The Interface Between Wheat and the Wheat Curl Mite, Aceria tosichella, the Primary Vector of Globally Important Viral Diseases

Abstract

Wheat production and sustainability are steadily threatened by pests and pathogens in both wealthy and developing countries. This review is focused on the wheat curl mite (WCM), Aceria tosichella, and its relationship with wheat. WCM is a major pest of wheat and other cereals and a vector of at least four damaging plant viruses (Wheat streak mosaic virus, High plains wheat mosaic virus, Brome streak mosaic virus, and Triticum mosaic virus). The WCM–virus pathosystem causes considerable yield losses worldwide and its severity increases significantly when mixed-virus infections occur. Chemical control strategies are largely ineffective because WCM occupies secluded niches on the plant, e.g., leaf sheaths or curled leaves in the whorl. The challenge of effectively managing this pest–virus complex is exacerbated by the existence of divergent WCM lineages that differ in host-colonization and virus-transmission abilities. We highlight research progress in mite ecology and virus epidemiology that affect management and development of cereal cultivars with WCM- and virus-resistance genes. We also address the challenge of avoiding both agronomically deleterious side effects and selection for field populations of WCM that can overcome these resistance genes. This report integrates the current state of knowledge of WCM–virus-plant interactions and addresses knowledge gaps regarding the mechanisms driving WCM infestation, viral epidemics, and plant responses. We discuss the potential application of molecular methods (e.g., transcriptomics, epigenetics, and whole-genome sequencing) to understand the chemical and cellular interface between the wheat plant and WCM–virus complexes.

Ecology and Epidemiology of Wheat Curl Mite and Mite-Transmissible Viruses in Colorado and Insights into the Wheat Virome

“…The variability in the WCM populations in a region can affect the prevalence and severity of virus infection (Wosula et al 2016) and responses to WCM resistance genes (Dhakal et al 2017;Harvey et al 1999). The WCM is a cryptic species complex that includes two globally distributed lineages: Type and Type 2 that are distinguishable using mitochondrial (mtDNA COI, 16S) and ribosomal (28S rDNA D2, ITS1-ITS2) marker and also differing in their host use patterns (generalization versus specialization) (Carew et al 2009;Hein et al 2012;Skoracka et al 2014;Skoracka et al 2018;Wosula et al 2016). In the current study, we used the ITS1 sequence to understand phylogenetic relationships among mite populations from this study plus populations from within the U.S including KS, SD, MT, TX, NE, and outside the U.S, such as France, Australia, Argentina and Brazil.…”

“…Among the top 10 wheat growing states, Colorado ranked 6 th in 2019 with 2,150,000 acres being planted and a yield of 49 bushels per acre resulting in total production of 98,000,000 bushels valued at $387,100,000 (USDA-NASS 2019). The wheat curl mite (WCM), Aceria tosichella Keifer (Acari: Eriophyidae) is a globally important pest affecting wheat production in the Americas, Europe, and Asia (Skoracka et al 2018). The mite causes direct damage by feeding, which can reduce cereal yield (Harvey et al 2000).…”

“…Worldwide, the WCM has been found to be a diverse species complex with numerous genetic lineages (Skoracka et al 2018). In North America however, only two genetically distinct genotypes of WCM have been characterized based on ribosomal ITS1 and mitochondrial Cytochrome oxidase I/II partial sequences: Type 1, initially identified from South Dakota, Kansas, Montana, Nebraska and Texas, and Type 2, from Nebraska (Hein et al 2012).…”

Barley Varieties Stoneham and Sydney Exhibit Mild Antibiosis and Antixenosis Resistance to the Wheat Curl Mite, Aceria tosichella (Keifer)

“…The wheat curl mite, Aceria tosichella Keifer, is the most important eriophyid pest of cereals in the world [1,2]. Foliage damage, head trapping, and transmission and spreading of devastating viruses are the most significant economic impacts of this mite on cereals [3].…”

“…Host plant resistance to A. tosichella and summer control of volunteer wheat are key components in the integrated pest management of this pest and associated viruses [2,15]. Reduced mite populations and virus transmission are valuable benefits resulting from A. tosichella-resistant wheat genotypes [16,17].…”