The Epidemiology of Plant Virus Disease: Towards a New Synthesis

Abstract

Epidemiology is the science of how disease develops in populations, with applications in human, animal and plant diseases. For plant diseases, epidemiology has developed as a quantitative science with the aims of describing, understanding and predicting epidemics, and intervening to mitigate their consequences in plant populations. Although the central focus of epidemiology is at the population level, it is often necessary to recognise the system hierarchies present by scaling down to the individual plant/cellular level and scaling up to the community/landscape level. This is particularly important for diseases caused by plant viruses, which in most cases are transmitted by arthropod vectors. This leads to range of virus-plant, virus-vector and vector-plant interactions giving a distinctive character to plant virus epidemiology (whilst recognising that some fungal, oomycete and bacterial pathogens are also vector-borne). These interactions have epidemiological, ecological and evolutionary consequences with implications for agronomic practices, pest and disease management, host resistance deployment, and the health of wild plant communities. Over the last two decades, there have been attempts to bring together these differing standpoints into a new synthesis, although this is more apparent for evolutionary and ecological approaches, perhaps reflecting the greater emphasis on shorter often annual time scales in epidemiological studies. It is argued here that incorporating an epidemiological perspective, specifically quantitative, into this developing synthesis will lead to new directions in plant virus research and disease management. This synthesis can serve to further consolidate and transform epidemiology as a key element in plant virus research.

Aphid‐borne viruses infecting cultivated watermelon and squash in Spain: Characterization of a variant of cucurbit aphid‐borne yellows virus (CABYV)

“…In conclusion, despite the extent of this new yellowing disease in watermelon and other cucurbit crops being unknown, our findings suggest that this novel CABYV variant may be currently threatening cucurbit crops. It is thus fundamental to consider that plant viral epidemics are often initiated and spread through different host plants and varieties, along with different agroecological practices that may alter the viral disease epidemiology (Moya‐Ruiz et al, 2021; Jeger, 2020; Juárez et al, 2019; Valverde et al, 2020). This exchange of viral diseases between overlapping crops at spatial/temporal scales could play an important role, as it may hinder the early detection of the disease.…”

“…Heterogeneous host genotype populations (i.e., different host plants and varieties of cucurbits along with particular agroecological practices) may alter the epidemiological patterns of viral diseases (De Moya‐Ruiz et al, 2021; Juárez et al, 2019; Valverde et al, 2020). Hence, the systematic monitoring of the occurrence of viral diseases and their causative agents, combined with ecological and quantitative epidemiological approaches, is essential to understand and mitigate their consequences on crops and natural ecosystems (Jeger, 2020; McLeish et al, 2020). In addition, the genetic and biological characterization of the emerging viruses increases our understanding of the ecological epidemiology of the diseases and could facilitate their early detection and prompt action for their control.…”

Global Plant Virus Disease Pandemics and Epidemics

“…These include deploying remote sensing in association with precision agriculture to forecast: (i) epidemics on local, regional or continental scales via satellites; (ii) epidemics in individual crops via lightweight unmanned aerial vehicles; and (iii) precisely where to target control measures [ 227 ]. The latest innovations in information systems and predictive modelling should also be harnessed to predict the spread of virus pandemics and epidemics, and deliver advice over control options, such as Internet-based Decision Support Systems [ 227 , 228 , 229 , 230 ]. In addition, it is important to understand the full range of diversity of each virus (or viruses within virus complexes) that causes a plant virus disease pandemic or major epidemic.…”

Modelling interference between vectors of non-persistently transmitted plant viruses to identify effective control strategies

“…Understanding NPT viruses spread is complex because experimentation is costly and difficult: symptoms may be difficult to detect and experimental trials in the vicinity of susceptible commercial crops may be restricted (Cunniffe et al, 2014;Picard et al, 2017). Mathematical models are thus particularly useful to provide complementary insights on virus spread (Jeger, 2020) 2017) developed a model to assess the contributions of vector life history traits (e.g. growth rates, fecundity, and longevity) and behavior (e.g.…”