control characterized by thoughtful analyses of project outcomes and recommendations to improve outcome assessments and increase the odds of success. As such, an optimistic prognosis for biological control is provided.

Through partitioning of ecological niches, several fungi are able to coexist on the same host crop. In (partial) absence of niche partitioning, competitive exclusion among fungi can occur. Competitive exclusion is one of the bases for biocontrol. We investigated fungal correlations, in terms of relative abundance of the fungi, in pre-harvest maize, as a natural ecosystem model. Internal mycobiome fungal relative abundance of maize was used to establish correlations. The maize had been harvested from dry and wet agro-ecological zones of Zambia. The relative abundances of the fungal genera were determined using DNA amplicon sequencing. For this study, positive or absence of correlations between fungal genera signified good niche partitioning (co-existence), whereas negative correlations signified poor niche partitioning and potential for competitive exclusion. When species compete within one niche (competitive exclusion), we may expect to detect higher levels of mycotoxins—since mycotoxins are considered antagonistic agents aimed at defending or invading an ecological niche. To estimate the importance of mycotoxins in competitive exclusion, we measured the influence of the fungal correlations on levels of fumonisin-B1 (FB1) in the maize. FB1 data were derived from a previous study on the maize, determined by HPLC. Results showed that Sarocladium and Stenocarpella had the strongest significant negative correlation with Fusarium, suggesting poor niche partitioning and potential for antagonism of these genera with Fusarium. Furthermore, higher levels of Stenocarpella resonated with lower levels of FB1 and vice versa. It was also observed that, when Sarocladium was in low abundance (< 10%), the frequency of detection of higher levels of FB1 (> 100 µg kg−1) in the pre-harvest maize was highest.

Improving success rates of classical weed biocontrol programs is an ongoing effort that requires a variety of different approaches. Previous assessments indicated biocontrol agent taxonomy and feeding characteristics and weed life history traits are associated with better control outcomes. We examined weed biocontrol releases for correlations between biocontrol agent and target weed traits associated with different levels of reported establishment and control. Data collated in the 5th edition of ‘Biological Control of Weeds: A World Catalogue of Agents and Their Target Weeds’ were used as the basis for this global analysis. Published literature was used to augment the catalog with data for eight biocontrol agent traits and four target weed traits. Biocontrol agent establishment and impact data were analyzed against these traits using generalized linear mixed models and categorical models, respectively. Analyses for biocontrol agent establishment reveal the following agent traits were correlated with a greater probability of establishment: being an internal feeder, feeding on above-ground plant tissues, multivoltine agents and agents that feed during both their adult and immature life stages. Insect taxon did not affect establishment except for the order Lepidoptera, which had the lowest establishment probability. For weed traits, those occurring in aquatic or riparian habitats were associated with a higher probability of biocontrol agent establishment. Regarding agent impact, using the definition categories in the catalog, agents feeding externally and on vegetative plant tissues, multivoltine agents and those with both adult and immature plant-feeding life stages were strongly correlated with greater impact. Perennials, reproducing only vegetatively and invading aquatic or riparian habitats were associated with greater biocontrol impact. Our findings could facilitate both the prioritization of invasive plants targeted for biocontrol and the selection of suitable biocontrol agent candidates, which should further improve biocontrol project outcomes.

The management of the brown stink bug, Euschistus heros Fabricius (Hemiptera: Pentatomidae), which is one of the main pests in soybean crops in Brazil, based on applied biological control programs, depends on detailed knowledge of the biological, behavioral parameters and capacity dispersion of control agents in agroecosystems. Only after approval of the reference forecast by the Ministry of Agriculture, livestock and supply for registration, a mandatory process in Brazil, is it possible to commercialize the biological agent. From this stage onwards, it is expected that studies will improve the optimization of technological packages to guarantee the efficiency

For reliable pest suppression, benefits of habitat management for natural enemies of agricultural pests need to be consistent over time. Unfortunately, most research projects allow only for one or two years of data collection. Here, we present a five-year study on effects of fungicide reduction and altered plant architecture on arthropod abundances and natural pest control in an experimental vineyard. The vineyard rows were divided into eight groups, half of which were trained in vertical shoot position (“trellis system”) and the other half as semi-minimal pruned hedge (“minimal pruning”). Every row was divided in three sections receiving three different plant protection intensities, respectively, with fungicides certified for organic viticulture. In each year we sampled arthropods from the grapevine canopy by standardized leaf collection and beat-sheet sampling, and exposed baits of a major grapevine pest (Lobesia botrana) to assess natural pest control. Arthropods, in particular predators, benefited from reduced fungicide sprayings and in turn promoted natural pest control. In contrast, effects of minimal pruning were less strong, and restricted to the leaf mesofauna, earwigs and leafhoppers. Across the five study years with their variable weather conditions, we conclude that the advantages of reduced fungicide sprayings in fungus-resistant varieties are consistent over time.

In Australia there are five weedy Sporobolus grass (WSG) species that heavily impact agricultural industries and native biodiversity. WSG have been the subject of several efforts to find host-specific pathogens with potential for classical and inundative biocontrol. Most of these studies are only discussed in unpublished reports or theses, so in this paper we synthesise the available peer-reviewed and ‘grey’ literature that discuss classical, augmentative and inundative biocontrol of WSG in Australia using fungal pathogens. We consider the hundreds of fungal pathogens previously isolated from Sporobolus hosts on an international and national scale. Of the pathogens investigated for WSG biocontrol previously, the only promising classical biocontrol agent was a smut fungus (Ustilago sporoboli-indici) from South Africa that is now present in Queensland and New South Wales, Australia. Its method of introduction to Australia is unknown. We hence discuss the history and potential for augmentative biocontrol of WSG using U. sporoboli-indici. Next, we summarise inundative biocontrol efforts. Several ascomycetes isolated from Australian WSG populations have been tested in this regard, including species of Nigrospora, Fusarium, Curvularia, Microdochium, Pestalotiopsis, and Neopestalotiopsis. However, a lack of host-specificity or efficacy subsequently precluded their further development, and potential improvements on those inundative biocontrol studies are discussed. Finally, we discuss a collection of endemic fungal taxa isolated from diseased Sporobolus in Australia, which are currently undergoing virulence, pathogenicity, and host-specificity screening as potential inundative biocontrol agents for WSG. Our intention is that the lessons learned from previous studies and summarised herein, will support ongoing development of WSG biocontrol agents in Australia, and more broadly, weed biocontrol using plant pathogens anywhere in the world.