A genetic analysis reveals low prevalence of phytoplasma infection in Hyalesthes obsoletus Signoret, vector of 'bois noir', in SW-Germany

10.7287/peerj.preprints.732v2 ◽

2015 ◽

Author(s):

Gabriele Schiro ◽

Johannes Fahrentrapp ◽

Florian Hartig ◽

Bernd Panassiti

Keyword(s):

Temporal Distribution ◽

West Germany ◽

Economic Losses ◽

Type I ◽

Wine Production ◽

Bois Noir ◽

Vector Population ◽

Spatio Temporal ◽

Low Prevalence ◽

Hyalesthes Obsoletus

Bois Noir is a grapevine disease responsible for severe economic losses in wine production. Bois Noir is caused by Candidatus Phytoplasma solani, cell wall-less bacteria belonging to the taxonomic group 16Sr-XII-A. In Germany, they are known to be vectored from plant to plant by the cixiid Hyalesthes obsoletus, but so far the prevalence of the disease in the vector population, as well as its spatio-temporal distribution is poorly understood. We therefore analyzed infections of H. obsoletus collected in different vineyards in Baden (South-Western Germany) with quantitative real-time PCR. From 125 analyzed individuals, only five were infected with Ca. Phytoplasma solani. All infected individuals were colonized by Ca. Phytoplasma solani type I which is associated with the host plant Urtica dioica (stinging nettle). More research is needed to understand the reasons of this surprisingly low prevalence of Bois Noir in the population of H. obsoletus in South-West Germany.

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A genetic analysis reveals low prevalence of phytoplasma infection in Hyalesthes obsoletus Signoret, vector of 'bois noir', in SW-Germany

10.7287/peerj.preprints.732v1 ◽

2014 ◽

Author(s):

Gabriele Schiro ◽

Johannes Fahrentrapp ◽

Florian Hartig ◽

Bernd Panassiti

Keyword(s):

Temporal Distribution ◽

West Germany ◽

Economic Losses ◽

Type I ◽

Wine Production ◽

Bois Noir ◽

Vector Population ◽

Spatio Temporal ◽

Low Prevalence ◽

Hyalesthes Obsoletus

Bois Noir is a grapevine disease responsible for severe economic losses in wine production. Bois Noir is caused by Candidatus Phytoplasma solani, cell wall-less bacteria belonging to the taxonomic group 16Sr-XII-A. In Germany, they are known to be vectored from plant to plant by the cixiid Hyalesthes obsoletus, but so far the prevalence of the disease in the vector population, as well as its spatio-temporal distribution is poorly understood. We therefore analyzed infections of H. obsoletus collected in different vineyards in Baden (South-Western Germany) with quantitative real-time PCR. From 125 analyzed individuals, only five were infected with Ca. Phytoplasma solani. All infected individuals were colonized by Ca. Phytoplasma solani type I which is associated with the host plant Urtica dioica (stinging nettle). More research is needed to understand the reasons of this surprisingly low prevalence of Bois Noir in the population of H. obsoletus in South-West Germany.

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Relationships between Hyalesthes obsoletus, Its Herbaceous Hosts and Bois Noir Epidemiology in Northern Italian Vineyards

Insects ◽

10.3390/insects11090606 ◽

2020 ◽

Vol 11 (9) ◽

pp. 606

Author(s):

Nicola Mori ◽

Elena Cargnus ◽

Marta Martini ◽

Francesco Pavan

Keyword(s):

Host Plants ◽

Control Strategies ◽

Northern Italy ◽

Adult Survival ◽

Bois Noir ◽

Potted Plants ◽

Vector Population ◽

Vector Abundance ◽

The Relationship ◽

Hyalesthes Obsoletus

Hyalesthes obsoletus is the vector of “Candidatus Phytoplasma (Ca. P.) solani,” the causal agent of grapevine yellows Bois noir (BN). The relationships among the planthopper, its main herbaceous hosts as phytoplasma reservoirs (Convolvolus arvensis and Urtica dioica) and BN spreading were studied in northern Italy. In two areas the relationship between host plants and the phenology and survival of planthopper adults was investigated in potted plants and in field conditions. Moreover, H. obsoletus ecology, newly symptomatic grapevine occurrence and “Ca. P. solani” tuf-types’ presence were studied in two vineyards (2014–2019). An earlier occurrence of H. obsoletus adults on C. arvensis than U. dioica and better adult survival of the originating host were observed. When U. dioica was prevalent, the vector occurred almost exclusively along the ditch outside the vineyard. Hyalesthes obsoletus amount varied widely from year to year and nymphal mortality due to late frosts was supposed. In one vineyard, the amount of newly symptomatic grapevines was significantly correlated with vector abundance in the previous year. The “Ca. P. solani” tuf-type was influenced by vector population levels on the two hosts. Since the abundance of H. obsoletus populations on the two hosts influences BN epidemiology and dynamics and the “Ca. P. solani” tuf-type, this must be considered in BN control strategies.

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Systematic Review of Ticks and Tick-Borne Pathogens of Small Ruminants in Pakistan

Pathogens ◽

10.3390/pathogens9110937 ◽

2020 ◽

Vol 9 (11) ◽

pp. 937

Author(s):

Abdul Ghafar ◽

Tariq Abbas ◽

Abdul Rehman ◽

Zia-ud-Din Sandhu ◽

Alejandro Cabezas-Cruz ◽

...

Keyword(s):

Current Knowledge ◽

Small Ruminants ◽

Temporal Distribution ◽

Economic Losses ◽

Health Production ◽

Morphological Examination ◽

Comprehensive Information ◽

Spatio Temporal ◽

Tick Vectors ◽

And Control

Ticks and tick-borne diseases (TTBDis) are a major constraint to the health and production of small ruminants in Pakistan. Despite being the subject of intermittent studies over the past few decades, comprehensive information on the epidemiology and control of TTBDis is lacking. Herein, we have systematically reviewed the current knowledge on TTBDis of small ruminants in Pakistan. Critical appraisal of the selected 71 articles published between 1947 to 2020 revealed that morphological examination had been the most widely used method for the identification of TTBDis in Pakistan. Tick fauna comprise at least 40 species, mainly belonging to Haemaphysalis, Hyalomma and Rhipicephalus. The prevalence of ticks is the highest in summer (June–September) and it is also higher in goats than sheep. Anaplasma, Babesia and Theileria spp. are the major tick-borne pathogens (TBPs), and their prevalence is usually higher in sheep than goats. Spatio-temporal distribution, genetic diversity and control of ticks and TBPs of small ruminants as well as the competence of tick vectors for various TBPs remain to be explored. Therefore, coordinated and focused investigations are required to fill knowledge gaps in these areas to maximise the health, production and welfare of small ruminants and minimise economic losses associated with TTBDis in Pakistan.

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