Problems, challenges and future of plant disease management: from an ecological point of view

Plant disease management faces ever-growing challenges due to： （i） increasing demands for total, safe and diverse foods to support the booming global population and its improving living standards; （ii） reducing production potential in agriculture due to competition for land in fertile areas and exhaustion of marginal arable lands; （iii） deteriorating ecology of agro-ecosystems and depletion of natural resources; and （iv） increased risk of disease epidemics resulting from agricultural intensification and monocultures. Future plant disease management should aim to strengthen food security for a stable society while simultaneously safeguarding the health of associated ecosystems and reducing dependency on natural resources. To achieve these multiple functionalities, sustainable plant disease management should place emphases on rational adaptation of resistance, avoidance, elimination and remediation strategies individually and collectively, guided by traits of specific host-pathogen associations using evolutionary ecology principles to create environmental （biotic and abiotic） conditions favorable for host growth and development while adverse to pathogen reproduction and evolution.

Neglected tropical diseases risk correlates with poverty and early ecosystem destruction

Background Neglected tropical diseases affect the most vulnerable populations and cause chronic and debilitating disorders.Socioeconomic vulnerability is a well-known and important determinant of neglected tropical diseases.For example,poverty and sanitation could influence parasite transmission.Nevertheless,the quantitative impact of socioeconomic conditions on disease transmission risk remains poorly explored.Methods This study investigated the role of socioeconomic variables in the predictive capacity of risk models of neglected tropical zoonoses using a decade of epidemiological data(2007–2018)from Brazil.Vector-borne diseases investigated in this study included dengue,malaria,Chagas disease,leishmaniasis,and Brazilian spotted fever,while directly-transmitted zoonotic diseases included schistosomiasis,leptospirosis,and hantaviruses.Environmental and socioeconomic predictors were combined with infectious disease data to build environmental and socioenvironmental sets of ecological niche models and their performances were compared.Results Socioeconomic variables were found to be as important as environmental variables in influencing the estimated likelihood of disease transmission across large spatial scales.The combination of socioeconomic and environmental variables improved overall model accuracy(or predictive power)by 10%on average(P<0.01),reaching a maximum of 18%in the case of dengue fever.Gross domestic product was the most important socioeconomic variable(37%relative variable importance,all individual models exhibited P<0.00),showing a decreasing relationship with disease indicating poverty as a major factor for disease transmission.Loss of natural vegetation cover between 2008 and 2018 was the most important environmental variable(42%relative variable importance,P<0.05)among environmental models,exhibiting a decreasing relationship with disease probability,showing that these diseases are especially prevalent in areas where natural ecosystem destruction is on its initial stages and lower when ecosystem destruction is on more advanced stages.Conclusions Destruction of natural ecosystems coupled with low income explain macro-scale neglected tropical and zoonotic disease probability in Brazil.Addition of socioeconomic variables improves transmission risk forecasts on tandem with environmental variables.Our results highlight that to efficiently address neglected tropical diseases,public health strategies must target both reduction of poverty and cessation of destruction of natural forests and savannas.

The Dicistroviridae: An Emerging Family of Invertebrate Viruses

Dicistroviruses comprise a newly characterized and rapidly expanding family of small RNA viruses of invertebrates. Several features of this virus group have attracted considerable research interest in recent years. In this review I provide an overview of the Dicistroviridae and describe progress made toward the understanding and practical application of dicistroviruses, including (i) construction of the first infectious clone of a dicistrovirus, (ii) use of the baculovirus expression system for production of an infectious dicistrovirus, (iii) the use of Drosophila C virus for analysis of host response to virus infection, and (iv) correlation of the presence of Israeli acute paralysis virus with honey bee colony collapse disorder. The potential use of dicistroviruses for insect pest management is also discussed. The structure, mechanism and practical use of the internal ribosome entry site (IRES) elements has recently been reviewed elsewhere.

Analysis on Green Development Strategy of Xinjiang Cotton

Through on-the-spot investigation and survey in Xinjiang cotton region and relevant data( containing statistical data,online information and government documents,etc.),the characteristics of water resource,wind-sand disaster,soil salinization,cotton diseases,insect pests and weeds in Xinjiang are studied. It is proposed reasons and specific programmes of green development strategy of Xinjiang cotton,and specific strategies contain ecological water supply,land desertification control,soil improvement,and ecological control of diseases,insect pests and weeds,thereby providing the support for sustainable development of Xinjiang cotton.

Does exploratory behavior or activity in a wild mouse explain susceptibility to virus infection？

Exploration and activity are often described as trade-offs between the fitness benefits of gathering information and resources, and the potential costs of increasing exposure to predators and para- sites. More exploratory individuals are predicted to have higher rates of parasitism, but this relationship has rarely been examined for virus infections in wild populations. Here, we used the multimammate mouse Mastomys natalensis to investigate the relationship between exploration, activity, and infection with Morogoro virus （MORV）. We characterized individual exploratory behav- ior （open field and novel object tests） and activity （trap diversity）, and quantified the relationship between these traits and infection status using linear regression. We found that M. natalensis expresses consistent individual differences, or personality types, in exploratory behavior （repeat- ability of 0.30, 95% CI： 0.21-0.36）. In addition, we found a significant contrasting effect of age on ex- ploration and activity where juveniles display higher exploration levels than adults, but lower field- activity. There was however no statistical evidence for a behavioral syndrome between these 2 traits. Contrary to our expectations, we found no correlation between MORV infection status and exploratory behavior or activity, which suggests that these behaviors may not increase exposure probability to MORV infection. This would further imply that variation in viral infection between individuals is not affected by between-individual variation in exploration and activity.

Can scavengers save zebras from anthrax? A modeling study

Namibia’s Etosha National Park(ENP)is home to many different animals such as lions,jackals,hyenas,zebras,elephants,etc.Each year,grazing animals are infected and die from anthrax caused by the bacteria Bacillus anthracis.This increases the number of carcasses in the park,which serve as food for scavengers such as jackals.This study investigates the interplay between anthrax transmission in zebras and the scavenging of zebra carcasses in ENP,using a deterministic mathematical model to describe the population dynamics.We strive to answer the following research questions:Under what conditions can the presence of scavengers control anthrax outbreaks in zebra populations=Does carcass production by anthrax help or hurt scavengers in the long term?Standard qualitative analysis techniques distinguished outcomes(stable equilibria)using reproduction numbers as threshold quantities.We found that,when scavengers feed on anthrax-laden carcasses,the scavengers help the zebras,by eliminating potential infection zones for the zebras.In this way they reduce anthrax’s spread by orders of magnitude.We also identify conditions under which the presence of anthrax benefits the scavengers,in terms of death-to-birth ratios for zebras,scavengers and anthrax.