World's Largest Insects: Atlas Moth; Titan Beetle; Giant Weta; Giant Centipede; Giant Walking Stick

When considering what the world's largest insects are, it's important to be specific about what that really means. There are many factors to compare such as the weight, surface area, wingspan, and pure length of the organism. These five insects are all record holders for being the largest insects in the world, and the ways they live are as impressive as their colossal sizes.

Atlas moth (Attacus atlas) - Largest Surface Area

The Atlas moth of southeast Asia is a sight to behold, with a total wingspan of 10-12 inches (that's an entire foot). Although some other moth species rival this measurement, the Atlas moth is considered the insect with the largest surface area - 400 square cm or 65 square inches. If placed on a child's back, the moth will take up a great deal of space.

As a consequence of their size, these moths don't make the best fliers, so a female wouldn't stray far from the chrysalis from which it emerged. Even the caterpillars of the Atlas moth are big, growing up to 4.5 inches. They have fleshy spines on their backs, making them less appealing for an easy meal.

Click here to see an image of the Atlas moth. Take note why it is the largest despite not having the greatest average wingspan.

Giant Walking Stick (Phobaeticus chani) - Longest Length

The giant walking stick refers to several species of extraordinarily long "stick insects". Of these groups, the Phobaeticus chani stands out as the longest known insect in the world. One specimen from the Natural History Museum in London is 22.3 inches long (with front legs extended) - more than a foot and a half. Imagine seeing something like that walking in front of you. That's not a stick, it's a walking stick.

The body size without the front legs extended is 14.1 inches, which is still impressive. The species is typically difficult to find and not much is known about its biology. Even its discovery has been recent, as it was named one of the top 10 new species of 2008 by The International Institute for Species Exploration. Who knew that the longest insect in the world would also be one of the toughest to find?

Goliath Beetles (Goliathus) and Titan Beetles (Titanus giganteus)

Now let's get to bulk, weight, and true "size." The goliath beetles of Africa are strikingly big. They are protected by an armored exoskeleton and are among the heaviest insects on Earth. Hearing it fly (yes, it can fly) is like hearing a kid's toy helicopter buzzing through the air. The titanus beetle is also a juggernaut; the largest beetle of the Amazonian rainforest. Full grown adults can grow up to 6.5 inches long, similar to the size of the Goliath beetle. Both species are considered the largest beetles and are known for their extreme weight. When held they can easily cover an entire human palm.

Beetles feed on rotting fruits and animal feces on the ground. Were it not for these creatures, the rainforests would be much dirtier. The titan beetle is in fact known to have mandibles strong enough to snap pencils. Click here to watch a video of the titan beetle from David Attenborough's series, Life in the Undergrowth.

Giant Weta (Deinacrida heteracantha)

The first thing that comes to mind when seeing a giant weta is that it looks like a giant grasshopper. They are endemic to New Zealand and are a prominent example of island gigantism, a phenomenon in which geographical isolation (like on an island) causes incredible increases in size compared to mainland relatives.

The giant weta can grow up to 4 inches long. While not the longest, this species belongs on the largest insect list because it is one of the heaviest known insects on the planet. One specimen was measured to weigh 71 grams (2.5 ounces). Unlike grasshoppers, the giant weta is unable to jump because it's simply too bulky. Click here to see images and learn more about this insect.

Amazonian Giant Centipede (Scolopendra gigantea)

Of all giant arthropods, the Amazonian giant centipede is probably the most terrifying. It primarily hails from the western and northern regions of South America and feeds on a variety of large animals - frogs, birds, bats, and even tarantulas. They are able to walk fast and use curved claws around its head (called forcipules) that can inject highly potent venom into prey. This venom is fatal to the animals it feeds on but to humans it is unlikely to cause death. It does, however, cause intense pain, chills, fever, and other symptoms.

So how large do these centipedes grow? 10-12 inches. The bodies consist of up to 23 segments and its striking colors make it appear even more dangerous. Watch this video here of it facing a tarantula in combat and emerging victorious. Here is a picture depicting its frightening appearance. Despite all of its fearsome assets, the arthropod is popularly kept by pet enthusiasts with proper regard to safety.

References

Watson, A. & Whalley, P.E.S. (1983). The Dictionary of Butterflies and Moths in colour. Peerage Books, London, England.

Robinson, G.S., Ackery, P.R., Kitching, I.J., Beccaloni, G.W. & Hernández, L.M. (2001). Hostplants of the moth and butterfly caterpillars of the Oriental Region. Southdene Sdn. Bhd., Kuala Lumpur & The Natural History Museum, London. 744 pp. ISBN 983-40053-3-4

R. M. Shelley & S. B. Kiser (2000). "Neotype designation and a diagnostic account for the centipede, Scolopendra gigantea L. 1758, with an account of S. galapagoensis Bollman 1889 (Chilopoda Scolopendromorpha Scolopendridae)". Tropical Zoology 13 (1): 159-170. ISSN: 0394-6975.