The ever-evolving katydid

The katydid, an insect that for millions of years has remained on the right side of natural selection, did so by continually adapting its complex camouflaging strategies

- Mike Burgess

A few years ago, I discovered my first leaf katydid (Eurycorypha sp.) among my veranda pot plants. I was amazed by its ability to perfectly mimic a green leaf in shape, form, pattern and even texture. Only a few days later, a beautifully decorated Acacia katydid (Terpnistria zebrata) came flying in from nearby sweet thorn trees in which they specialise to live in plain sight of predators.

I soon discovered that these two insects were members of a global family of thousands of katydid species found on all continents except Antarctica. Some are as small as a pinkie nail while others are as large as a human hand. All are known for their exceptional camouflaging abilities and by the common name, katydid, derived from North American species that rub their wings together to produce the unmistakeable sound: ka-ty-did.

EVOLUTIONARY CAMOUFLAGE

Because most species of katydids are nocturnal, they are vulnerable to predation during the day and have, therefore, evolved camouflaging strategies to counter this vulnerability. This survival strategy has had obvious evolutionary rewards as it has allowed them to avoid wholesale predation and ensure genetic continuation.