Population growth rate of dry bulb mite, Aceria tulipae (Acariformes: Eriophyidae), on agriculturally important plants and implications for its taxonomic status

Dry bulb mite (DBM), Aceria tulipae, is an economically important mite with a worldwide distribution and a broad host range. As a generalist, it is the most important eriophyoid mite attacking bulbous plants such as garlic, onion and tulip. To date, DBM has been recorded on host plants belonging to the families Liliaceae, Amaryllidaceae, Melanthiaceae and Asparagaceae. However, a precise understanding of DBM host range is lacking as it is largely based on casual records of mites on plants, some of which may include accidental hosts. Moreover, the possible existence of cryptic species has not been considered. In this study the hypothesis that DBM may be a complex of distinct genetic lineages or cryptic species was tested by comparing the common barcode sequence marker mtDNA COI of specimens from several populations originating from the Netherlands and Poland. The population growth rate of DBM on seven agriculturally important plant species and on various parts of the garlic plant was also experimentally assessed in the laboratory. The results did not support the first hypothesis, and indicated that DBM populations originating from Poland and the Netherlands shared essentially the same genome. In addition, they indicated that DBM reached the highest population growth rate on leek and also displayed high growth rates on garlic, chive and red onion, whereas white onion and wheat were not colonized by the mites. Answering the question of whether DBM is a single polyphagous species rather than a complex of cryptic lineages is of particular importance since the misidentification of pests may lead to ineffective control strategies. Moreover, improved knowledge of DBM host range is essential for assessing risk to crops

Failure Analysis Results and Corrective Actions Implemented for the EMU 3011 Water in the Helmet Mishap

During EVA (Extravehicular Activity) No. 23 aboard the ISS (International Space Station) on 07/16/2013 water entered the EMU (Extravehicular Mobility Unit) helmet resulting in the termination of the EVA (Extravehicular Activity) approximately 1-hour after it began. It was estimated that 1.5-L of water had migrated up the ventilation loop into the helmet, adversely impacting the astronauts hearing, vision and verbal communication. Subsequent on-board testing and ground-based TT and E (Test, Tear-down and Evaluation) of the affected EMU hardware components led to the determination that the proximate cause of the mishap was blockage of all water separator drum holes with a mixture of silica and silicates. The blockages caused a failure of the water separator function which resulted in EMU cooling water spilling into the ventilation loop, around the circulating fan, and ultimately pushing into the helmet. The root cause of the failure was determined to be ground-processing short-comings of the ALCLR (Airlock Cooling Loop Recovery) Ion Filter Beds which led to various levels of contaminants being introduced into the Filters before they left the ground. Those contaminants were thereafter introduced into the EMU hardware on-orbit during ALCLR scrubbing operations. This paper summarizes the failure analysis results along with identified process, hardware and operational corrective actions that were implemented as a result of findings from this investigation

Failure Analysis Results and Corrective Actions Implemented for the Extravehicular Mobility Unit 3011 Water in the Helmet Mishap

Water entered the Extravehicular Mobility Unit (EMU) helmet during extravehicular activity (EVA) no. 23 aboard the International Space Station on July 16, 2013, resulting in the termination of the EVA approximately 1 hour after it began. It was estimated that 1.5 liters of water had migrated up the ventilation loop into the helmet, adversely impacting the astronaut's hearing, vision, and verbal communication. Subsequent on-board testing and ground-based test, tear-down, and evaluation of the affected EMU hardware components determined that the proximate cause of the mishap was blockage of all water separator drum holes with a mixture of silica and silicates. The blockages caused a failure of the water separator degassing function, which resulted in EMU cooling water spilling into the ventilation loop, migrating around the circulating fan, and ultimately pushing into the helmet. The root cause of the failure was determined to be ground-processing shortcomings of the Airlock Cooling Loop Recovery (ALCLR) Ion Filter Beds, which led to various levels of contaminants being introduced into the filters before they left the ground. Those contaminants were thereafter introduced into the EMU hardware on-orbit during ALCLR scrubbing operations. This paper summarizes the failure analysis results along with identified process, hardware, and operational corrective actions that were implemented as a result of findings from this investigation

The Interface Between Wheat and the Wheat Curl Mite, \u3ci\u3eAceria tosichella\u3c/i\u3e, the Primary Vector of Globally Important Viral Diseases

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

Change in abundance of three phytophagous mite species (Acari : Eriophyidae, Tetranychidae) on quackgrass in the presence of choke disease

Phytophagous mites and endophytic fungi may interact when sharing a host plant, potentially influencing one another’s growth or population dynamics; however, interactions between them are poorly known and remain largely unexplored. In this study, quantitative associations between three species of phytophagous mites and the endophytic fungus Epichloë bromicola Leuchtm. & Schardl (Clavicipitaceae, Ascomycotina) on quackgrass, Elymus repens (L.) Gould are reported. The mites’ abundance was assessed on field-collected grass shoots that were either exhibiting choke disease symptoms or without the fungus. Overall, the abundance of Tetranychus urticae and Aculodes mckenziei was significantly lower on quackgrass plants infected by E. bromicola compared to plants without the fungus. Conversely, populations of Abacarus hystrix were significantly larger on plants colonised by the fungus than on uninfected plants. Thus, the presence of this endophytic fungus may have divergent effects on different phytophagous mite species although the basis of these effects is not yet known

Cryptic speciation in the Acari: a function of species lifestyles or our ability to separate species?

There are approximately 55,000 described Acari species, accounting for almost half of all known Arachnida species, but total estimated Acari diversity is reckoned to be far greater. One important source of currently hidden Acari diversity is cryptic speciation, which poses challenges to taxonomists documenting biodiversity assessment as well as to researchers in medicine and agriculture. In this review, we revisit the subject of biodiversity in the Acari and investigate what is currently known about cryptic species within this group. Based on a thorough literature search, we show that the probability of occurrence of cryptic species is mainly related to the number of attempts made to detect them. The use of, both, DNA tools and bioassays significantly increased the probability of cryptic species detection. We did not confirm the generally-accepted idea that species lifestyle (i.e. free-living vs. symbiotic) affects the number of cryptic species. To increase detection of cryptic lineages and to understand the processes leading to cryptic speciation in Acari, integrative approaches including multivariate morphometrics, molecular tools, crossing, ecological assays, intensive sampling, and experimental evolution are recommended. We conclude that there is a demonstrable need for future investigations focusing on potentially hidden mite and tick species and addressing evolutionary mechanisms behind cryptic speciation within Acari

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

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

A New Metaculus Species (Acari: Eriophyoidea) on Diplotaxis tenuifolia (Brassicaceae) From Serbia: A Combined Description Using Morphology and DNA Barcode Data

A new species of eriophyoid mite, Metaculus diplotaxi n. sp. inhabiting Diplotaxis tenuifolia ( L.) DC., is described from Serbia. To investigate interspecific variability between Metaculus spp. on three different Brassicaceae host plants ( viz. D. tenuifolia, Lepidium latifolium ( L.), Isatis tinctoria ( L.)), we analyzed phenotypic variability of morphological traits and molecular sequences of the mitochondrial cytochrome oxidase subunit I ( MT- CO1). Discriminant analysis identified seven traits that significantly differentiate three Metaculus spp: M. lepidifolii, M. rapistri, and M. diplotaxi n. sp. Analysis of MT- CO1 sequences supported the results obtained from the analysis of morphometric features

A new Aculodes species (Prostigmata: Eriophyoidea: Eriophyidae) associated with medusahead, Taeniatherum caput-medusae (L.) Nevski (Poaceae)

A new species of plant mite (Acari: Eriophyidae) was discovered on medusahead (Taeniatherum caputmedusae), an annual grass that is native to central Asia and the Mediterranean Basin. It is invasive in western North America. Aculodes altamurgiensis sp. nov., is described here and differentiated from other Aculodes spp., on the basis of morphology. Its DNA fingerprinting was reported and compared with Aculodes mckenziei collected from Elymus repens and Bromus inermis. Pairwise comparison of MT-001 sequences between A. altamurgiensis sp. nov., and A. mckenziei revealed 20.2-21.5% genetic divergence between these congeneric species. First collected in Parco Nazionale dell'Alta Murgia in Apulia, Italy in 2014,A. altamurgiensis sp. nov., has been subsequently collected from medusahead in Serbia, Bulgaria, Iran and Turkey. Based on these data and on preliminary observations on the effects of the mite on plant growth, A. altamurgiensis sp. nov., is currently being investigated as a candidate biological control agent of medusahead

Strategic considerations for invasive species managers in the utilization of environmental DNA (eDNA): Steps for incorporating this powerful surveillance tool

Invasive species surveillance programs can utilize environmental DNA sampling and analysis to provide information on the presence of invasive species. Wider utilization of eDNA techniques for invasive species surveillance may be warranted. This paper covers topics directed towards invasive species managers and eDNA practitioners working at the intersection of eDNA techniques and invasive species surveillance. It provides background information on the utility of eDNA for invasive species management and points to various examples of its use across federal and international programs. It provides information on 1) why an invasive species manager should consider using eDNA, 2) deciding if eDNA can help with the manager’s surveillance needs, 3) important components to operational implementation, and 4) a high-level overview of the technical steps necessary for eDNA analysis. The goal of this paper is to assist invasive species managers in deciding if, when, and how to use eDNA for surveillance. If eDNA use is elected, the paper provides guidance on steps to ensure a clear understanding of the strengths and limitation of the methods and how results can be best utilized in the context of invasive species surveillance