The secrets of an exoskeletonNgā mea huna a te angawaho

Scuba tanks and ejector seats were invented by bugs long before humans thought of them. Excellent exoskeletons come in every shape, size, and colour imaginable. 

Harlequin beetle

Secret: fighting legs

The male harlequin beetle uses those long front legs to fight other males. The longer his legs, the better his chances of winning.

Sap on fallen fig trees is the best place to meet females and mate. It’s rare though, so that’s why winning a territorial fight is so important.

Secret: harlequin Airlines

Harlequin beetles provide transportation for the flightless pseudoscorpion. This arachnid isn’t a spider or a scorpion, but it does have eight legs and powerful pincers.

It uses those pincers to hang on to the harlequin beetle’s body as it flies to new territory. It even mates mid-air with its fellow passengers!

Harlequin beetle, 2016. Te Papa

Jewel beetles

Secret: shimmering armour

Exoskeletons make bugs strong, and sometimes beautiful too. Jewel beetles’ metallic colours are caused by light scattering on millions of tiny structures on the surface of their bodies.

Secret: burning desire

Some jewel beetle species lay their eggs in burnt forests. But first they have to find them. Luckily, they can sense pinewood smoke from 80 kilometres away – that’s about the length of Luxembourg!

Jewel beetles, Buprestidae, Worldwide, 2016. Te Papa

Dung beetles

Secret: mighty movers

Who’s the best at shifting poo? The dung beetle! It uses those strong legs to roll dung into balls and bury it in the ground – up to 250 times its own weight each night. That provides food and shelter for its grubs.

Dung beetles are popular with your farmers because they clean the land and fertilise soil.

Secret: night-time navigation

On a clear night, some dung beetles can navigate by the light of the Milky Way. As far as you humans know, they’re the only animals that can do that.

It helps them roll their dung balls in straight lines, which saves time. On cloudy nights they’re slower and can’t bury as much.

Dung beetle, 2016. Te Papa

Diving beetle

Secret: breathing underwater

Diving beetles trap air under their wing covers so they can breathe underwater. It’s like having built-in scuba tanks.

They use their hind legs to paddle, gliding along thanks to that streamlined shape.

Diving beetle, 2016. Te Papa

Japanese snail-eating beetle

Secret: skinny killers

If you want to eat snails, you need to get past their protective shells. And if you can’t break them, you have to get inside them.

The Japanese snail-eating beetle has a long, narrow head and thorax – all the better to reach its prey’s soft body.

Japanese snail-eating beetle, Carabus blaptoides, 2016. Te Papa

Giant Fijian longhorn beetle

Secret: powerful antennae

Keep your hands to yourself if you meet the giant Fijian longhorn beetle. It can trap a human finger with those powerful antennae, and its strong jaws can even draw blood!

Secret: warning hiss

An exoskeleton can protect with more than its toughness. The giant Fijian longhorn beetle hisses a warning when it feels threatened – by forcing air through a gap at the bottom of its wing covers.

Giant Fijian longhorn beetle, Xixuthrus heros, 2016. Te Papa

Tiger beetles

Secret: super sprinters

Those long legs help tiger beetles run after prey. Your fastest human can run at 6 body lengths a second, but some tiger beetles manage 125 beetle body lengths a second.

Things can get blurry at such high speed, so they feel for obstacles with their antennae, and even pause to get their bearings.

Tiger beetles, Carabidae, Worldwide, 2016. Te Papa

Giraffe weevil

Secret: his ’n’ hers snouts

You humans named this weevil after the giraffe. But that’s not a neck, it’s a snout! The male’s is longer than the female’s – he uses it to fight other males.

The female uses her snout to dig a nesting hole in wood, while her mate stands guard. Her antennae are further back so they don’t get damaged during digging.

Giraffe weevils, Lasiorhynchus barbicornis, Aotearoa New Zealand, 2016. Te Papa

Stag beetles

Secret: wrestling chops

Male stag beetles have large jaws that look like deer antlers. They can’t bite with much force, but they can wrestle. They’ll often toss another male out of the way to get to a female or food.

Stag beetles, Lucanidae, Worldwide, 2016. Te Papa

True weevil

Secret: sturdy snouts

True weevils come in all sorts of shapes, colours, and sizes. There are over 40,000 species!

Their mouths are right at the end of their sturdy snouts – ideal for digging into plant tissue to find food or make nests.

True weevils, Curculionidae, Worldwide, 2016. Te Papa

Wakefield’s click beetle

Secret: snappy joint

Imagine having a built-in ejector seat. Click beetles can catapult themselves up to 30 centimetres by quickly flexing their body. A great way to escape danger, and the accompanying click sound can startle a predator too.

If the beetle lands on its back, it simply clicks itself upright. Handy.

Wakefield’s click beetle, 2016. Te Papa