Relationship between carrot weevil (Coleoptera: Curculionidae) infestation, damage, and planting dates of parsley (Apiaceae)

2002 ◽  
Vol 134 (1) ◽  
pp. 125-135 ◽  
Author(s):  
Angel N. Torres ◽  
Casey W. Hoy

AbstractSeasonal activity of carrot weevil, Listronotus oregonensis (LeConte), adults, eggs, larvae, and root feeding was studied in plots of parsley, Petroselinum crispum (Mill.) Nyman ex A.W. Hill, by sampling weekly from mid-May to the first week of September in 1998 and 1999. The initial population of overwintering adults, one complete generation, and at least a partial second generation were observed. The majority of eggs were deposited in June and most of the larvae were counted in July; the greatest damage was noticed from July onward. In both 1998 and 1999, the overall seasonal means of adults, eggs, larvae, and root feeding were significantly different among plots that were planted on different dates. Root feeding and all carrot weevil life stages sampled steadily decreased from the earliest to the latest planting. Most of the damage occurred in parsley plantings sown from late February until the third week of April. The number of eggs removed from parsley plants during the first cutting was significantly different among planting dates, but the impact of this removal may not be significant in infestation reduction. Results of this study will help parsley growers to target when control measures for carrot weevil will be most effective and which plantings are most likely to be damaged.

Parasitology ◽  
2018 ◽  
Vol 146 (6) ◽  
pp. 702-707 ◽  
Author(s):  
Annie-Ève Gagnon ◽  
Guy Boivin ◽  
Guy Bélair ◽  
Benjamin Mimee

AbstractBradynema listronoti is a parasitic nematode described from infected specimens of the carrot weevil Listronotus oregonensis. Prevalence of infection by B. listronoti under field conditions was followed over a period of 16 years in an untreated carrot field. Susceptibility of different carrot weevil life stages was evaluated as well as the impact of infection on fecundity and mortality. Gene expression in infected and uninfected carrot weevils was also compared to evaluate the impact of the parasite on the host transcriptome. Prevalence of B. listronoti in carrot weevil populations was sustained over the years ranging from 20 to 63%. All the weevil stages exposed to B. listronoti inoculum were susceptible to infection, larvae being more vulnerable (59 ± 8% infected) compared with pupae (4 ± 3% infected) and adults (7 ± 3% infected). The fecundity of infected female weevils was greatly reduced (60-fold) due to an inhibition of the maturation of the reproductive system. Transcriptomic analyses revealed that this parasitic castration may have been triggered by the inhibition of reproductive hormone production. The B. listronoti–L. oregonensis interaction represents a case of parasitic castration with a unique potential for biological control of an important pest of carrots.


1997 ◽  
Vol 129 (1) ◽  
pp. 187-194 ◽  
Author(s):  
A.B. Stevenson ◽  
E.S. Barszcz

AbstractThe carrot weevil, Listronotus oregonensis (LeConte), was monitored at 11 research or commercial carrot plantings at Holland Marsh, Kettleby, Ontario, using three methods, i.e. wooden plate (Boivin) traps to capture adults, carrot root sections placed in the soil to detect oviposition, and recording the numbers of adults present on carrot root sections. All three methods provided similar records of the seasonal pattern of adult activity. At most sites, thresholds used to determine the need for insecticide applications were reached or exceeded soon after the beginning of monitoring.There were significant linear relationships among the seasonal activity parameters generated by the three methods and between those parameters and percentage injury at harvest. Control programs that would have resulted from the use of each method are discussed.


1991 ◽  
Vol 123 (1) ◽  
pp. 63-76 ◽  
Author(s):  
D.X. Zhao ◽  
G. Boivin ◽  
R.K. Stewart

AbstractA simulation model was developed for the population dynamics of a carrot weevil, Listronotus oregonensis (LeConte), population on muck-grown carrots. The model includes mortality rates of eggs, larvae, and pupae for different sowing dates of carrots. It also incorporates the overwintered adult density, the temperature-dependent growth rates of the above-mentioned life stages, the age-, temperature-, and phenology-dependent oviposition rates, and the impact of an egg parasitoid, Anaphes sordidatus (Girault), on egg mortality rates. Model output was evaluated by comparing simulated results with observed results on the seasonal totals and time of population peaks of the egg and larval populations. The mean percentage differences between the simulated and observed seasonal egg totals were 3.1 ± 0.66 (SE) in 1987 and 1988, and 4.2 ± 0.05 in 1989. They were not statistically different. The mean percentage differences between the simulated and observed seasonal larval totals were 10 ± 3.33 in 1987 and 1988 and 29.8 ± 0.66 in 1989. Independent data sets (i.e. field data in 1989) showed a significant increase in the simulation error of the larval population. Sensitivity analysis indicated that A. sordidatus had a large influence on the population dynamics of L. oregonensis.


Author(s):  
Mihail Zver'kov

To the article the results of the theoretical and experimental researches are given on questions of estimates of the dynamic rate effect of raindrop impact on soil. The aim of this work was to analyze the current methods to determine the rate of artificial rain pressure on the soil for the assessment of splash erosion. There are the developed author’s method for calculation the pressure of artificial rain on the soil and the assessment of splash erosion. The study aims to the justification of evaluation methods and the obtaining of quantitative characteristics, prevention and elimination of accelerated (anthropogenic) erosion, the creation and the realization of the required erosion control measures. The paper considers the question of determining the pressure of artificial rain on the soil. At the moment of raindrops impact, there is the tension in the soil, which is called vertical effective pressure. It is noted that the impact of rain drops in the soil there are stresses called vertical effective pressure. The equation for calculation of vertical effective pressure is proposed in this study using the known spectrum of raindrops. Effective pressure was 1.4 Pa for the artificial rain by sprinkler machine «Fregat» and 5.9 Pa for long distance sprinkler DD-30. The article deals with a block diagram of the sequence for determining the effective pressure of rain drops on the soil. This diagram was created by the author’s method of calculation of the effective pressure of rain drops on the soil. The need for an integrated approach to the description of the artificial rain impact on the soil is noted. Various parameters characterizing drop erosion are considered. There are data about the mass of splashed soil in the irrigation of various irrigation machinery and installations. For example, the rate (mass) of splashed soil was 0.28…0.78 t/ha under irrigation sprinkler apparatus RACO 4260–55/701C in the conditions of the Ryazan region. The method allows examining the environmental impact of sprinkler techniques for analyzes of the pressure, caused by raindrops, on the soil. It can also be useful in determining the irrigation rate before the runoff for different types of sprinkler equipment and soil conditions.


2020 ◽  
Author(s):  
Lukman Olagoke ◽  
Ahmet E. Topcu

BACKGROUND COVID-19 represents a serious threat to both national health and economic systems. To curb this pandemic, the World Health Organization (WHO) issued a series of COVID-19 public safety guidelines. Different countries around the world initiated different measures in line with the WHO guidelines to mitigate and investigate the spread of COVID-19 in their territories. OBJECTIVE The aim of this paper is to quantitatively evaluate the effectiveness of these control measures using a data-centric approach. METHODS We begin with a simple text analysis of coronavirus-related articles and show that reports on similar outbreaks in the past strongly proposed similar control measures. This reaffirms the fact that these control measures are in order. Subsequently, we propose a simple performance statistic that quantifies general performance and performance under the different measures that were initiated. A density based clustering of based on performance statistic was carried out to group countries based on performance. RESULTS The performance statistic helps evaluate quantitatively the impact of COVID-19 control measures. Countries tend show variability in performance under different control measures. The performance statistic has negative correlation with cases of death which is a useful characteristics for COVID-19 control measure performance analysis. A web-based time-line visualization that enables comparison of performances and cases across continents and subregions is presented. CONCLUSIONS The performance metric is relevant for the analysis of the impact of COVID-19 control measures. This can help caregivers and policymakers identify effective control measures and reduce cases of death due to COVID-19. The interactive web visualizer provides easily digested and quick feedback to augment decision-making processes in the COVID-19 response measures evaluation. CLINICALTRIAL Not Applicable


Land ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 762
Author(s):  
Lei Han ◽  
Rui Chen ◽  
Zhao Liu ◽  
Shanshan Chang ◽  
Yonghua Zhao ◽  
...  

The environment of the urban fringe is complex and frangible. With the acceleration of industrialization and urbanization, the urban fringe has become the primary space for urban expansion, and the intense human activities create a high risk of potentially toxic element (PTE) pollution in the soil. In this study, 138 surface soil samples were collected from a region undergoing rapid urbanization and construction—Weinan, China. Concentrations of As, Pb, Cr, Cu, and Ni (Inductively Coupled Plasma Mass Spectrometry, ICP-MS) and Hg (Atomic Fluorescence Spectrometry, AFS) were measured. The Kriging interpolation method was used to create a visualization of the spatial distribution characteristics and to analyze the pollution sources of PTEs in the soil. The pollution status of PTEs in the soil was evaluated using the national environmental quality standards for soils in different types of land use. The results show that the content range of As fluctuated a small amount and the coefficient of variation is small and mainly comes from natural soil formation. The content of Cr, Cu, and Ni around the automobile repair factory, the prefabrication factory, and the building material factory increased due to the deposition of wear particles in the soil. A total of 13.99% of the land in the study area had Hg pollution, which was mainly distributed on category 1 development land and farmland. Chemical plants were the main pollution sources. The study area should strictly control the industrial pollution emissions, regulate the agricultural production, adjust the land use planning, and reduce the impact of pollution on human beings. Furthermore, we make targeted remediation suggestions for each specific land use type. These results are of theoretical significance, will be of practical value for the control of PTEs in soil, and will provide ecological environmental protection in the urban fringe throughout the urbanization process.


Author(s):  
Pietro De Luca ◽  
Antonella Bisogno ◽  
Vito Colacurcio ◽  
Pasquale Marra ◽  
Claudia Cassandro ◽  
...  

Abstract Background Since the spreading of SARS-CoV-2 from China, all deferrable medical activities have been suspended, to redirect resources for the management of COVID patients. The goal of this retrospective study was to investigate the impact of COVID-19 on head and neck cancers’ diagnosis in our Academic Hospital. Methods A retrospective analysis of patients treated for head and neck cancers between March 12 and November 1, 2020 was carried out, and we compared these data with the diagnoses of the same periods of the 5 previous years. Results 47 patients were included in this study. We observed a significative reduction in comparison with the same period of the previous 5 years. Conclusions Our findings suggest that the COVID-19 pandemic is associated with a decrease in the number of new H&N cancers diagnoses, and a substantial diagnostic delay can be attributable to COVID-19 control measures.


2021 ◽  
Vol 13 (1) ◽  
pp. 408
Author(s):  
Fernando Almeida-García ◽  
Rafael Cortés-Macías ◽  
Krzysztof Parzych

This study analyzes the role of residents in urban tourist destinations affected by the increase in tourist flows, which have generated various problems such as tourism, gentrification and the emergence of tourism as a threat to residents. The role of residents in tourist destinations has not been analyzed regularly during the development process of destinations. We study two cases of historic centers in European cities, with the aim of comparing tourism problems, which are common to most European urban destinations. This study was conducted by administering surveys amongst residents of these historic centers (378 in Málaga, Spain, and 380 in Gdansk, Poland). These cities show a similar demographic size and urban characteristics. This is the first comparative research on tourism-phobia and gentrification in destinations, a field of analysis that is still not studied much. We develop specific scales to measure gentrification and tourism-phobia; moreover, we study the impact of some tourist problems that affect residents (noise, dirt, occupation of public spaces, etc.), and we show the spatial distribution of tourism-phobia. The same analysis instruments are used for both cities. The results of this study show that the tourism-phobia situation is different in the analyzed destinations. It is more intense in the case of Málaga than in Gdansk. The two historic centers are especially affected by the processes of increased tourist flows and the growth of new forms of tourist accommodation. The research results show that the residents’ annoyance caused by tourism gentrification is more intense than tourism-phobia. Both case studies highlight the residents’ complaints regarding the inadequate management of problems by public stakeholders and control measures.


BMC Medicine ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Bimandra A. Djaafara ◽  
Charles Whittaker ◽  
Oliver J. Watson ◽  
Robert Verity ◽  
Nicholas F. Brazeau ◽  
...  

Abstract Background As in many countries, quantifying COVID-19 spread in Indonesia remains challenging due to testing limitations. In Java, non-pharmaceutical interventions (NPIs) were implemented throughout 2020. However, as a vaccination campaign launches, cases and deaths are rising across the island. Methods We used modelling to explore the extent to which data on burials in Jakarta using strict COVID-19 protocols (C19P) provide additional insight into the transmissibility of the disease, epidemic trajectory, and the impact of NPIs. We assess how implementation of NPIs in early 2021 will shape the epidemic during the period of likely vaccine rollout. Results C19P burial data in Jakarta suggest a death toll approximately 3.3 times higher than reported. Transmission estimates using these data suggest earlier, larger, and more sustained impact of NPIs. Measures to reduce sub-national spread, particularly during Ramadan, substantially mitigated spread to more vulnerable rural areas. Given current trajectory, daily cases and deaths are likely to increase in most regions as the vaccine is rolled out. Transmission may peak in early 2021 in Jakarta if current levels of control are maintained. However, relaxation of control measures is likely to lead to a subsequent resurgence in the absence of an effective vaccination campaign. Conclusions Syndromic measures of mortality provide a more complete picture of COVID-19 severity upon which to base decision-making. The high potential impact of the vaccine in Java is attributable to reductions in transmission to date and dependent on these being maintained. Increases in control in the relatively short-term will likely yield large, synergistic increases in vaccine impact.


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