The arrival of the summer holidays in eastern Australia has traditionally been marked by the appearance of Christmas beetles, large iridescent beetles that get their name from their presence during the Christmas season. However, in recent years, there has been a perception that these insects are no longer arriving in high numbers. This has led to questions about the decline of Christmas beetle populations and whether it is related to climate change. To address this issue, insect scientists are working with the public to gather data and determine the health of Christmas beetle populations.
Christmas beetles are a group of large beetles primarily found in Australia, with 36 different species. They are most common along the east coast and are found throughout the continent except for the southwest. These beetles emerge in early summer, mate, and lay their eggs in the soil. The eggs hatch into larvae, known as “curl grubs,” which live in the soil for 1-2 years before transforming into their adult form. The adult beetles then dig their way out of the ground and start the cycle again.
While most Christmas beetles have iridescent coloring, there are variations in color among different species. Some are green or golden, while others have classic Christmas beetle coloring with flecks of iridescence on their tawny brown bodies. It’s important to note that Christmas beetles are often confused with other scarab beetles and native flower chafers.
Unfortunately, there is no long-term population data for Christmas beetles, so it is difficult to determine if there has been a decline. However, many people remember seeing more Christmas beetles in the past. To gather more information, a community science project called the Christmas Beetle Count has been launched. The public is encouraged to submit their sightings of Christmas beetles to an online database, which will help determine which species may be at risk of decline or extinction.
The Christmas Beetle Count has been successful so far, with over 8,000 sightings submitted by over 4,000 people across Australia. Some rare species that haven’t been seen in decades have been photographed, providing valuable information about their distribution and population health. However, it is still too early to determine if Christmas beetles have made a comeback in 2023. While there has been an increase in reported sightings compared to last year, more data is needed to draw any conclusive trends.
Christmas beetles are important for the ecosystem as they likely serve as a food source for many animals during a time when they are producing and raising their young. The larvae of Christmas beetles also play a role in aerating the soil and recycling organic matter. Like many insects, Christmas beetles are threatened by habitat loss, so conserving native bushland is crucial for their survival. These beetles are an iconic part of Australia’s natural heritage, just like koalas, platypuses, and kangaroos.