A Review of the Potential Use of Entomopathogenic Nematodes to Control Above-Ground Insect Pests in South Africa

Entomopathogenic nematodes (EPNs), of the families Steinernema and Heterorhabditis, are insectparasites that have been successfully used as biological control agents of soil-based insect pests on theNorth American and European continents. The success of nematodes as biological control agents of the soilstages of pest insects has led to research into their use for control of above-ground insect pests. Laboratorybasedstudies have shown exceptionally good control, in most cases, against such pests as mealybugs,codling moth and leaf miners. As the life stages of the above-ground insect pests have not co-evolvedtogether with those of EPNs, they are, generally, more susceptible than the soil-based life stages. However,EPNs are susceptible to desiccation and vulnerable to UV radiation, so that ensuring their survival beyondsoil environments is problematic. The impetus to avoid environmental stressors can cause EPNs to seeksheltered, cryptic habitats on foliage, where their target insect pest (such as mealybugs) may be found.The current paper provides an overview of information on the application of EPNs as a biocontrol agentfor the control of insect pests above ground and on foliage, with particular reference to research done inSouth Africa

Grapevine Leaf Application of Steinernema yirgalemense to Control Planococcus ficus in Semi-field Conditions

The vine mealybug, Planococcus ficus Signoret (Hemiptera: Pseudococcidae), is a key insect pest of South African grapevine. The ability of mealybugs to avoid or resist the action of chemical pesticides has led to the investigation of alternative control methods, such as the application of entomopathogenic nematodes (EPNs). However, EPN application faces challenges, due to the maladaptation of EPN species to aboveground conditions. In this study, the ability of adjuvants to improve the control of P. ficus in grapevine using an indigenous nematode species, Steinernema yirgalemense, was investigated. A trial was performed to assess EPN survival on grapevine foliage, when applied in the morning (high humidity / low temperature) compared with in the afternoon (high temperature / low humidity). In a semi-field trial, the combination ofadjuvants Zeba® and Nu-Film-P® resulted in 66% control of P. ficus after 48 h, compared to the use of Zeba® alone (43%), and EPNs alone (28%). Additionally, lower concentrations of EPNs showed predictably lower mortality rates of P. ficus. Significantly, higher EPN survival was recorded at each time interval in the morning, compared with the corresponding interval in the afternoon. This study demonstrates the ability of S. yirgalemense, when applied with adjuvants and at an appropriate time of day, to control P. ficus on grapevine, under semi-field conditions

Conducting a team-based multi-sited focused ethnography in primary care

© 2017 The Author(s). Focused ethnography is an applied and pragmatic form of ethnography that explores a specific social phenomenon as it occurs in everyday life. Based on the literature a problem-focused research question is formulated before the data collection. The data generation process targets key informants and situations so that relevant results on the pre-defined topic can be obtained within a relatively short time-span. As part of a theory based evaluation of alternative forms of consultation (such as video, phone and email) in primary care we used the focused ethnographic method in a multisite study in general practice across the UK. To date there is a gap in the literature on using focused ethnography in healthcare research. The aim of the paper is to build on the various methodological approaches in health services research by presenting the challenges and benefits we encountered whilst conducing a focused ethnography in British primary care. Our considerations are clustered under three headings: constructing a shared understanding, dividing the tasks within the team, and the functioning of the focused ethnographers within the broader multi-disciplinary team. As a result of using this approach we experienced several advantages, like the ability to collect focused data in several settings simultaneously within in a short time-span. Also, the sharing of experiences and interpretations between the researchers contributed to a more holistic understanding of the research topic. However, mechanisms need to be in place to facilitate and synthesise the observations, guide the analysis, and to ensure that all researchers feel engaged. Reflection, trust and flexibility among the team members were crucial to successfully adopt a team focused ethnographic approach. When used for policy focussed applied healthcare research a team-based multi-sited focused ethnography can uncover practices and understandings that would not be apparent through surveys or interviews alone. If conducted with care, it can provide timely findings within the fast moving context of healthcare policy and research

Strange particle production in 158 and 40 AA GeV/cc Pb-Pb and p-Be collisions

Results on strange particle production in Pb-Pb collisions at 158 and 40 $A$ GeV/$c$ beam momentum from the NA57 experiment at CERN SPS are presented. Particle yields and ratios are compared with those measured at RHIC. Strangeness enhancements with respect to p-Be reactions at the same beam momenta have been also measured: results about their dependence on centrality and collision energy are reported and discussed.Comment: Contribution to the proceedings of the "Hot Quarks 2004" Conference, July 18-24 2004, New Mexico, USA, submitted to Journal of Physics G 7 pages, 5 figure

Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

We show the distribution of SARS-CoV-2 genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three available genomic nomenclature systems for SARS-CoV-2 to all sequence data from the WHO European Region available during the COVID-19 pandemic until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation. We provide a comparison of the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2.Peer reviewe

Once a Batesian mimic, not always a Batesian mimic: mimic reverts back to ancestral phenotype when the model is absent

Batesian mimics gain protection from predation through the evolution of physical similarities to a model species that possesses anti-predator defences. This protection should not be effective in the absence of the model since the predator does not identify the mimic as potentially dangerous and both the model and the mimic are highly conspicuous. Thus, Batesian mimics should probably encounter strong predation pressure outside the geographical range of the model species. There are several documented examples of Batesian mimics occurring in locations without their models, but the evolutionary responses remain largely unidentified. A mimetic species has four alternative evolutionary responses to the loss of model presence. If predation is weak, it could maintain its mimetic signal. If predation is intense, it is widely presumed the mimic will go extinct. However, the mimic could also evolve a new colour pattern to mimic another model species or it could revert back to its ancestral, less conspicuous phenotype. We used molecular phylogenetic approaches to reconstruct and test the evolution of mimicry in the North American admiral butterflies (Limenitis: Nymphalidae). We confirmed that the more cryptic white-banded form is the ancestral phenotype of North American admiral butterflies. However, one species, Limenitis arthemis, evolved the black pipevine swallowtail mimetic form but later reverted to the white-banded more cryptic ancestral form. This character reversion is strongly correlated with the geographical absence of the model species and its host plant, but not the host plant distribution of L. arthemis. Our results support the prediction that a Batesian mimic does not persist in locations without its model, but it does not go extinct either. The mimic can revert back to its ancestral, less conspicuous form and persist