Australian fruitspotting bugs, Amblypelta nitida Stål and A. lutescens lutescens Distant (Hemiptera: Coreidae), are major economic pests of macadamia nuts in Australia. They are also pests of approximately a dozen other tropical and subtropical horticultural crops, and minor pests of many more. They are endemic to the east and northern coastal regions of Australia and as such are distributed across the entire growing region of Australia's macadamia industry. Although the industry is reliant on synthetic pesticides for several major pests and diseases, including fruitspotting bugs, biological control of a major pest, the macadamia nutborer, Cryptophlebia ombrodelta Lower (Lepidoptera: Tortricidae), has been successful and is widely adopted. This success has set a precedent within the macadamia industry and provided incentive for research and development of other biological control agents for other important pests. In the early 1990s, a hymenopteran egg parasitoid, Anastatus sp. (Eupelmidae), was identified as having potential as a biological control agent for fruitspotting bugs in Australia, and in 2010, mass rearing began. No formal studies on Anastatus sp., apart from initial releases conducted after its discovery, had been done prior to this thesis.A study on the potential for conservation biological control of fruitspotting bugs in macadamia orchards using habitat management was conducted over two years in northern New South Wales.Traditionally, trees in macadamia orchards are spaced such that the orchard canopy closes over when the trees reach maturity, shading out any existing ground-cover vegetation. In recent years, macadamia growers have been encouraged to adopt wider spacing and/or pruning techniques to increase light into their orchards for improved tree health and nut production. In this situation, common practice is to grow the shade-tolerant sweet smother grass in the mid-row; this provides ground-cover but does not increase floral diversity. In this study, open mid-row canopies, with resident, weedy, flowering mid-row ground-cover vegetation, were compared to closed mid-row canopies with no ground-cover vegetation in terms of a) pest and beneficial invertebrate abundance, b) predation levels of sentinel A. nitida eggs and c) levels of nut damage by A. nitida. The results showed a stark contrast between 'light' and 'dark' orchards; open canopy orchards ('light' orchards) harboured a significantly higher abundance of beneficial invertebrates than denser canopy orchards ('dark' orchards), whereas in 'dark' orchards the abundance of a major pest, the macadamia lace bug, Ulonemia concava Drake (Hemiptera: Tingidae), was significantly higher.Not a single fruitspotting bug was sampled during this experiment; however, damage levels to nuts were significantly lower in 'light' orchards compared to 'dark' orchards. Levels of predation on ii sentinel A. nitida eggs were variable and did not show any clear pattern that could be attributed to orchard management type. In two field release experiments, the...

The dairy industry provides an important contribution to the Australian economy, but its productivity relies on grass pastures that suffer significant damage from invertebrate pests. Managing these pests remains a challenge as information on their abundance and impact is only available for a handful of taxa in a few Australian dairy regions. In this study, we undertook an extensive survey of above-and below-ground pest communities across seven dairy regions in south-eastern Australia by repeatedly sampling 57 paddocks in 2017 and 2018. We then applied energetic models to estimate the amount of metabolisable energy produced by pastures that are potentially consumed by pests. Our survey indicates that dairy farmers encounter a similar composition of above-ground pests in most sampled regions, with a few pests, especially Sminthurus viridis (lucerne flea) and Rhopalosiphum padi (bird cherry-oat aphid), dominating pest communities. Below-ground pests were more variable between regions and are more likely to require region-specific control strategies. Our energetic modelling suggests that pests consume a threefold greater percentage of metabolisable energy produced by pastures during autumn than spring. S. viridis and R. padi were among the most economically important pests across all regions and seasons, while other pests, including several species of scarabs and the small pointed snail, Prietocella barbara, were predicted to be particularly damaging in specific regions. Together, our field survey and energetic modelling provide baseline information to assist dairy farmers manage invertebrate pests and help guide future research in the Australian dairy industry.

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.

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