scholarly journals Cost-benefit evaluation of management strategies for an invasive amphibian with a stage-structured model

NeoBiota ◽  
2021 ◽  
Vol 70 ◽  
pp. 87-105
Author(s):  
Giovanni Vimercati ◽  
Sarah J. Davies ◽  
Cang Hui ◽  
John Measey
Keyword(s):  
Population Size ◽  
Control Strategies ◽  
Spatial Scales ◽  
Management Strategies ◽  
Cape Town ◽  
Cost Benefit ◽  
Structured Populations ◽  
Structured Model ◽  
Benefit Evaluation ◽  
Initial Strategy

Management strategies for invasive populations should be designed to maximise efficacy and efficiency, i.e. to accomplish their goals while operating with the least resource consumption. This optimisation is often difficult to achieve in stage-structured populations, because costs, benefits and feasibility of removing individuals may vary with stage. We use a spatially-explicit stage-structured model to assess efficacy of past, present and alternative control strategies for invasive guttural toads, Sclerophrys gutturalis, in Cape Town. The strategies involve removal of variable proportions of individuals at different life-history stages and spatial scales. We also quantify the time necessary to implement each strategy as a proxy of financial resources and we correct strategy outcomes by implementation of time to estimate efficiency. We found that the strategy initially pursued in Cape Town, which did not target any specific stage, was less efficient than the present strategy, which prioritises adult removal. The initial strategy was particularly inefficient because it did not reduce the population size despite allocating consistent resources to remove eggs and tadpoles. We also found that such removal might be detrimental when applied at high levels. This counter-intuitive outcome is due to the ‘hydra effect’: an undesired increase in population size caused by removing individuals before overcompensatory density dependence. Strategies that exclusively remove adults ensure much greater management efficiency than those that also remove eggs and tadpoles. Available management resources should rather be allocated to increase the proportion of adult guttural toads that are removed or the spatial extent at which this removal is pursued.

Critical issues and new challenges for research and management of invasive plants in the Pacific Islands

2014 ◽  
Vol 20 (2) ◽  
pp. 146 ◽  
Author(s):  
Jean-Yves Meyer
Keyword(s):  
Pacific Islands ◽  
Cost Benefit Analysis ◽  
Control Strategies ◽  
Management Strategies ◽  
Cost Benefit ◽  
Terrestrial Ecosystems ◽  
Ecosystem Functions ◽  
Natural Habitats ◽  
Island Ecosystems ◽  
The Pacific

Invasive alien species are recognized as a major threat to island biodiversity and ecosystem functions worldwide, with well-documented, detrimental impacts on the native biota of Oceania. Despite their high number and rapid increase in the Pacific Islands, invasive alien plants (IAP) have received less attention by researchers, managers, and the general public compared to invasive animals (e.g., predatory mammals). Indeed, although lists of IAP in natural and agroecosystems have been set up in most island countries and territories, their ecological and socio-economical impacts are still not well documented and/or popularized. Very few IAP eradication successes have been reported, and postcontrol monitoring and cost-benefit analysis are often missing. Moreover, most of the published studies have been conducted in the Hawaiian and the Galápagos islands. This essay is a call for more research and management efforts on IAP in Oceania, especially in the small tropical Pacific Islands. Focal areas should not only include species bioecology, control strategies and methods and prioritization systems (including risk assessments), but also better understanding of island ecosystems functioning (e.g. forest dynamics and resilience), with the integration of past and present anthropogenic and natural disturbances. The importance of “novel” ecosystems, where natural habitats have been partially or totally modified by humans, and the potential effects of climate change on terrestrial ecosystems should be addressed, and new conservation and management strategies defined in the Pacific Islands, in order to try to halt biodiversity erosion in highly vulnerable island ecosystems.

Chemosensory genes in the head of Spodoptera litura larvae

2021 ◽  
pp. 1-10
Author(s):  
Lu-Lu Li ◽  
Ji-Wei Xu ◽  
Wei-Chen Yao ◽  
Hui-Hui Yang ◽  
Youssef Dewer ◽  
...  
Keyword(s):  
Spodoptera Litura ◽  
Phylogenetic Trees ◽  
Target Genes ◽  
Control Strategies ◽  
Insect Pest ◽  
Management Strategies ◽  
Food Sources ◽  
Larval Feeding ◽  
Chemosensory System ◽  
Chemosensory Genes

Abstract The tobacco cutworm Spodoptera litura (Lepidoptera: Noctuidae) is a polyphagous pest with a highly selective and sensitive chemosensory system involved in complex physiological behaviors such as searching for food sources, feeding, courtship, and oviposition. However, effective management strategies for controlling the insect pest populations under threshold levels are lacking. Therefore, there is an urgent need to formulate eco-friendly pest control strategies based on the disruption of the insect chemosensory system. In this study, we identified 158 putative chemosensory genes based on transcriptomic and genomic data for S. litura, including 45 odorant-binding proteins (OBPs, nine were new), 23 chemosensory proteins (CSPs), 60 odorant receptors (ORs, three were new), and 30 gustatory receptors (GRs, three were new), a number higher than those reported by previous transcriptome studies. Subsequently, we constructed phylogenetic trees based on these genes in moths and analyzed the dynamic expression of various genes in head capsules across larval instars using quantitative real-time polymerase chain reaction. Nine genes–SlitOBP8, SlitOBP9, SlitOBP25, SlitCSP1, SlitCSP7, SlitCSP18, SlitOR34, SlitGR240, and SlitGR242–were highly expressed in the heads of 3- to 5-day-old S. litura larvae. The genes differentially expressed in olfactory organs during larval development might play crucial roles in the chemosensory system of S. litura larvae. Our findings substantially expand the gene inventory for S. litura and present potential target genes for further studies on larval feeding in S. litura.

scholarly journals A Three-Pronged Approach to Studying Sublethal Insecticide Doses: Characterising Mosquito Fitness, Mosquito Biting Behaviour, and Human/Environmental Health Risks

Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 546
Author(s):  
Mara Moreno-Gómez ◽  
Rubén Bueno-Marí ◽  
Miguel. A. Miranda
Keyword(s):  
Environmental Health ◽  
Population Size ◽  
Mosquito Species ◽  
Management Strategies ◽  
Adult Mortality ◽  
Negative Control ◽  
Environmental Health Risks ◽  
Vector Management ◽  
Sublethal Doses ◽  
Biting Behaviour

Worldwide, pyrethroids are one of the most widely used insecticide classes. In addition to serving as personal protection products, they are also a key line of defence in integrated vector management programmes. Many studies have assessed the effects of sublethal pyrethroid doses on mosquito fitness and behaviour. However, much remains unknown about the biological, physiological, demographic, and behavioural effects on individual mosquitoes or mosquito populations when exposure occurs via spatial treatments. Here, females and males of two laboratory-reared mosquito species, Culex pipiens and Aedes albopictus, were exposed to five different treatments: three doses of the pyrethroid prallethrin, as well as an untreated and a negative control. The effects of each treatment on mosquito species, sex, adult mortality, fertility, F1 population size, and biting behaviour were also evaluated. To compare knockdown and mortality among treatments, Mantel–Cox log-rank tests were used. The results showed that sublethal doses reduced mosquito survival, influencing population size in the next generation. They also provided 100% protection to human hosts and presented relatively low risks to human and environmental health. These findings emphasise the need for additional studies that assess the benefits of using sublethal doses as part of mosquito management strategies.

The cost–benefit evaluation based on ecosystem services under different ecological restoration scenarios

2021 ◽  
Vol 193 (7) ◽  
Author(s):  
Mingqi Li ◽  
Shiliang Liu ◽  
Yixuan Liu ◽  
Yongxiu Sun ◽  
Fangfang Wang ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Ecological Restoration ◽  
Cost Benefit ◽  
Benefit Evaluation ◽  
The Cost

scholarly journals Occurrence, Impact on Agriculture, Human Health, and Management Strategies of Zearalenone in Food and Feed: A Review

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 92
Author(s):  
Dipendra Kumar Mahato ◽  
Sheetal Devi ◽  
Shikha Pandhi ◽  
Bharti Sharma ◽  
Kamlesh Kumar Maurya ◽  
...  
Keyword(s):  
Human Health ◽  
Control Strategies ◽  
Management Strategies ◽  
Structural Similarity ◽  
Fungal Metabolites ◽  
Natural Estrogens ◽  
Food And Feed ◽  
Feed Safety ◽  
And Control ◽  
Different Sources

Mycotoxins represent an assorted range of secondary fungal metabolites that extensively occur in numerous food and feed ingredients at any stage during pre- and post-harvest conditions. Zearalenone (ZEN), a mycotoxin categorized as a xenoestrogen poses structural similarity with natural estrogens that enables its binding to the estrogen receptors leading to hormonal misbalance and numerous reproductive diseases. ZEN is mainly found in crops belonging to temperate regions, primarily in maize and other cereal crops that form an important part of various food and feed. Because of the significant adverse effects of ZEN on both human and animal, there is an alarming need for effective detection, mitigation, and management strategies to assure food and feed safety and security. The present review tends to provide an updated overview of the different sources, occurrence and biosynthetic mechanisms of ZEN in various food and feed. It also provides insight to its harmful effects on human health and agriculture along with its effective detection, management, and control strategies.

A framework for the Integrated Assessment of SDG trade-offs in the Sundarbans Biosphere Reserve.

2021 ◽  
Author(s):  
Charlotte Marcinko ◽  
Robert Nicholls ◽  
Tim Daw ◽  
Sugata Hazra ◽  
Craig Hutton ◽  
...  
Keyword(s):  
Environmental Change ◽  
Integrated Assessment ◽  
Spatial Scales ◽  
Strong Dependence ◽  
Management Strategies ◽  
Rural Livelihoods ◽  
Biosphere Reserve ◽  
Integrated Analysis ◽  
Trade Offs ◽  
The Sundarbans

<p>The United Nations Sustainable Development Goals (SDGs) and their corresponding targets are significantly interconnected, with many interactions, synergies and trade-offs between individual goals across multiple temporal and spatial scales.  We propose a framework for the Integrated Assessment Modelling (IAM) of a complex deltaic socio-ecological system in order to analyse such SDG interactions. We focus on the Sundarbans Biosphere Reserve (SBR), India within the Ganges-Brahmaputra-Meghna Delta. It is densely populated with 4.4 million people (2011), high levels of poverty and a strong dependence on rural livelihoods. It is only 50 km from the growing megacity of Kolkata (about 15 million people in 2020). The area also includes the Indian portion of the world’s largest mangrove forest – the Sundarbans – hosting the iconic Bengal Tiger. Like all deltaic systems, this area is subject to multiple drivers of environmental change operating across different scales. The IAM framework is designed to investigate current and future trends in socio-environmental change and explore associated policy impacts, considering a broad range of sub-thematic SDG indicators. Integration is achieved through the soft coupling of multiple sub-models, knowledge and data of relevant environmental and socio-economic processes.  The following elements are explicitly considered: (1) agriculture; (2) aquaculture; (3) mangroves; (4) fisheries; and (5) multidimensional poverty. Key questions that can be addressed include the implications of changing monsoon patterns, trade-offs between agriculture and aquaculture, or the future of the Sundarbans mangroves under sea-level rise and different management strategies, including trade-offs with land use to the north.  The novel high-resolution analysis of SDG interactions allowed by the IAM will provide stakeholders and policy makers the opportunity to prioritize and explore the SDG targets that are most relevant to the SBR and provide a foundation for further integrated analysis.</p>

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