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Living Lightly column

What’s that Jewel Flying Around in Your Garden?

By Jonathon Howard, Albury

Sometimes the small things that surround us can be fascinating. Cuckoo wasps are those remarkable iridescent blue-green jewels you see hovering slowly around your house looking for wasp nests.  Although about the size of a fly, these wasps live a bold and vibrant lifestyle.

You see, cuckoo wasps are ‘parastoids’. That is, they are more than just parasites. They do not just take something from their host and then leave, cuckoo wasps actually kill their host and steal their food.

Like the bird cuckoo, cuckoo wasps infiltrate the nests of other wasps- in our region mud wasps – and lay an egg. The egg hatches and the larva will eat the mud wasp larvae and all the spiders that have been paralysed in the mud wasp nest. That is right; they are also cleptoparasites and steal their host’s food.

These bold little insect regularly infiltrate the nests of much larger wasps. This might seem dangerous, but the adult Cuckoo Wasp’s body is well armoured and has a concave body so it can curl up into a tight armour-plated ball. This is a defence behaviour against the attack by angry mother wasp defending a mud nest against invasion.

Since the cuckoo wasp depends on trickery to fool their hosts, you might expect them to be camouflaged, but they are not. The vibrant colour comes from light refracting through open spaces between six layers of cuticle in their tough exoskeletons. If you look closely you will see the body is covered in tiny, dense pits, which gives them their glittery appearance.

If you do spot one of these flying jewels in your backyard, try to get a closer look. Do not worry about the prospect of a sting.  Research has found the sting apparatus is reduced and supposedly non-functional. The local ones certainly do not seem to have any desire to sting us or attack us.

Enjoy these hovering jewels in the garden, do not spray them with pesticide. All living things have a place in the world even the most bizarre. Instead you might consider that while these little iridescent blue-green jewels might seem busy trying to duck their parental responsibilities, it’s not exactly easy living.