By Helen Randerson, from Bulletin 4/2025, June
Where have all the Christmas Beetles gone?
On Wednesday 28 May, Glebe nature lovers made a beeline to Benledi to see and hear ecologist Tanya Latty’s presentation on how and why we should love and respect our diversity of local – but often unnoticed – insects and other invertebrates. Tanya Latty is Associate Professor in the School of Life and Environmental Sciences at the University of Sydney and Co-founder of Invertebrates Australia.[1] Her lecture was entitled, ‘Where have all the insects gone? Why insect declines matter and how people in cities can make a difference’.
Tanya outlined the many important roles that insects and invertebrates play – including as pollinators (30% of our food crops, including chocolate, are pollinated by insects), as general plant pollinators and conservators, as scavengers, in helping to break down waste, and in keeping crops healthier.
Although we’re living on a planet where insects and invertebrates make up approximately 95% of known animal species, we humans tend to overemphasise the importance of mammals, especially the ‘cute, cuddly ones’ – and we need to place greater value (and keep better data) on how our insects are doing. In fact, we lack data for most of the invertebrates in Australia.
As well as knowing very little about the basic ecology of our Australian-based insects, we have only given names to about 30% of them – and are losing many (to extinction) before we have even named them! And although we live on an insect planet of over 20,000 trillion ants, we don’t have much data on which insects are declining in number or are threatened species.
Since arriving from Canada approximately 20 years ago, Tanya has been researching Australian insects and invertebrates. She is familiar with the Glebe-Forest Lodge area (where there are nine species of hoverflies in Glebe and 40 species of native bees locally!). Tanya makes a point of always taking her camera with her, and she delighted the Benledi audience with her photos of colourful and unusual insects taken around Glebe, including the Glebe Foreshore.
Tanya suggested that a great place for spotting unusual insects is the railing alongside the path at Orphan School Creek. Tanya also stressed the importance for all of us in taking live photos and in sharing our sightings with others to encourage collaborative research, using the iNaturalist Australia app.
These live photos we take of insects can provide context and more knowledge than the dead specimens held in museums. For example, live photos may provide information about the plant the insect is feeding on. The iNaturalist app encourages information sharing and, through collaboration, helps build on existing knowledge – an example of the internet working at its best. Its data also adds to the national biodiversity database, the Atlas of Living Australia.
Tanya’s diverse research has included investigating pollinators of threatened midge orchids, researching the Social Velvet Worm, which was threatened by the ACT fires of 2019-2020 (called ‘cuddles’ because of the way they sleep together in a pile) and investigating the decline of the shiny, beautiful Christmas Beetle with its distinctive metallic colours.
Although they used to be a familiar sight around Christmas time, recently, 23% of people reported never seeing a Christmas beetle, and most of these people are under the age of 30. Nobody knows why, as there is no data. Because of this, Tanya described the Christmas Beetle as ‘like the canary in the coal mine’.
The many potential threats to invertebrates include lack of public interest, lack of scientific knowledge and lack of public knowledge. As to how we can make a difference, Tanya quoted the Senegalese forestry engineer Baba Dioum: ‘In the end, we will conserve only what we love; we will love only what we understand and we will understand only what we are taught.’
In Australia, 70% of people live in a major city and Tanya sees the cities as being part of the solution in helping people to love invertebrates. A large Tokyo study looked at which activities increased invertebrate biophilia. It found that gardening and being near nature (within 5 km of home) were important factors in developing people’s sense of an affinity with the natural world. (A hike out of the city was much less effective in rebuilding our relationship with nature.)
We can create insect-friendly cities by planting flowers – if you plant it, they will come.
We can plant flowers everywhere and take photos of the insects that land on them – as planting flowers attracts predatory arthropods (e.g., ladybirds, lacewings), which serve as a form of free pest control. We can share our photos, observations, collaborate and learn. We can share our memories of Christmas Beetles, we can give more respect to curl grubs, we can avoid broad-spectrum insecticides as well as eco insecticides (as they all impact scarabs). If we do the research and collect the data, we may learn to love and value our insects as much as we value our koalas.
At the conclusion of her lecture, Tanya answered many more of our questions as we all enjoyed a glass of wine and some sushi.
For more information about Christmas beetle research, see the website for the Christmas beetle count project, a collaboration between the University of Sydney and Invertebrates Australia.
[1] Editor’s note: Invertebrates Australia’s (IA) mission is ‘to provide an integrated scientific approach to the conservation and promotion of all Australian invertebrates.’ And their ‘vision is a future where invertebrates are appreciated and valued, and their biodiversity is sustained, across Australian lands and waters’. It’s worth having a look at their gorgeous website, even if you’re squeamish like me and don’t like looking too hard at creepy critters! You can sign up for quarterly updates and consider making a donation – IAis a registered charity.
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