Warning over 'destructive' bugs found in Aussie backyard

The colourful insects, while harmless to humans, can be problematic.

A swarm of eye-catching bugs huddled together on a backyard tree caught the attention of a resident who said she's "watched them grow" in numbers over the past few weeks.

But as beautiful as they may seem with their bright orange and blue hues, they're "extremely destructive" in large numbers, some have warned.

The insects appear to be harlequin bugs, part of the jewel bug family named for their bright metallic colouration. "The colour is associated with a warning," Australian Museum Entomologist Dr Chris Reid told Yahoo News Australia.

Swarm of orange harlequin bugs sitting on pod hanging from tree in Queensland backyard.
While beautiful to look at, harlequin bugs can be destructive in gardens. Source: Facebook

Colourful bugs wreak havoc on plants and flowers

The harlequin bugs on display in the woman's Queensland garden appear to be female which are mostly orange in colour, while males are usually mostly blue and red. The colourful insects are pretty common along the east coast of Australia, and while harmless to humans, can wreak havoc on gardens across the country.

"They have a proboscis (elongated sucking mouthpart) that they use to pierce plants and suck the life out of them and their flowers," an amateur entomologist shared on social media where the photos were posted last week.

The bugs are considered a pest to cotton plants, as they are known to introduce a fungus which rots the cotton ball. In gardens, they also cause flower buds to drop prematurely, according to the Australian Museum.

Warning over 'nasty smell' when handled

Harlequin bugs also have a serious stench when touched, just like any other species of stink bug. "When you handle them they produce a nasty smell ... They're a stink bug, it's a pest," Dr Reid said.

Left: Swarm of blue harlequin bugs sitting on leaf. Right: Group of colourful harlequin bugs sitting on fence.
Female harlequin bugs are mostly orange in colour, while males (pictured) are usually mostly blue and red. Source: Facebook

However, one person on Facebook suggested "removing by hand into a bucket of soapy water" and avoid using sprays which can "kill the good guys" needed for gardens to thrive. It's that or have them stay since birds are unlikely to pick them off due to their odour.

The homeowner revealed that, thankfully, "the tree itself appears really quite healthy, and not affected greatly by them", adding they're not seeing the destructive nature of them just yet.

"We have a native garden along the side of our property and embrace the biodiversity," she said.

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