万圣节来临 我们来谈谈巧克力蠓虫

This is Scientific American - 60-Second Science. I'm Christopher Intagliata. As you unwrap a Halloween candy or two,

it's worth paying your respects to the real reason for many of the treats: a tiny fly whose trick is to make chocolate possible. They're all in the family Ceratopogonidae, which is the biting midges family.

But not all of the adults bite. How we usually do it is we call them 'Cerats. ' Erica McAlister is a at the Natural History Museum of London, and author of The Secret Life of Flies.

The cerats-related to no-see-ums-do a job that's very hard to get done by hand: they crawl through long, twisty cacao flowers, pollinating the stubborn cacao tree.

Which produces the beans used to make chocolate. They are really, really difficult to pollinate. So you do need these little things to do it.

And to McAlister, at least, the tiny midges are a beautiful sight to behold. They look like a very tiny mosquito, but they are basically absolutely covered in hair,

they're very beautiful, very hirsute little organisms. And the males have got the most-they look like feather duster antennae.

Because he's got to not only smell for the female, he's listening. And his ears are on the antennae. They're not very robust, these things, they're tiny, as the name implies.

They've got nice external genitalia for the boys. . . I don't know what else you want me to say. Well, here's the bad news: The chocolate midges are in danger,

as farmers clear out shade-grown rainforest plots, in favor of sunnier monocultures of cacao. That threatens the tiny flies, which need the damp rotting leaf litter of the forest floor to thrive.