The Survival and Reproduction of Rhopalosiphum padi (Hemiptera: Aphididae) on Different Plants: Exploring the Possible Host Range for a Serious Wheat Pest

2019 ◽  
Author(s):  
Xiong Peng ◽  
Lang Liu ◽  
Xin Guo ◽  
Peilei Wang ◽  
Chunman Song ◽  
...  
Keyword(s):  
Host Range ◽  
Insect Pests ◽  
Rhopalosiphum Padi ◽  
Management Strategies ◽  
Cyperus Rotundus ◽  
Effective Control ◽  
Survival And Reproduction ◽  
Chlorophytum Comosum ◽  
Fagopyrum Esculentum Moench

Abstract Rhopalosiphum padi (L.) is one of the most economically important pests of wheat worldwide; however, the host ranges of R. padi remain unclear. Particularly, it is unknown which plants R. padi can survive and reproduce on after the harvest of crops. The results revealed that the survival, developmental times, longevity, and fecundity of the aphid varied among the 13 Gramineae weeds, with the life-history parameters significantly differing. The virginoparae could survive long-term and reproduce on 11 of the 13 weeds. Gramineae weeds can possibly play a significant role in the buildup of R. padi populations as reservoirs. The virginoparae could survive long term and reproduce on Iris lactea Pall. var. chinensis (Fisch.) Koidz (Liliflorae: Iridaceae), Iris tectorum Maxim. (Liliflorae: Iridaceae), Cyperus rotundus L. (Cyperales: Cyperaceae), and Brassica oleracea L. var. capitata (Rhoeadales: Cruciferae), but not on Fagopyrum esculentum Moench (Polygonales: Polygonaceae), F. tataricum (L.) Gaertn. (Polygonales: Polygonaceae), Chlorophytum comosum (Thunb.) Baker (Liliflorae: Liliaceae), and Ophiopogon japonicas (Thunb.) Ker-Gawl (Liliflorae: Liliaceae). Rhopalosiphum padi can survive and reproduce on non-Gramineae plants of different families. Detailed host range information would be helpful for more effective control of insect pests. The design and implementation of sustainable pest management strategies should consider the aphid population on weeds and other host plants.

scholarly journals Farmer Knowledge of Climate Change Impacts and Adaptation Strategies in the Management of Vegetable Insect Pests in Zimbabwe

2017 ◽  
Vol 9 (12) ◽  
pp. 194
Author(s):  
Rumbidzai Debra Katsaruware-Chapoto ◽  
Paramu L. Mafongoya ◽  
Augustine Gubba
Keyword(s):  
Climate Change ◽  
Elevated Temperatures ◽  
Insect Pests ◽  
Insect Pest ◽  
Management Strategies ◽  
Climate Change Impacts ◽  
Effective Control ◽  
Vegetable Production ◽  
Farmer Knowledge ◽  
Climate Change Risk

Farmer knowledge of insect pests’ risks in a changing climate is important in managing insect pests’ incidence. A total of 250 vegetable farmers from 5 wards in Zimbabwe were sampled using a semi-structured questionnaire to assess their knowledge on climate change risk, its impact on vegetable insects pests and management strategies to reduce the increased incidence of insect pests. Focus group discussions, key informant interviews and field observations were also used. Droughts and elevated temperatures were perceived to have the greatest impact on vegetable insect pests resulting in their increased incidence. Aphids, cutworms and whiteflies were identified among the major pests that have increased. The majority (53%) of the farmers cited high vegetable losses from insect pests attack. All the respondents (100%) revealed the use of chemical insecticides during production of vegetables. A higher proportion (60%) perceived effective control, 34% perceived reduced efficacy and 6% were not sure of effectiveness of chemical insecticides. Management strategies to cope with the increasing insect pests and diseases on vegetable production also included planting insect resistant cultivars, certified seeds, increased frequency of application of synthetic insecticides, insecticide mixtures, use of more hazardous chemical insecticides and increasing the rates of application resulting in insecticide overuse. There is need for government to facilitate development and adoption of Integrated Insect Pest Management (IIPM) and raise awareness on avoiding overdependence on chemical insecticides. Modelling tools that support adaptation planning needs to be developed to forecast climate change risk and the resultant incidence of insect pests.

scholarly journals Investigating the Impact of Climate Warming on Phenology of Aphid Pests in China Using Long-Term Historical Data

Insects ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 167 ◽  
Author(s):  
Yangxue Wu ◽  
Junjie Li ◽  
Huanhuan Liu ◽  
Gexia Qiao ◽  
Xiaolei Huang
Keyword(s):  
Population Dynamics ◽  
Climate Warming ◽  
Historical Data ◽  
Insect Pests ◽  
Global Climate ◽  
Aphis Gossypii ◽  
Management Strategies ◽  
Individual Development ◽  
The Impact

Global climate warming has significant influence on individual development, population dynamics, and geographical distribution of many organisms, which has drawn much attention in recent years. As a large group of poikilotherms, insects whose life activities are closely linked with ambient temperature are supposed to be influenced by global warming. In order to test the consistency or difference of the effects of long-term climate warming on phytophagous insect pests in different geographical environments, this study collected historical data on the occurrence and population dynamics of three aphid pests (Myzus persicae, Aphis gossypii, and Sitobion avenae) in China, and systematically explored their phenological responses. We found that, during a period of about 60 years, in general, the first occurrence dates and the first migration dates of the three aphids almost moved earlier, while the end of the occurrence and the last migration dates were slightly delayed. However, these responses also represented geographical variation at a local scale. Basically, our results showed that the occurrence and migration seasons of these three aphid pests have been prolonged along with climate warming. This study based on historical literature data provides empirical evidence and valuable implications for understanding the impact of climate warming on insect pests and future management strategies.

Connecting Crop Nutrient Use Efficiency to Future Soil Productivity

2018 ◽  
Vol 102 (4) ◽  
pp. 8-10
Author(s):  
Fernando García ◽  
Andrés Grasso ◽  
María González Sanjuan ◽  
Adrián Correndo ◽  
Fernando Salvagiotti
Keyword(s):  
Nutrient Management ◽  
Nutrient Use Efficiency ◽  
Management Strategies ◽  
Crop Productivity ◽  
Soil Productivity ◽  
Nutrient Use ◽  
Grain Crop ◽  
Wide Scale ◽  
Use Efficiency

Trends over the past 25 years indicate that Argentina’s growth in its grain crop productivity has largely been supported by the depletion of the extensive fertility of its Pampean soils. Long-term research provides insight into sustainable nutrient management strategies ready for wide-scale adoption.

Petroclival meningiomas: long-term outcomes of multimodal treatments and management strategies based on 30 years of experience at a single institution

2020 ◽  
Vol 132 (6) ◽  
pp. 1675-1682 ◽  
Author(s):  
Jin Wook Kim ◽  
Hee-Won Jung ◽  
Yong Hwy Kim ◽  
Chul-Kee Park ◽  
Hyun-Tai Chung ◽  
...  
Keyword(s):  
Adjuvant Treatment ◽  
Management Strategies ◽  
Local Tumor Control ◽  
Tumor Control ◽  
Years Of Experience ◽  
Local Tumor ◽  
Long Term Outcomes ◽  
Single Institution ◽  
Petroclival Meningiomas

OBJECTIVEA thorough investigation of the long-term outcomes and chronological changes of multimodal treatments for petroclival meningiomas is required to establish optimal management strategies. The authors retrospectively reviewed the long-term clinical outcomes of patients with petroclival meningioma according to various treatments, including various surgical approaches, and they suggest treatment strategies based on 30 years of experience at a single institution.METHODSNinety-two patients with petroclival meningiomas were treated surgically at the authors’ institution from 1986 to 2015. Patient demographics, overall survival, local tumor control rates, and functional outcomes according to multimodal treatments, as well as chronological change in management strategies, were evaluated. The mean clinical and radiological follow-up periods were 121 months (range 1–368 months) and 105 months (range 1–348 months), respectively.RESULTSA posterior transpetrosal approach was most frequently selected and was followed in 44 patients (48%); a simple retrosigmoid approach, undertaken in 30 patients, was the second most common. The initial extent of resection and following adjuvant treatment modality were classified into 3 subgroups: gross-total resection (GTR) only in 13 patients; non-GTR treatment followed by adjuvant radiosurgery or radiation therapy (non-GTR+RS/RT) in 56 patients; and non-GTR without adjuvant treatment (non-GTR only) in 23 patients. The overall progression-free survival rate was 85.8% at 5 years and 81.2% at 10 years. Progression or recurrence rates according to each subgroup were 7.7%, 12.5%, and 30.4%, respectively.CONCLUSIONSThe authors’ preferred multimodal treatment strategy, that of planned incomplete resection and subsequent adjuvant radiosurgery, is a feasible option for the management of patients with large petroclival meningiomas, considering both local tumor control and postoperative quality of life.

Investigation of a New Approach to Predict Water Quality Extremes with a Case Study of Chemical Determinands in Stream Water

1991 ◽  
Vol 24 (6) ◽  
pp. 25-33
Author(s):  
A. J. Jakeman ◽  
P. G. Whitehead ◽  
A. Robson ◽  
J. A. Taylor ◽  
J. Bai
Keyword(s):  
Water Quality ◽  
Stream Water ◽  
Probability Distributions ◽  
Management Strategies ◽  
Hybrid Modelling ◽  
Trend Model ◽  
Environmental Extremes ◽  
Modelling Approach

The paper illustrates analysis of the assumptions of the statistical component of a hybrid modelling approach for predicting environmental extremes. This shows how to assess the applicability of the approach to water quality problems. The analysis involves data on stream acidity from the Birkenes catchment in Norway. The modelling approach is hybrid in that it uses: (1) a deterministic or process-based description to simulate (non-stationary) long term trend values of environmental variables, and (2) probability distributions which are superimposed on the trend values to characterise the frequency of shorter term concentrations. This permits assessment of management strategies and of sensitivity to climate variables by adjusting the values of major forcing variables in the trend model. Knowledge of the variability about the trend is provided by: (a) identification of an appropriate parametric form of the probability density function (pdf) of the environmental attribute (e.g. stream acidity variables) whose extremes are of interest, and (b) estimation of pdf parameters using the output of the trend model.

Mindtree: Tryst with the Corporate Control Market

2021 ◽  
pp. 227797792199190
Author(s):  
P. Bala Bhaskaran
Keyword(s):  
Capital Market ◽  
Corporate Control ◽  
Theory And Practice ◽  
Effective Control ◽  
Small Fish ◽  
Market Theory ◽  
Strategic Fit ◽  
Sequence Of Events ◽  
The Capital Market

The case is structured around the takeover of Mindtree Ltd (ML) by Larsen & Toubro Ltd (L&T) in June 2019. ML was founded and nurtured by a group of software professionals. In two decades, it had blossomed into an enterprise with global presence, US$ 1 billion turnover and a unique organizational culture. In a strange sequence of events, more than 20% of ML’s shares landed in L&T’s lap. L&T grabbed this opportunity and ran a systematic campaign to acquire the company. In about 100 days, L&T achieved its objective and got into the driver’s seat. The case traces the evolution of ML from a start-up to a publicly held company with global standing. It examines the circumstances and events leading to L&T getting the initial stake in the company; it examines the acquisition campaign of L&T and the response of the top management of ML. Research Questions Was there a strategic fit between ML and L&T? Were the capital market processes just and fair to all the stakeholders involved in the acquisition? Was L&T fair, prudent and sensitive in the acquisition process? Was Siddhartha loyal and fair to the founders of ML? Link to Theory The theoretical concepts that would enable a better comprehension of the case are: Analysis of strategic fit in M&A situations Capital market: Theory and practice Strategy for corporate control of an enterprise Significance of culture and ecosystem in knowledge organizations Phenomenon Studied Leadership styles relevant at different stages of evolution of an enterprise are different. A leader, at a given point of time, is successful when he is able to match his aspirations with the leadership needs of the enterprise at that point of time. The case can be used to demonstrate this phenomenon. Case Context Context of the case is that of an emerging infotech enterprise, coming under corporate raid and the unfolding capital market processes. The case highlights the shortcomings of the co-founders, leading to their unseating as also the sensitivity of the incoming management in handling the transition. Findings The case demonstrates the ability of the capital market to be fair to all stakeholders ensuring reward for competence and punishment for sloppiness. The case emphasizes the need for co-founders to have an effective strategy for corporate control; only then they could hope to achieve the long-term objectives. The case also illustrates the significance of sensitivity in handling softer issues like people and ecosystem in ensuring long-term success. Discussions At the outset, the case may appear to be that of a big fish swallowing a small fish. But a closer scrutiny would reveal the multiple dimensions of the case. Consider the role of Siddhartha. He seeded the idea of the company; he was a financier to it; he remained an investor in the company longer than most of the founders; when he pulled out, the co-founders could not hold the company together. Neither Siddhartha nor the co-founders had the far-sightedness to consolidate their shareholdings for effective control of the company into the future. This would trigger discussions on the differing roles of technocrats, managers, leaders and founders. Another point worthy of discussion would be: How were the co-founders choosing their leaders? Was it by rotation among themselves, or did they engage a set of criteria to identify an incumbent capable of leading a global company?

scholarly journals Contributions to Management Strategies in the NE Atlantic Regarding the Life History and Population Structure of a Key Deep-Sea Fish (Mora moro)

Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 522
Author(s):  
Régis Santos ◽  
Wendell Medeiros-Leal ◽  
Osman Crespo ◽  
Ana Novoa-Pabon ◽  
Mário Pinho
Keyword(s):  
Population Structure ◽  
Life History ◽  
Deep Sea ◽  
Management Strategies ◽  
Size Composition ◽  
Large Size ◽  
The Common ◽  
Fishing Impacts ◽  
Sea Fish

With the commercial fishery expansion to deeper waters, some vulnerable deep-sea species have been increasingly captured. To reduce the fishing impacts on these species, exploitation and management must be based on detailed and precise information about their biology. The common mora Mora moro has become the main deep-sea species caught by longliners in the Northeast Atlantic at depths between 600 and 1200 m. In the Azores, landings have more than doubled from the early 2000s to recent years. Despite its growing importance, its life history and population structure are poorly understood, and the current stock status has not been assessed. To better determine its distribution, biology, and long-term changes in abundance and size composition, this study analyzed a fishery-dependent and survey time series from the Azores. M. moro was found on mud and rock bottoms at depths below 300 m. A larger–deeper trend was observed, and females were larger and more abundant than males. The reproductive season took place from August to February. Abundance indices and mean sizes in the catch were marked by changes in fishing fleet operational behavior. M. moro is considered vulnerable to overfishing because it exhibits a long life span, a large size, slow growth, and a low natural mortality.

scholarly journals Coronary artery aneurysms: outcomes following medical, percutaneous interventional and surgical management

Open Heart ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. e001440
Author(s):  
Shameer Khubber ◽  
Rajdeep Chana ◽  
Chandramohan Meenakshisundaram ◽  
Kamal Dhaliwal ◽  
Mohomed Gad ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Surgical Management ◽  
Medical Management ◽  
Cox Regression ◽  
Artery Bypass ◽  
Management Strategies ◽  
Coronary Artery Aneurysms ◽  
Kaplan Meier

BackgroundCoronary artery aneurysms (CAAs) are increasingly diagnosed on coronary angiography; however, controversies persist regarding their optimal management. In the present study, we analysed the long-term outcomes of patients with CAAs following three different management strategies.MethodsWe performed a retrospective review of patient records with documented CAA diagnosis between 2000 and 2005. Patients were divided into three groups: medical management versus percutaneous coronary intervention (PCI) versus coronary artery bypass grafting (CABG). We analysed the rate of major cardiovascular and cerebrovascular events (MACCEs) over a period of 10 years.ResultsWe identified 458 patients with CAAs (mean age 78±10.5 years, 74.5% men) who received medical therapy (N=230) or underwent PCI (N=52) or CABG (N=176). The incidence of CAAs was 0.7% of the total catheterisation reports. The left anterior descending was the most common coronary artery involved (38%). The median follow-up time was 62 months. The total number of MACCE during follow-up was 155 (33.8%); 91 (39.6%) in the medical management group vs 46 (26.1%) in the CABG group vs 18 (34.6%) in the PCI group (p=0.02). Kaplan-Meier survival analysis showed that CABG was associated with better MACCE-free survival (p log-rank=0.03) than medical management. These results were confirmed on univariate Cox regression, but not multivariate regression (OR 0.773 (0.526 to 1.136); p=0.19). Both Kaplan-Meier survival and regression analyses showed that dual antiplatelet therapy (DAPT) and anticoagulation were not associated with significant improvement in MACCE rates.ConclusionOur analysis showed similar long-term MACCE risks in patients with CAA undergoing medical, percutaneous and surgical management. Further, DAPT and anticoagulation were not associated with significant benefits in terms of MACCE rates. These results should be interpreted with caution considering the small size and potential for selection bias and should be confirmed in large, randomised trials.

scholarly journals Bioactive Metabolites from the Endophytic Fungus Aspergillus sp. SPH2

2021 ◽  
Vol 7 (2) ◽  
pp. 109
Author(s):  
Viridiana Morales-Sánchez ◽  
Carmen E. Díaz ◽  
Elena Trujillo ◽  
Sonia A. Olmeda ◽  
Felix Valcarcel ◽  
...  
Keyword(s):  
Endophytic Fungus ◽  
Plant Pathogens ◽  
Insect Pests ◽  
Ethyl Acetate Extract ◽  
Rhopalosiphum Padi ◽  
Fungal Growth ◽  
Bioactive Metabolites ◽  
Endemic Plant ◽  
Antifungal Effects ◽  
Aspergillus Sp

In the current study, an ethyl acetate extract from the endophytic fungus Aspergillus sp. SPH2 isolated from the stem parts of the endemic plant Bethencourtia palmensis was screened for its biocontrol properties against plant pathogens (Fusarium moniliforme, Alternaria alternata, and Botrytis cinerea), insect pests (Spodoptera littoralis, Myzus persicae, Rhopalosiphum padi), plant parasites (Meloidogyne javanica), and ticks (Hyalomma lusitanicum). SPH2 gave extracts with strong fungicidal and ixodicidal effects at different fermentation times. The bioguided isolation of these extracts gave compounds 1–3. Mellein (1) showed strong ixodicidal effects and was also fungicidal. This is the first report on the ixodicidal effects of 1. Neoaspergillic acid (2) showed potent antifungal effects. Compound 2 appeared during the exponential phase of the fungal growth while neohydroxyaspergillic acid (3) appeared during the stationary phase, suggesting that 2 is the biosynthetic precursor of 3. The mycotoxin ochratoxin A was not detected under the fermentation conditions used in this work. Therefore, SPH2 could be a potential biotechnological tool for the production of ixodicidal extracts rich in mellein.

scholarly journals Tracking Changes on Soil Structure and Organic Carbon Sequestration after 30 Years of Different Tillage and Management Practices

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 291
Author(s):  
Ramón Bienes ◽  
Maria Jose Marques ◽  
Blanca Sastre ◽  
Andrés García-Díaz ◽  
Iris Esparza ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Organic Carbon ◽  
Management Practices ◽  
Management Strategies ◽  
Triticum Aestivum L ◽  
Field Trials ◽  
Conventional Tillage ◽  
Soil Parameters ◽  
Wilting Point

Long-term field trials are essential for monitoring the effects of sustainable land management strategies for adaptation and mitigation to climate change. The influence of more than thirty years of different management is analyzed on extensive crops under three tillage systems, conventional tillage (CT), minimum tillage (MT), and no-tillage (NT), and with two crop rotations, monoculture winter-wheat (Triticum aestivum L.) and wheat-vetch (Triticum aestivum L.-Vicia sativa L.), widely present in the center of Spain. The soil under NT experienced the largest change in organic carbon (SOC) sequestration, macroaggregate stability, and bulk density. In the MT and NT treatments, SOC content was still increasing after 32 years, being 26.5 and 32.2 Mg ha−1, respectively, compared to 20.8 Mg ha−1 in CT. The SOC stratification (ratio of SOC at the topsoil/SOC at the layer underneath), an indicator of soil conservation, increased with decreasing tillage intensity (2.32, 1.36, and 1.01 for NT, MT, and CT respectively). Tillage intensity affected the majority of soil parameters, except the water stable aggregates, infiltration, and porosity. The NT treatment increased available water, but only in monocropping. More water was retained at the permanent wilting point in NT treatments, which can be a disadvantage in dry periods of these edaphoclimatic conditions.

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