The future of smashed avocado might depend on patches of native vegetation preserved alongside farmland, as new Curtin research reveals the hidden role of these habitats in supporting the insects that keep crops – and brunch menus – thriving.
The research, published this week, found that insect communities in avocado orchards adjacent to native remnant vegetation foraged on more than twice as many plant species at times when crop flowering was limited, compared to those in orchards bordered by pasture.
Insects with more diverse food sources are more likely to survive and pollinate crops so this finding offers a potential clue to safeguarding global food security - as almost 10 billion people across the globe will require access to safe and nutritious food by 2050, meaning agricultural productivity will need to increase by 25 to 75 per cent.
Lead author Dr Joshua Kestel, who completed the research as part of his PhD at Curtin, said the research was particularly compelling because it had been traditionally difficult to quantify the diversity of pollen collected by entire insect communities – especially across vast agricultural landscapes.
"Using a novel method pioneered at Curtin University, we applied a cutting-edge biodiversity assessment technique – environmental DNA (eDNA) metabarcoding – to pan traps to identify the diversity of pollen transported by entire insect communities collected during sampling," Dr Kestel said.
"This approach allowed us to demonstrate that natural vegetation adjacent to orchards may enhance the resilience of insect communities, potentially contributing to greater food security."
Co-author Associate Professor Paul Nevill, from Curtin's School of Molecular and Life Sciences, said the research was significant because insects pollinate 75 per cent of all agricultural crops, yet many face extinction.
"In order to meet the food needs of the planet, diverse and healthy insect communities play a critical role in supporting essential ecosystem services such as pollination and the biological control of pests," Associate Professor Nevill said.
"In Australia alone, an estimated 320,000 insect species exist, yet only 35 per cent have been formally identified – and the plant resources many of them rely on remain largely unknown.
"By using sophisticated eDNA metabarcoding capable of detecting the trace of a single grain of pollen or even the footprint of a bee, we're helping to close these knowledge gaps and better understand how these insects might contribute to safeguarding global food security."
The researchers collected more than 2,000 insect specimens and identified more than 250 plant taxa from eDNA, including crops, weeds and native Australian flora.
The team recommended incorporating standardised biodiversity surveys into regular farm monitoring, protecting agroecosystems by recognising the value of natural vegetation and revegetating uncultivated land within orchards.
The full paper, titled 'Environmental DNA metabarcoding reveals complex interactions between natural capital in orchards: Insights into arthropod community dynamics and foraging diversity' and published in Environmental and Sustainability Indicators, can be viewed online here.
