Australia Weather News

Swarms of red bugs have appeared across South Australia in recent weeks as favourable weather conditions and a hunt for food have allowed populations to flourish.

Confused residents in the Riverland flocked to social media to share their surprise at seeing the bugs in such large numbers and their frustration at the mess left behind on car windscreens when travelling along the highway.

"There's thousands of them here, I've never seen these type before," Lorraine wrote on ABC Riverland's Facebook page.

"Could not see through my window by the time I got home," Dianne said.

Identifying the insect species has proven difficult for bug experts and entomologists, who say more than 10 bugs share similar behaviours and characteristics.

SA Museum entomology collection manager Ben Parslow said the "large numbers seen in the Riverland and across Adelaide" were most likely soapberry bugs.

"It's a species calledLeptocoris mitellatus, and they're essentially a common Australian species of soapberry bug that's quite broadly distributed," Dr Parslow said.

"What they do is actually feed on seeds of plants in the soapberry family, hence that common name."

Department of Primary Industries and Regions principal entomologist Peter Crisp said the soapberry bug was a real possibility, but it had been difficult to determine through photos alone.

"I would tell you, it is so dry, everything is heading into the city where there may still be a little bit of moisture," Dr Crisp said.

'Harmless to people'

Hives of activity around homes, cars and workplaces have also left people wondering whether the red bugs carry any disease or pose a threat to health.

Dr Crisp said all the likely varieties were "harmless to people".

"They're sucking insects, so they may actually suck on a tomato or an apple and cause a little bit of dimpling, so there is potentially a little bit of low-level economic damage," he said.

"I think they're just more noticeable in the towns and orchards because there's just nothing anywhere else for them."

Dr Parslow said there were "no kind of records" of the soapberry bug "being harmful for humans".

"If you do squash them, they can often produce a little smell and odour as a general defensive mechanism, but in general, they are not going to be poisonous to humans," he said.

Dr Parslow said they would likely begin "to reduce in population size" as autumn began.

"We're going to be right on the cusp of their numbers starting to decrease, [but] I think we'll still have a little bit of time with them with the hot weather," he said.