Monthly Archives: November 2015

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


Cotton Harlequin Bug

Tectocoris diophthalmus

A few weeks ago we visited friends in their new highrise apartment in town. It was an awesome place, typical modern apartments, all fitted out with parking and facilities including a great indoor pool that we had a lot of fun in with the kids. They were on the 30th floor ( I think ) very high up anyway. It was the last place I would have expected to see some interesting wildlife but while Jess and I were out on the balcony scaring ourselves with the hight ( ok, mostly me being scared  ) I spotted a strikingly coloured bug crawling on the tiles. I gave it to Jess, we both marveled at it and took some photos. I’ve found it hard to identify bugs in the past and didn’t expect to be able to work out what this one is, but by luck someone had found exactly the same creature and sent in a photo to the North Shore Times where it was identified by the Australian Museum as a “Cotton Harlequin Bug”!

The Cotton Harlequin bug is a true bug in the jewel bug family. They are found Northern and eastern Australia; New Guinea, some Pacific islands and are common in the summer months.  They suck sap from hibiscus plants and related species and are also considered a minor pest for cultivated cotton.

The individual we found is a male, their colouring is reported to be quite variable but it seems common for them to be red with striking metallic blue markings as we found. The females are orange with smaller metallic blue markings. I think another case of the males being prettier than the females!

Male Cotton Harlequin Bug found on the 30th floor
The same picture close up. Looks like he had his wing stuck, he was a long way up with no food in sight, I hope he worked it out.

Resources and References

Australian Museum


Queensland Museum

Brisbane Insects

Atlas of living Australia