Beneficial invertebrates of dairy pastures in south-eastern Australia

Abstract

Context The Australian dairy industry largely relies on grass-based pastures to feed cattle, yet these pastures also host dynamic invertebrate communities that can damage or benefit pasture productivity. While Australian dairy managers have traditionally focused on invertebrates that damage pastures (i.e. pests), invertebrates that provide valuable ecosystem services by acting as natural enemies to pests or delivering other beneficial functions (e.g. nutrient cycling) have received less attention. Aim Surveying the natural enemies and other beneficial invertebrate communities in pastures across seven Australian dairy regions and to explore how environmental and farm management factors impact these. Method Fifty seven pastures samples were collected during spring and autumn over two years. In doing so, we identified and counted 2 661 315 invertebrates or invertebrate colonies. Key results We found natural enemies and other beneficial invertebrate communities have a similar taxonomic composition across regions, with a small number of taxa dominating all regions, and rainfall the most consistent environmental driver in the abundance of these dominant taxa. Conclusions Farm management strategies to maintain or promote existing communities of beneficial taxa will likely be similar across regions. Associations between invertebrate communities suggest pest communities may indirectly impact the abundance and/or diversity of natural enemies and other beneficial invertebrates. Implications Although still an early step, our findings provide important baseline information that can be used to provide dairy managers with strategies to promote communities of beneficial invertebrates, and consequently maximise the benefits these invertebrates provide.

Discovery of insecticide resistance in field‐collected populations of the aphid pest, Acyrthosiphon kondoi Shinji

“…46 Greater support of non-chemical control options can also provide alternative avenues to manage A. kondoi and reduce selection for insecticide resistance. For example, natural enemies (e.g., parasitoid wasps) provide a valuable biocontrol option for aphids, [63][64][65] yet Australian growers have little knowledge of the natural enemies that target A. kondoi (but see Milne 66 ). Alternatively, growers may use some crops (e.g., medics), where cultivars have been bred with plant resistance to A. kondoi.…”