Small-headed hump-backed spider flies are a nightmare – if you are a spider!

Most people are familiar with spider hunting wasps, but have you ever heard of flies that kill spiders?

All known species of flies in the family Acroceridae – otherwise known as ‘spider flies’ – are internal parasites of spiders. In other words, their larvae feed inside spiders.

It’s how the larvae manage to get inside the spider that makes this story interesting. Let me know if you like the video!

6 legs = an insect?

It used to be thought that all animals with six legs were insects. It is now widely accepted that there are two groups of six-legged animals – the insects (class Insecta) and the entognathous hexapods (class Entognatha).

Entognathous means “inside jaw” – which refers to how their mouthparts are enclosed in folds of the head. Hexapod means “6 legs”.

The star of the show is Heterojapyx, a dipluran in the order Diplura. Don’t know what that is? Please watch the video to find out. It’s an amazing animal!

There is an old blog post on the same subject here.