Name: Darwin's Beetles Spar Off
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Beetles make up the largest group of insects on Earth. Why do so few of them have massive pincers?

Beetles make up the largest group of insects on Earth. Why do so few have massive pincers?

Darwin's Beetles Spar Off

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<div class="rich-text">Beetles make up the largest group of insects on Earth. Why do so few of them have massive pincers?
</div>

<div class="rich-text">Beetles make up the largest group of insects on Earth. Why do so few have massive pincers?</div>

Nature

<div class="rich-text"><h3>
 Darwin's Beetles Spar Off
</h3>

 Published May 23, 2018



 Onscreen:
 
 There are hundreds of thousands of different species of beetles.
Why do just a few have giant weapons?



 Doug Emlen:
 
 So, there’s an animal with an incredible weapon.



 Narrator:
 
 The male Darwin’s beetle, from Chile, has an enormous set of pincers for its size. These specially adapted jaws can make up half their body length.



 Emlen:
 
 That is one of the biggest weapons of any living animal, ever. They’ve got mouthparts, or mandibles, that have been elongated so that they have these curved arcing pincers. And the pincers in these males can be even longer than the rest of the body of the animal.


 So, the males are fighting battles with rival males, so these are two males sparring and facing off against each other, trying to fling each other from the tree. For the loser, it’s a long way down.



 Narrator:
 
 But what’s the point of this epic battle?



 Emlen:
 
 Beetles like this fight over wounds, sort of, marks or nicks on the sides of a tree, where sap will ooze out and drip down the side. Females feed on that sap.



 Narrator:
 
 By guarding the sap, a male beetle gains access to females.



 Emlen:
 
 So, that means that if you’re a male and you can hold onto that real estate, you have opportunities to mate with the females when they come in to feed.



 Onscreen:
 
 Meet more creatures with giant horns and tusks.

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