A Golden Christmas Beetle enjoying some eucalyptus leaf.
A Golden Christmas Beetle enjoying some eucalyptus leaf. Noah Kirkland

This spot is the 'perfect storm' for Christmas beetle swarm

CHRISTMAS trees are starting to appear across the Northern Rivers, but has anyone spotted the much-loved Christmas beetle yet?

Three years ago The Northern Star reported on an apparent decline of Christmas beetles across the region while a foreign intruder, known as the Argentine scarab, thrived thanks to a lack of predators.

Yellow-brown beetles have again been seen swarming across the region.

Based on scientific descriptions of the Christmas beetle compared to the Argentine scarab, including both size and colour, beetles gathering so far this season have possibly been the non-native variety.

Famous for their shimmering green backs and abundance around Christmas time, Christmas beetles came from the Anoplognathus genus but not all 39 species wore green, creating confusion for non-scientists trying to pick between beetles.

"Christmas beetles range from 15-40mm in size and come in many colours," stated information from the Queensland Museum.

"Most are golden brown, but they can be green or black.

"Mostly active at night, Christmas beetles are often attracted to lights."

Associate Professor of Forest Science and Management at Southern Cross University, Doland Nichols, said adult beetles come out and damaged eucalypts around Christmas.

"They feed on mature leaves, you can identify the jagged pattern left behind," he said.

"Spotted gums are highly susceptible to damage."

Christmas beetles live most of their lives as larvae in the ground until rainfall prompted them to emerge as hungry beetles: they would then swarm to the nearest gum trees for food.

"They come out, fly around, mate and lay eggs, and die," said Dr Nichols.

Dr Nichols referred to an area "north west of Kyogle on the way to Queensland" as "a perfect storm" for the "deep defoliation" that can occur after a Christmas beetle swarm.

Dr Lawson indicated that land clearing had led to "an unbalanced situation" for Christmas beetles and gum trees.

"Depending on the age and health of trees, after four or five years of intense defoliation they'll gradually decline and die," said Dr Lawson.

He said that the emergence of Christmas beetles depended on weather conditions.

"Health of populations fluctuate from year to year around rainfall patterns and it can be localised.

"When it's dry populations go down because conditions in soil aren't favourable for the larvae."