thorax are not as distinct as that of other insects. Also, because the dragonfly nymph is still in its developmental stages, it has yet to develop wings. So it is wingless just like a spider.
Dragonfly nymphs are voracious carnivores like spiders. You can distinguish them by their extendable mouthparts which assist in catching prey. The lower jaw resembles a scoop.
They are commonly found in ponds margins and can move pretty fast on water like a garden orb-weaving spider.
Because they are fully aquatic, dragonfly nymphs use gills to breathe. However, the gills are not visible because they are located inside the abdomen. That is why they could easily pass for water spiders. They are also able to move fast by forcefully ejecting water from the abdomen.
At the nymph stage, it is hard to tell what a dragonfly nymph will become. You have to wait until it matures to see what it will turn to. When it is old enough, it cracks open its back and the dragonfly comes out.
3. Spring Tail
Although they have six legs like insects, springtails are actually not insects. They are closely related to crustaceans but are more like six legged spider-looking bugs.
They are also wingless and can’t fly – just like spiders. Because of this, they move about by jumping or walking. It’s not a wonder then that some people erroneously think that they are tiny spiders.
You can find them in large numbers like black pepper on soil or snow. They love feeding on decaying vegetation and other organic matter which is why they can be found gathered around tree trunks or in the soil.
When soils become dry, they move out in search of more moist conditions. This leads them to seek habitats inside homes, greenhouses, garages, and basements.
You can also see them in damp carpets or under kitchen sinks. These are the same areas that spiders inhabit.
However, although they can jump like fleas or jumping spiders, they do not jump using their legs. They have a spring-like mechanism that is found underneath the body. They use this to catapult themselves into the air. That is why they are called springtail.
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4. Assassin Bug
This is a wingless six legged bug that looks like a spider. An assassin bug is relatively large compared to spiders. It can grow to about 37 mm or 1.5 inches in length.
One major distinguishing feature of assassin bugs is that they have thickened forewings that have membranous tips. These help in handling prey.
It also has an extended segmented beak that is not there in spiders. The beak can be folded to fit underneath its body. Assassin bugs use this curved beak as a siphon.
They mostly feed on insects just like spiders. After it catches prey, the assassin bug sticks the beak into the insect and sucks out its liquids.
It leaves an empty skeleton just like spiders do. This is another reason why some people think it could be a spider.
In their larval form, they are wingless and smaller and so resemble six legged spiders.
Most people don’t mind them because they feed on pests insects like flies and caterpillars. However, it is good to note that their bites can harm you.
5. Wheel Bug
The wheel bug is also a six legged spider-looking bug. It is a species of the assassin bug. Wheel bugs usually have a cog-shaped dome on their back that looks like the wheel of a ship hence the name.
Another thing that stands out in wheel bugs is the hairy legs that resemble those of a spider. They help to prevent prey from escaping.
Also, the females are larger than the male which is also common in spiders. Adult wheel bugs are dusty gray so it is easy to mistake them for spiders.
However, their body structure is slightly different from that of spiders. They have a small narrow head, antennae, and two large black eyes.
It has similar feeding habits to spiders. It uses a dark long fang to penetrate prey and then injects a mix of toxic enzymes that kill and even start digesting the prey from the inside.
It is a fairly common bug that is widely distributed. And although it is a beneficial bug because it preys on pest insects, it has a very sharp bite that is worse than a bee sting. You need to be very careful when around it.