Barbara I. P. Barratt

Urbanisation entails significant habitat loss leading to degradation of biodiversity and ecosystem services, and fragmented landscapes. Urban parks, which can take the form of large forest remnants, lawns, or a combination of the two, provide habitat for some species. The type of park and its location relative to other land uses affect the communities of species it supports. This study examined the composition of invertebrate communities, with emphasis on species richness and diversity of Coleoptera in parks along a gradient from low to high levels of urbanisation intensity, measured as the proportion of impervious surface within a surrounding buffer. The diversity of invertebrates differed only between parks at each end of the urbanisation gradient and a consistent, although non-significant, trend of increasing diversity from high to low intensity surrounding urbanisation. Parks situated closest to a large green space (> 30 ha in area; typically semi-natural, such as a reserve), had highest invertebrate richness, abundance and diversity. Increasing proportion of impervious surface had only a minor impact on invertebrate communities, likely due to the pre-selection of species tolerant to fragmentation and non-native vegetation. However, increasing urban densification will likely harm invertebrate diversity. Coleoptera communities were similar across all parks, although parks with patches of high-quality vegetation presented slightly different assemblages, potentially supporting less urban-tolerant species. While lawns are not completely sterile environments for invertebrates, enhancing vegetation heterogeneity in urban green spaces and creating green corridors for dispersal will improve invertebrate richness and diversity in urban parks, while retaining their amenity value.

The environment in which pollinators are reared may influence both their health and pollination performance. We compared the performance of 12 colonies of bumblebees ( Bombus terrestris ), each in their own simple (tomato monoculture) or florally diverse (tomatoes, borage, and lavender) arena inside a glasshouse. We found that colonies reared in florally diverse environments had a higher proportion of foragers overall and maintained slightly higher and less variable relative humidity inside the nest. Moreover, adding floral resources to a tomato crop resulted in increased total crop yield, whereas individual tomatoes reared in the simple monoculture environment were larger than those in the diverse. These results provide an important step in understanding the extent to which bumblebee health and flower-visiting behavior are influenced by the complexity of the foraging environment and how a diverse floral environment may enhance pollinator behavior toward a focal crop.

Natural grasslands are among the most threatened biomes on Earth. They are under pressure from land cover change including afforestation, farming intensification, invasive species, altered fire regimes, and soil amendments, all of which impact native biodiversity and ecosystem functioning. In Aotearoa New Zealand, tussock-dominated native grasslands expanded due to increased fire activity during waves of human settlement. These areas have subsequently been maintained as modified grasslands by agricultural pastoral land management practices and effects of introduced feral mammals.

New Zealand’s economically vital exotic pastures are unique in their low complexity making them highly susceptible to invasive pest species such as the Argentine stem weevil Listronotus bonariensis . This field‐based contribution further examined the ecology of the adult weevil and its parasitoid control agent Microctonus hyperodae. This included factors that affect field sampling accuracy, interpretation of population density and parasitism estimates. Compared to adult population estimates measured via turf flotation, suction sampling (G‐vac) showed c.30% under‐estimation of population densities while parasitism rates were over‐estimated by c.26%. The bionomic implications of the sampling biases are discussed as they relate to the recently observed sharp declines in L. bonariensis parasitism. The weevil’s field parasitism rates showed no relationship to population density again confirming the parasitoid’s very high host searching efficiency. This study also coincided with meteorological conditions (>30°C) that resulted in a very large L. bonariensis ‘swarming’ event. The mass emigration from the experimental plots left only a low residual population of parasitised weevils that typically do not fly. Therefore, measured L. bonariensis populations and their M. hyperodae parasitism levels cannot always be presumed to be solely the result of population dynamics in situ .

The third objective of the Convention on Biological Diversity, the fair and equitable sharing of benefits arising out of the use of genetic resources was further developed when the Nagoya Protocol on Access and Benefit Sharing came into effect in 2014. Interpretation of how this agreement is being implemented is wide-ranging and there are implications for biological control. A survey of biological control workers indicated that while some countries have facilitated access to biological control genetic resources, requirements in other countries have impeded biological control implementation. There was consensus that benefits to provider countries should be in the form of supporting local research communities. There was also agreement that the free use and exchange of biological control genetic resources has provided benefits to the global community, including to both providers and recipients of the agents. It is recommended that consideration of the free use and exchange principal should be a key element of Access and Benefit Sharing measures for the future.

The Nagoya Protocol on Access and Benefit Sharing (ABS) was implemented to further develop the third objective of the Convention on Biological Diversity, the fair and equitable sharing of benefits arising out of the utilization of genetic resources. Interpretation of this agreement is wide-ranging and there is concern that if ABS measures are poorly implemented biological control and the resultant public good will be greatly impeded. The ethos of multilateral use and exchange of genetic resources used in classical biological control will be particularly affected. In the spirit of the fair and equitable sharing of benefits arising out of the utilization of genetic resources, we propose a simple practical solution in the form of an international agreement on the use and exchange of classical biological control genetic resources.

Areas of uncertainty in the assessment of risks and benefits in applications for new biological control agents submitted to the regulator for proposed introduction into New Zealand were identified. This was done with the aim of informing future research priorities which might be able to address and reduce these areas of uncertainty to assist decision-making in the future. A sample of 20 applications received by the Environmental Protection Authority (EPA) between 2009 and 2019 were selected, with examples from weed and insect targets. Expressions of uncertainty were identified by applicants as well as the EPA staff assessment report of the application, and the final decision document prepared by the Authority’s committee. The most common risk uncertainties expressed were potential direct non-target effects (85%), cultural risks (75%), and whether there were existing (and possibly effective) natural enemies of the target already present in the new range (70%). Food web indirect effects and adequacy of host range testing were also mentioned in more than half of the case study applications and associated documents. For uncertainty relating to benefits, 75% of case studies mentioned uncertainty about the efficacy of the proposed biological control agent, or if the agent would be successful by establishing and spreading (60%). For several of the case studies questions were raised about the method of cost: benefit analyses that had been presented in the application. Recommendations for future research are presented.

The ecological impacts of invasive mammals are widely documented around the world. In New Zealand, fencing designed to exclude non-native mammals is used for conservation and restoration efforts. The Orokonui Ecosanctuary is a 307-hectare coastal Otago reserve (Dunedin, New Zealand) that is surrounded by mammal-exclusion fencing. The goal of the present study was to investigate how excluding mammals and including (native) animals inside the Orokonui Ecosanctuary fence has influenced ground- and litter-dwelling beetle (Coleoptera) abundance, diversity, and community composition. We hypothesised that beetle abundance, diversity, and community composition would be different whether the beetles sampled were from sites inside the fence or outside the fence. Beetles were extracted from the litter and soil of six sites (three inside, three outside) two times (once in winter, once in summer). The abundance, diversity, species composition, size distribution, and trophic guild distribution of beetles inside and outside the fence and between seasons were compared. Our results suggest that sites inside the fence harbour a greater abundance and diversity of beetles. We found a high abundance of native beetles both inside and outside the Orokonui Ecosanctuary’s fence. Further research may find evidence that the fenced sanctuary is providing a ‘halo effect’ whereby native beetles thriving within the Orokonui Ecosanctuary are spreading out into the surrounding landscape and also outcompeting introduced beetles.

Classical biological control, the introduction of natural enemies to new environments to control unwanted pests or weeds, is, despite numerous successful examples, associated with rising concerns about unwanted environmental impacts such as population decline of nontarget species. Recognition of these biosafety risks is globally increasing, and prerelease assessments of biological control agents (BCAs) have become more rigorous in many countries. We review the current approaches to risk assessment for BCAs as used in Australasia, Europe, and North America. Traditionally, these assessments focus on providing assurance about the specificity of a proposed BCA, generally via a list of suitable versus nonsuitable hosts determined through laboratory specificity tests (i.e., by determining the BCA's physiological host range). The outcome of interactions of proposed agents in the natural environment can differ from laboratory‐based predictions. Potential nontarget host testing may be incomplete, additional ecological barriers under field conditions may limit encounters between BCA and nontargets or reduce attack levels, and BCAs could disperse to habitats beyond those used by the target species and adversely affect nontarget species. We advocate for the adoption of more comprehensive, ecologically‐based, probabilistic risk assessment approaches to BCA introductions. An example is provided using a Bayesian network that can integrate information on probabilities and uncertainties of a BCA to spread and establish in new habitats, interact with nontarget species in these habitats, and eventually negatively impact the populations of these nontarget species. Our new model, Biocontrol Adverse Impact Probability Assessment, aims to be incorporated into a structured decision‐making framework to support national regulatory authorities.