Impact of citrus thrips chemical treatments on the predatory mite Euseius tularensis

Abstract:  The impacts of four pesticides used for control of citrus thrips, Scirtothrips citri (Moulton), were evaluated in both field and laboratory populations of a predaceous mite, Euseius tularensis Congdon. Abamectin and chlorfenapyr had the least impact of pesticides evaluated on a field population of E. tularensis and predaceous mite levels mirrored those observed in the untreated control but at a slightly depressed level. Spinosad reduced predaceous mites somewhat but they recovered to 50% of the level in the untreated control by the end of the trial. Mite populations were low throughout the trial in plots treated with cyfluthrin. As an overall summary statistic, cumulative predator mite-days ranged from 73.6% of the level observed in the untreated control with abamectin to 67.1% with chlorfenapyr, 36.8% with spinosad and 11.7% with cyfluthrin. Three additional field trials confirmed abamectin's minimal impact. In laboratory studies of adult female mite mortality on field-weathered, pesticide-treated leaves, cyfluthrin caused high mortality on day 1 after treatment and all mites that were not killed were driven off leaf discs until day 21. When mites were placed on leaf discs 1 day after treatment with abamectin, spinosad, or chlorfenapyr, 67.5% of the mites died on chlorfenapyr discs. By 7 days after treatment, no material but cyfluthrin showed a significant impact. Implications to citrus integrated pest management are discussed.     

Harvesting induced fluctuations: insights from a threshold management policy

In this work, it is shown that in a deterministic context, a threshold policy can induce cyclic behavior in an otherwise exploited stable population. These dynamics ensue as a result of the combination of the degree of harvesting pressure and more protective threshold densities. Virtual equilibrium in variable structure systems plays a determinant role in this dynamical outcome.     

Managing Plant Resources: How Intensive Can it be?

Previous studies have shown there is a wide spectrum of incipient management practices between gathering and agriculture, that include resources commonly considered “wild.” Based on the study of 20 species used as foodstuffs in the community of Santa María Tecomavaca (Mexico), we evaluated nonagricultural management forms such as gathering, incipient nonselective management, incipient selective management and occasional ex situ cultivation to learn if they represent a gradient in the intensity of manipulation of a resource. The way in which the intensity of manipulation of a resource can vary as a function of cultural importance and the species’ biology was also analyzed. Using an index that measures the intensity of management of a resource, it has been established that the degree of intensity depends on: the specialization of the practices directed to the environment as well as to the individuals; the number of persons performing these practices; and the number of different practices taking place. The degree of management intensity is also a consequence of the joint action of cultural importance and of species’ biology.

Conflicts between humans over wildlife management: on the diversity of stakeholder attitudes and implications for conflict management

Conflicts involving wildlife are, in essence, often conflicts between human parties with differing wildlife management objectives. However, the study and management of wildlife conflicts often focuses on the ecological context without addressing disagreements between people over these objectives. This research uses quantitative approaches to examine actors’ views on a complex wildlife-related conflict: a raptor of conservation concern that impacts on game-bird management. Four dominant elements of the debate emerged from initial semi-structured interviews: perceptions of conflict related issues; perceptions of each other; perceived barriers to consensus within the debate; and assessment of proposed practical management solutions. A quantitative survey that built on these elements demonstrates the degree to which perceptions differ between groups and how local variation in these elements may be obscured in a regional or national level debate. The findings emphasise the importance of understanding the social issues involved in wildlife related conflicts if management aims are to be agreed and achieved.     

An Integrated Framework for Risk Management and Population Health

The traditional medical model of health and health policy development has focused on individuals and the role of medical care in preventing and treating disease and injury. Recent attention to health inequities and social determinants of health has raised the profile of population heath and evidence-based strategies for improving the health of whole populations. At the same time, risk science has emerged as an important new discipline for the assessment and management of risks to health. This article reviews historical developments in the fields of risk management and population health and proposes a joint population health risk management framework that integrates the key elements of both fields. Applying this integrated approach to managing population health risks will facilitate the development of evidence-based health policy. It will encourage a more systematic and comprehensive evaluation of population health issues and promote the use of a broader suite of interventions to reduce health risks and enhance population health status.     

Web-Based Data, Document, and Knowledge Management in Restoration Projects

This paper gives an introduction to composition, creation, and management of knowledge using a long‐term research project as an example. The concept and first experiences for a web‐based knowledge management system (KMS) of the regeneration process of the stream Ilm (Thuringia, Germany) are presented. From 1996 until 2005, this restoration ecology project investigated whether the river ecosystem can attain its natural state again and how the regeneration can be influenced. The web‐based content management system iZone, with an emphasis on information retrieval and feedback, was used to support the process of storage, retrieval, and visualization of existing information, several Ph.D. studies, and expert knowledge in the concluding phase of the research project. The resulting KMS at the moment stores 90 entries from 35 project scientists.     

Rivers in peril inside and outside protected areas: a systematic approach to conservation assessment of river ecosystems

This paper establishes a framework within which a rapid and pragmatic assessment of river ecosystems can be undertaken at a broad, subcontinental scale, highlighting some implications for achieving conservation of river biodiversity in water‐limited countries. The status of river ecosystems associated with main rivers in South Africa was assessed based on the extent to which each ecosystem had been altered from its natural condition. This requires consistent data on river integrity for the entire country, which was only available for main rivers; tributaries were thus excluded from the analyses. The state of main river ecosystems in South Africa is dire: 84% of the ecosystems are threatened, with a disturbing 54% critically endangered, 18% endangered, and 12% vulnerable. Protection levels were measured as the proportion of conservation target achieved within protected areas, where the conservation target was set as 20% of the total length of each river ecosystem. Sixteen of the 112 main river ecosystems are moderately to well represented within protected areas; the majority of the ecosystems have very low levels of representation, or are not represented at all within protected areas. Only 50% of rivers within protected areas are intact, but this is a higher proportion compared to rivers outside (28%), providing some of the first quantitative data on the positive role protected areas can play in conserving river ecosystems. This is also the first assessment of river ecosystems in South Africa to apply a similar approach to parallel assessments of terrestrial, marine, and estuarine ecosystems, and it revealed that main river ecosystems are in a critical state, far worse than terrestrial ecosystems. Ecosystem status is likely to differ with the inclusion of tributaries, since options may well exist for conserving critically endangered ecosystems in intact tributaries, which are generally less regulated than main rivers. This study highlights the importance of healthy tributaries for achieving river conservation targets, and the need for managing main rivers as conduits across the landscape to support ecological processes that depend on connectivity. We also highlight the need for a paradigm shift in the way protected areas are designated, as well as the need for integrated river basin management plans to include explicit conservation visions, targets, and strategies to ensure the conservation of freshwater ecosystems and the services they provide.     

Customary management as precautionary and adaptive principles for protecting coral reefs in Oceania

Marine conservation programs in Oceania are increasingly turning to precautionary and adaptive management, particularly approaches which emphasize local participation and customary management. Although the application of community-based natural resource management is widespread in the region, the full integration of local knowledge and practices into the design, implementation, and monitoring of community-based conservation programs has been limited. There is also little empirical data to show whether or not community-based conservation projects are meeting their stated objectives. This paper summarizes an integrated method for selecting Marine Protected Area (MPA) sites and presents empirical evidence that illustrates how an MPA that was largely conceived using indigenous ecological knowledge and existing sea tenure governance (i.e., customary management practices), as part of a regional precautionary and adaptive community-based management plan, is showing signs of biological and social success. More generally, the paper shows how hybrid natural and social research approaches in tandem with customary management for designing MPAs can protect coral reefs in Oceania.     

Osteopontin overexpression in breast cancer: knowledge gained and possible implications for clinical management

Osteopontin (OPN) is a secreted protein that is overexpressed in a number of human cancers, and has been associated with increased metastatic burden and poor prognosis in breast cancer patients. The OPN protein contains several conserved structural elements including heparin- and calcium-binding domains, a thrombin-cleavage site, a CD44 binding site, and two integrin-binding sites. Experimental studies have shown that the ability of OPN to interact with a diverse range of factors, including cell surface receptors (integrins, CD44), secreted proteases (matrix metalloproteinases, urokinase plasminogen activator), and growth factor/receptor pathways (TGFalpha/EGFR, HGF/Met) is central to its role in malignancy. These complex signaling interactions can result in changes in gene expression, which ultimately lead to alterations in cell properties involved in malignancy such as adhesion, migration, invasion, enhanced tumor cell survival, tumor angiogenesis, and metastasis. Therefore, OPN is not merely associated with cancer, but rather it plays a multi-faceted functional role via complex molecular cross-talk with other factors. This review will focus on the role of OPN in breast cancer, in particular on the malignancy-promoting aspects of OPN that may reveal opportunities for new approaches to the clinical management of breast cancer.     

Hierarchical Bayesian integrated model for estimating migratory bird harvest in Canada

The Canadian Wildlife Service (CWS) requires reliable estimates of the harvest of migratory game birds, including waterfowl, to effectively manage populations of these hunted species. The National Harvest Survey is an annual survey of hunters who purchase Canada's mandatory migratory game bird hunting permit, integrating information from a survey of hunting activity with information from a separate survey of species composition in the harvest. We used these survey data to estimate the number of birds harvested for each species and hunting activity metrics (e.g., number of active hunters, days spent hunting). The analytical methods used to generate these estimates have not changed since the survey was first designed in the early 1970s. We describe a new hierarchical Bayesian integrated model, which replaces the series of ratio estimators that comprised the old model. We are using this new model to generate estimates for migratory bird harvests as of the 2019–2020 hunting season, and to generate updated estimates for all earlier years. The hierarchical Bayesian model uses over-dispersed Poisson distributions to model mean hunter activity and harvest (zero-inflated Poisson and zero-truncated Poisson, respectively). It also includes multinomial distributions to model some key components (e.g., variation in harvest across periods of the hunting season, the species composition of the harvest within each of those periods, the age and sex composition in the harvests of a given species). We estimated the parameters of the Poisson and the multinomial distributions for each year as random effects using first-difference time-series. This time-series component allows the model to share information across years and reduces the sensitivity of the estimates to annual sampling noise. The new model estimates are generally very similar to those from the old model, particularly for the species that occur most commonly in the harvest, so the results do not suggest any major changes to harvest management decisions and regulations. Estimates for all species from the new model are more precise and less susceptible to annual sampling error, particularly for species that occur less commonly in the harvest (e.g., sea ducks, other species of conservation concern). This new model, with its hierarchical Bayesian framework, will also facilitate future improvements and elaborations, allowing the incorporation of prior information from the rich literature and knowledge in game bird management and biology.