Gum Tree Shield Bug ( AKA Stink Bug )

Theseus modestus

It took 4 years for me to finally work out what my “Unknown Bug” is! Finding the Cotton Harlequin Bug was what lead me to it. I recognized that they look quite similar in structure and shape. This gave me some more terms to search for ( shield bug ) and I finally got a match! So it’s with belated pride I’d like to introduce to you, the “Gum Tree Shield Bug” otherwise known as a “Stink Bug”!

A nymph Gum Tree Shield Bug. The pattern on their back reminds me of an Aboriginal painting

The bugs that I found appear to be in the nymph stage. The nymphs spend most of their time under the bark while the adults roam about on the outside of the tree and are better camouflaged. The patterns on the nymphs is captivating, it looks like an Aboriginal painting come to life. Gum Tree Shield Bugs are found all over Australia in open forests or woodlands. They get their Stink Bug label from their ability to secrete a smelly corrosive substance as a defence against predators. Glad I avoided that.

A cluster of nymph Gum Tree Shield bugs. The nymphs are said to spend most of their time under the bark, I’m not sure how common it is to see them out like this.

Resources and references

• Queensland Museum
• Atlas of living Australia
• Brisbane Insects
• Save our Waterways Now

• Gum Tree Shield Bug
• Insect
• Shield Bug