scholarly journals Geographical distribution, climate adaptation and vector competence of the Eurasian hard tick Haemaphysalis concinna

2018 ◽  
Vol 9 (5) ◽  
pp. 1080-1089 ◽  
Author(s):  
Franz Rubel ◽  
Katharina Brugger ◽  
Melanie Walter ◽  
Janna R. Vogelgesang ◽  
Yuliya M. Didyk ◽  
...  
Keyword(s):  
Geographical Distribution ◽  
Climate Adaptation ◽  
Vector Competence ◽  
Hard Tick ◽  
Haemaphysalis Concinna

The hard-tick fauna of mainland Portugal (Acari: Ixodidae): an update on geographical distribution and known associations with hosts and pathogens

2011 ◽  
Vol 55 (1) ◽  
pp. 85-121 ◽  
Author(s):  
M. M. Santos-Silva ◽  
L. Beati ◽  
A. S. Santos ◽  
R. De Sousa ◽  
M. S. Núncio ◽  
...  
Keyword(s):  
Geographical Distribution ◽  
Hard Tick ◽  
Mainland Portugal

scholarly journals Borreliae Part 2: Borrelia Relapsing Fever Group and Unclassified Borrelia

Biology ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1117
Author(s):  
Giusto Trevisan ◽  
Marina Cinco ◽  
Sara Trevisini ◽  
Nicola di Meo ◽  
Maurizio Ruscio ◽  
...  
Keyword(s):  
Geographical Distribution ◽  
New World ◽  
Common Ancestor ◽  
Etiological Agent ◽  
Hard Tick ◽  
Soft Tick ◽  
Relapsing Fever ◽  
Old World ◽  
Pediculus Humanus ◽  
Candidate Species

Borreliae of the relapsing fever group (RFG) are heterogenous and can be divided mainly into three groups according to vectors, namely the soft-tick-borne relapsing fever (STBRF) Borreliae, the hard-tick-borne relapsing fever (HTBRF) Borreliae, the louse-borne relapsing fever (LBRF) Borreliae, and the avian relapsing fever ones. With respect to the geographical distribution, the STBRF Borreliae are further subdivided into Old World and New World strains. Except for the Avian relapsing fever group Borreliae, which cause avian spirochetosis, all the others share infectivity in humans. They are indeed the etiological agent of both endemic and epidemic forms of relapsing fever, causing high spirochaetemia and fever. Vectors are primarily soft ticks of Ornithodoros spp. in the STBRF group; hard ticks, notably Ixodes sp., Amblyomma sp., Dermacentor sp., and Rhipicephalus sp., in the HTBRF group; and the louse pediculus humanus humanus in the TBRF one. A recent hypothesis was supported for a common ancestor of RFG Borreliae, transmitted at the beginning by hard-body ticks. Accordingly, STBRF Borreliae switched to use soft-bodied ticks as a vector, which was followed by the use of lice by Borrelia recurrentis. There are also new candidate species of Borreliae, at present unclassified, which are also described in this review.

scholarly journals Vector competence of human-biting ticks Ixodes scapularis, Amblyomma americanum and Dermacentor variabilis for Powassan virus

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Rohit Sharma ◽  
Duncan W. Cozens ◽  
Philip M. Armstrong ◽  
Douglas E. Brackney
Keyword(s):  
Tick Species ◽  
Ixodes Scapularis ◽  
Vector Competence ◽  
Dermacentor Variabilis ◽  
Amblyomma Americanum ◽  
Hard Tick ◽  
Nymphal Stage ◽  
Tick Borne Encephalitis ◽  
Powassan Virus ◽  
The Usa

Abstract Background Powassan virus (POWV; genus Flavivirus) is the sole North American member of the tick-borne encephalitis sero-complex and an increasing public health threat in the USA. Maintained in nature by Ixodes spp. ticks, POWV has also been isolated from species of other hard tick genera, yet it is unclear if these species can serve as vectors. Dermacentor variabilis and Amblyomma americanum share geographic and ecologic overlap with Ixodes spp. ticks and POWV transmission foci, raising the possibility that POWV could become established in these tick species and leading to range expansion and increased human risk. Therefore, we assessed the competency of Ixodes scapularis, D. variabilis and A. americanum for POWV lineage II (POWV II). Methods Larvae from all three species were co-infested on POWV-infected Balb/c mice. The engorged larvae were allowed to molt to nymphs and screened for the presence of POWV II RNA by reverse transcription-qPCR. Eight infected nymphs from each species were allowed to individually feed on a naïve mouse. Mice were screened for the presence of POWV II RNA to determine infection status. Results The results demonstrated that larvae from all three tick species were able to efficiently acquire POWV II via feeding on viremic mice, maintain infection through molting and successively transmit POWV to naïve mice at the nymphal stage at comparable rates across all three species. Conclusions Our findings reveal that non-Ixodes tick species can serve as competent vectors for POWV and highlight the potential role of these species in the ecology and epidemiology of POWV. Future studies examining the possible implications of these findings on POWV epidemiology and the adaptability of POWV in these new vectors are warranted. Graphical abstract

TBE in China

2020 ◽  
Keyword(s):  
Western China ◽  
Ixodes Persulcatus ◽  
West China ◽  
North West ◽  
Haemaphysalis Concinna ◽  
Viral Subtype ◽  
Japanese Military ◽  
Natural Foci ◽  
Far Eastern ◽  
The Brain

The first TBE patients in China were reported in 1943, and the TBEV was isolated from the brain tissues of 2 patients in 1944 by Japanese military scientists,1 and from patients and ticks (Ixodes persulcatus and Haemaphysalis concinna) in 1952 by Chinese researchers.2 The Far Eastern viral subtype (TBEV-FE) is the endemic subtype that has been isolated from all 3 known natural foci (northeastern China, western China, and southwestern China).14 Recently a new “Himalayan subtype” of the TBEV (TBEV-HIM) was isolated from wild rodent Marmoata himalayana in the Qinghai-Tibet Plateau15. The main vector of the TBEV in China is I. persulcatus.3 One recent report suggests that the TBEV-SIB is prevalent in the Uygur region (North West China)13 but epidemiological modelling indicates that the TBEV may occur even widely all over China (Figure 3).4 Likely, the disease is often missed by clinicians due to a lack of the availability of specific diagnostic assays16.

Ecology and biogeography in the introduction to “De bestiis marinis” by Georg Wilhelm Steller

2019 ◽  
Vol 46 (1) ◽  
pp. 63-74
Author(s):  
Stefano Mattioli
Keyword(s):  
Body Size ◽  
Phenotypic Plasticity ◽  
Geographical Distribution ◽  
Functional Traits ◽  
Marine Mammals ◽  
Main Part ◽  
Wide Distribution ◽  
Restricted Range ◽  
Direct Influence ◽  
Modern Biology

The rediscovery of the original, unedited Latin manuscript of Georg Wilhelm Steller's “De bestiis marinis” (“On marine mammals”), first published in 1751, calls for a new translation into English. The main part of the treatise contains detailed descriptions of four marine mammals, but the introduction is devoted to more general issues, including innovative speculation on morphology, ecology and biogeography, anticipating arguments and concepts of modern biology. Steller noted early that climate and food have a direct influence on body size, pelage and functional traits of mammals, potentially affecting reversible changes (phenotypic plasticity). Feeding and other behavioural habits have an impact on the geographical distribution of mammals. Species with a broad diet tend to have a wide distribution, whereas animals with a narrow diet more likely have only a restricted range. According to Steller, both sea and land then still concealed countless animals unknown to science.

The Methow Beaver Project: the Challenges of an Ecosystem Services Experiment

2019 ◽  
Vol 3 (1) ◽  
pp. 1-14
Author(s):  
Philip Brick ◽  
Kent Woodruff
Keyword(s):  
Ecosystem Services ◽  
Climate Adaptation ◽  
Castor Canadensis ◽  
Water Storage ◽  
Climate Projections ◽  
High Mountain ◽  
Natural Resource Policy ◽  
Watershed Scale ◽  
Positive Role ◽  
Climate Conditions

This case explores the Methow Beaver Project (MBP), an ambitious experiment to restore beaver (Castor canadensis) to a high mountain watershed in Washington State, USA. The Pacific Northwest is already experiencing weather regimes consistent with longer term climate projections, which predict longer and drier summers and stronger and wetter winter storms. Ironically, this combination makes imperative more water storage in one of the most heavily dammed regions in the nation. Although the positive role that beaver can play in watershed enhancement has been well known for decades, no project has previously attempted to re-introduce beaver on a watershed scale with a rigorous monitoring protocol designed to document improved water storage and temperature conditions needed for human uses and aquatic species. While the MBP has demonstrated that beaver can be re-introduced on a watershed scale, it has been much more difficult to scientifically demonstrate positive changes in water retention and stream temperature, given hydrologic complexity, unprecedented fire and floods, and the fact that beaver are highly mobile. This case study can help environmental studies students and natural resource policy professionals think about the broader challenges of diffuse, ecosystem services approaches to climate adaptation. Beaver-produced watershed improvements will remain difficult to quantify and verify, and thus will likely remain less attractive to water planners than conventional storage dams. But as climate conditions put additional pressure on such infrastructure, it is worth considering how beaver might be employed to augment watershed storage capacity, even if this capacity is likely to remain at least in part inscrutable.

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