Xiaomeng Qi¹

¹School of Bioscience, The University of Melbourne, Melbourne

Abstract:

Since the 1950s, chemical insecticides have been widely used as a primary control strategy for both agricultural and disease-vector pest species. However, the systematic and widespread use of insecticides in agriculture over the past 60 years is thought to contribute to an ‘insect apocalypse’. The non-target insect species poisoning has been known since the publication of ‘Silent Spring’ in the 1960s’ and is supported by recent genetic evidence. Specifically, studies show that insecticide resistance mutations are observed in natural populations of non-target species, such as Drosophila melanogaster. However, such genetic evidence is limited to only a few non-pest species. Here, we aim to assess the impact of insecticides on non-pest insect biodiversity around Australian horticulture. We have collected over 100 wild insect species across at least six orders from three main horticultural regions in Victoria: the Yarra Valley, the Goulburn Valley, and the Sunraysia region. We use a DNA meta-barcoding approach to classify species and screen them for canonical resistant mutations at multiple insecticide-resistant loci. Such mutations occur repeatedly in pest species and are an outstanding example of parallel evolution. Our research has validated previously reported resistance mutations in pest species and discovered potentially novel resistance mutations in non-pest species. Future work includes screening for adaptive genetic footprints around loci showing resistance in those non-pest species. Our work will not only contribute to current databases but will also establish a novel reference database for monitoring insecticide resistance in diverse insect species, linking species identification directly with insecticide resistance mutations.