Creepy crawlies can make people squeamish, even when they're small enough to get squashed easily by a shoe or a rolled-up magazine. But if the fear factor multiplies as the bug's size increases, then the giant bugs on our list will surely leave entomophobes and arachnophobes shaking in their boots.
It can be tricky to determine which bug should ultimately take the prize for size, as there are a lot of variables to consider, including weight, length and surface area, so our list includes the big winners in every category. Since comparing giant bugs is a bit like comparing apples to oranges, the final ranking isn't based on a sole factor but on the contender's overall impressiveness when it comes to being a giant of the bug world. Read on to see which creeping and crawling invertebrates made our list.
10: Hickory Horned Devil
This giant caterpillar has a fear-inducing name and frightful looks to back up its enormous size. The hickory horned devil can grow to lengths of up to 6 inches (15 centimeters), making it one of the world's biggest caterpillars. It boasts a collection of large, reddish-orange, black-tipped horns, which earned it the nickname of hickory horned devil (the "hickory" comes from the hickory trees that it usually calls home).
After burrowing into the ground to pupate, the mammoth caterpillar emerges as the regal moth (Citheronia regalis), itself a huge bug. Despite its intimidating appearance, the hickory horned devil is completely harmless. It doesn't even qualify as the sort of caterpillar that wreaks havoc on trees. This horned devil is no more terrifying than a common fuzzy caterpillar.
9: Giant Huntsman Spider
Where body size is concerned, the giant huntsman spider (Heteropoda maxima) doesn't have much to brag about with a body length of only 2 inches (nearly 5 centimeters). But this spider boasts the largest leg span of any arachnid, sometimes reaching more than 12 inches (30 centimeters). Its long legs look particularly impressive thanks to twisted joints, rather than vertical ones, that allow them to spread out laterally, much like crab legs.
Giant huntsman spiders may look terrifying, and they will bite humans. But the huntsman spider's "bark" (its terrifying size) is usually worse than its bite, which generally results in only minor pain and some local swelling.
8: Atlas Moth
The Atlas moth (Attacus atlas) gets its name from the patterns on its wings, which some say resemble maps. This moth certainly has the space for maplike designs on its delicate wings. It boasts the largest wing surface area of any bug, measuring in at an incredible 62 square inches (400 square centimeters). Although this moth doesn't have the largest recorded wingspan, it's not too shabby in that department either -- its wings can measure 10 to 12 inches (25 to 30 centimeters) from tip to tip.
Found across Southeast Asia, the Atlas moth produces strands of silk that are used to make a type of durable silk called fagara. Their cocoons also may end up as purses in Taiwan. As adults, these giant moths live for only two weeks and don't eat at all during that time.
7: Titan Beetle
The titan beetle (Titanus giganteus) certainly deserves its name -- titan being the root of the word "titanic." From the family Cerambycidae, the titan beetle can lay claim to being one of the planet's longest beetles, and definitely the longest found within the mighty kingdom of the Amazon rainforest. Some titan beetle specimens measure more than 6 inches (16 centimeters).
An adult comes equipped with a powerful set of jaws, strong enough to cut through a pencil or even through human flesh. But don't assume that the titan beetle uses its jaws to feed. In fact, as an adult, it doesn't eat anything it all, which may be one reason it never gets bulky enough to climb to the No. 1 spot on our list. It simply spends its short life flying around with one aim, namely to find a mate. Luckily, a bug this big would be hard to miss.
6: White Witch Moth
While the Atlas moth may take the cake for wing surface area, the white witch moth (Thysania agrippina) just edges it out for the prize of largest wingspan. From tip to tip, this member of the Noctuidae family has wings stretching up to 12 inches (31 centimeters). Found in South America, Central America, Mexico and sometimes even Texas, this moth's giant wingspan means that it often gets mistaken for other flying creatures, such as bats. The patterns on its wings give it amazing camouflage, particularly against tree bark. In terms of its butterfly cousins, the Queen Alexandra's birdwing butterfly rivals the white witch moth when it comes to wingspan.
5: Giant Weta
The giant weta of New Zealand offers a perfect example of the phenomenon known as island gigantism. Isolated from the rest of the world, these grasshopperlike insects have grown to tremendous proportions. In fact, the genus name Deinacrida, which many weta species fall under, means "demon grasshopper." That seems an appropriate description for a bug that can grow up to 6 inches (15 centimeters) in length. Though not as long as some other giant bugs, scientists sometimes point to the giant weta as a heavyweight. One Deinacrida heteracantha female laden with eggs weighed in at a whopping 2.5 ounces (71 grams).
In New Zealand's once mammal-free ecosystem, the giant weta originally filled the role that small rodents assume in other places. That role changed when Polynesian and European ships carried rats with them to the islands. Today, the weta has a collection of scary sounding nicknames, like "demon of the night" or "Taipo," which means "demon" in Maori. But these giant bugs pose no threat to humans and are content to stay secluded during the day and come out at night to munch on plants and forest floor debris.
4: Goliath Beetle
The name alone tips you off to the giant size of the Goliath beetle, found in Africa's forests and savannahs. In the Bible, Goliath was a Philistine giant who battled and was bested by a young boy named David. The massive Goliath beetle truly is a giant of the scarab family, reaching lengths of nearly 5 inches (13 centimeters) as an adult.
Five different Goliath beetle species live in Africa, the largest being Goliathus goliatus and Goliathus regius. Although not the longest of the giant scarab beetles, the Goliath beetle might take the prize when it comes to body mass and bulk. Goliath beetle larvae can tip the scale at more than 3.5 ounces (100 grams). Like its Philistine namesake, the Goliath beetle makes its fellow bugs look like pint-sized pipsqueaks.
3: Goliath Birdeater
Like the Goliath beetle, the Goliath birdeater (Theraphosa blondi) was named for the biblical giant because it's a spider of enormous proportions. Its leg span can reach up to 12 inches (30 centimeters), and it can weigh more than 6 ounces (170 grams).
Found in the rainforests of South America, this giant tarantula came by the name "birdeater" honestly. It received this distinction after a group of explorers caught one in the act of eating a hummingbird. These hairy spiders can eat birds, bats or even small rodents, but their more usual fare consists primarily of insects and occasionally frogs, small snakes and lizards.
Females can live up to 25 years, but males don't have the same longevity -- they usually die within a year of mating. In fact, the males barely make it out of mating alive, as they have to immobilize the females so they don't get eaten. Goliath birdeaters are less dangerous to humans than they are to each other. They do have venomous fangs and can pierce through skin, but the venom isn't much more potent than a wasp's sting. The Goliath birdeater can, however, release barbed hairs that can cause irritation, particularly if they get into the eyes, mouth or lungs.
2: Hercules Beetle
With mega names like Goliath sprinkled throughout our list, it's not surprising that the second-to-last spot should be filled by a bug known as the Hercules beetle (Dynastes hercules), named for the hero of Greek mythology. This enormous scarab, found in Central and South America and the Lesser Antilles, can reach the enormous length of almost 7 inches (17 centimeters). Much of its impressive length comes from the two horns at the front of the body. The cephalic horn curves upward from the lower part of the head, while the thoracic horn curves downward from the top. These horns give the Hercules beetle a place among a group known as the rhinoceros beetles. They also factor into battles between males, when the males use their horns to lift and then fling their opponents. The horns can cut rivals literally in half.
The Hercules beetle has tremendous strength, much like the mythical Hercules, and can reputedly carry hundreds of times its own body weight. Native South Americans sometimes eat Hercules beetles in the hopes of magically receiving some of the beetle's size and strength. Not only does the Hercules beetle boast immense size, it also has a voracious appetite. Scientists have observed Hercules beetles in captivity consuming almost a whole avocado in a single day. The combination of incredible length, strength and a huge appetite to add bulk make the Hercules beetle the king of giant bugs.
The largest known insect on Earth, Mothra, is a giant of the order lepidoptera, with a wingspan of up to 820 feet, or 800 times that of the next-largest moth, the White Witch.
Weighing in at up to 25,000 tons, Mothra can fly at speeds reaching Mach 3. Her giant wings can create gale-force winds - a useful skill for an insect who must battle terrible monsters like Godzilla. She reproduces parthenogenetically, dying just as her larval offspring hatches, Phoenix-like, from her giant egg.
Though equipped with an arsenal of deadly defenses, including the ability to shoot rays from her antennae, encase her enemies in streams of silken thread, and emit clouds of poisonous yellow dust, Mothra is a benevolent monster. She uses her powers to create balance in the cosmos, defend the earth against enemies, and battle the forces that threaten to destroy the planet's environment.
*Editor's Note: To date, Mothra has only been sighted in film; the majority of documented sightings have occurred in Japan.