Growth characteristics and pathogenic consequences of predominant entomopathogenic Yukon soil fungi Mortierella alpina and Penicillium expansum, and effectiveness of Met52®, against larvae of the winter tick, Dermacentor albipictus

The aim of the study was to evaluate the potential use of selected species of soil fungi (Fusarium oxysporum, F. sulphureum, F. verticillioides, and Penicillium expansum) for the bioregulation of the dispersive stages of a parasitic nematode – the large roundworm of pig (Ascaris suum). Experimental cultures containing A. suum eggs with soil fungi and control cultures without fungi were incubated at 26°C for 28 days. Microscopic observations of the developmental stages of the A. suum eggs (zygote, 2-8 blastomeres, morula/blastula, gastrula, and larva) were performed at 7, 14, 21, and 28 days. The API-ZYM test was used to semi-quantitatively determine the activity of 19 hydrolytic fungal enzymes. The cytotoxicity of the fungi was determined with a tetrazole salt MTT assay. Microscopic observations of A. suum eggs incubated in the presence of fungi up to day 28 did not show any signs of destruction to egg shells and/or penetration of the fungi into the eggs. The ovistatic effect of all tested fungi (F. sulphureum, P. expansum, F. verticillioides, and F. oxysporum; p<0.05) was seen only on the 7th day of incubation, whereas on the 14th day, only F. verticillioides and F. oxysporum showed an inhibitory effect on the embryogenesis of A. suum, and by the 28th day, only P. expansum. The API-ZYM test showed differences in the hydrolytic activity of the tested strains, while the MTT assay showed the high cytotoxicity of F. sulphureum, the moderate cytotoxicity of F. verticillioides and P. expansum, and the low cytotoxicity of F. oxysporum. Among the fungal strains studied, F. sulphureum showed the highest ovistatic effect, which may be related to its enzymatic activity and cytotoxicity.

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First records of Dermacentor albipictus larvae collected by flagging in Yukon, Canada

Parasites & Vectors ◽

10.1186/s13071-020-04425-3 ◽

2020 ◽

Vol 13 (1) ◽

Author(s):

Emily S. Chenery ◽

N. Jane Harms ◽

Nicholas E. Mandrak ◽

Péter K. Molnár

Keyword(s):

North America ◽

Life Stage ◽

Management Strategies ◽

Critical Event ◽

Larval Life ◽

Host Seeking ◽

Dermacentor Albipictus ◽

Questing Activity ◽

Winter Tick ◽

Whole Life Cycle

Abstract Background The winter tick (Dermacentor albipictus) has garnered significant attention throughout North America for its impact on wildlife health, and especially for moose (Alces alces), where high tick burdens may result in host hair loss, anemia, and can prove fatal. The environmental transmission of D. albipictus larvae to a host is a critical event that has direct impact on infestation success, yet in-field observations of this life stage are lacking. In Yukon, Canada, D. albipictus had previously been found on hosts, but its larval life stage had not been detected in the field, despite previous sampling attempts. Methods We sampled for D. albipictus larvae using traditional flagging methods in Ibex Valley and Braeburn, Yukon. Sites were sampled repeatedly for D. albipictus larvae by flagging from late August to end of October in 2018 and late August to end of November 2019. Results Larvae of D. albipictus were collected throughout Ibex Valley, at approximate densities ranging from 0.04 to 4236 larvae/100 m2. Larvae were present primarily on grassy vegetation on south-facing slopes in the Ibex Valley region and in Braeburn. Highest average larval numbers suggest peak questing activity was towards the end of September and beginning of October, as elsewhere in North America. Conclusions To the best of our knowledge, we report the first successful collection of the off-host, larval life stage of D. albipictus by flagging, north of 60° latitude in Yukon, Canada. These new observations provide critical information on the spatial distribution of the host-seeking life stage of D. albipictus and confirm that this species is completing its whole life cycle in southern Yukon. Understanding the environmental conditions where larvae spend their vulnerable period off-host in this northern location can inform both management strategies and projections of future range expansion which may occur with a changing climate.

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Vertical transmission of the entomopathogenic soil fungus Scopulariopsis brevicaulis as a contaminant of eggs in the winter tick, Dermacentor albipictus, collected from calf moose (New Hampshire, USA)

Mycology&#58 An International Journal on Fungal Biology ◽

10.1080/21501203.2019.1600062 ◽

2019 ◽

Vol 10 (3) ◽

pp. 174-181 ◽

Cited By ~ 1

Author(s):

Jay A. Yoder ◽

Benjamin M. Rodell ◽

Lucas A. Klever ◽

Cameron J. Dobrotka ◽

Peter J. Pekins

Keyword(s):

Vertical Transmission ◽

New Hampshire ◽

Soil Fungus ◽

Dermacentor Albipictus ◽

Scopulariopsis Brevicaulis ◽

Winter Tick

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Mortality assessment of moose (Alces alces) calves during successive years of winter tick (Dermacentor albipictus) epizootics in New Hampshire and Maine (USA)

Canadian Journal of Zoology ◽

10.1139/cjz-2018-0140 ◽

2019 ◽

Vol 97 (1) ◽

pp. 22-30 ◽

Cited By ~ 15

Author(s):

H. Jones ◽

P. Pekins ◽

L. Kantar ◽

I. Sidor ◽

D. Ellingwood ◽

...

Keyword(s):

Climate Change ◽

New Hampshire ◽

Alces Alces ◽

Histologic Examination ◽

Late Winter ◽

Winter Mortality ◽

Ecological Communities ◽

Dermacentor Albipictus ◽

Southern Fringe ◽

Winter Tick

Populations within ecological communities constantly fluctuate due to a multitude of interactions that can be influenced by climate change. Moose (Alces alces (Linnaeus, 1758)) populations in northern New Hampshire and western Maine, subunits of the largest regional moose population in the continental United States, are suspected to be declining due to increasing frequency of winter tick (Dermacentor albipictus Packard, 1869) epizootics that cause >50% late-winter mortality of 9- to 12-month-old calves. To investigate this hypothesis, we collected general health measurements of calves captured at two study sites in January 2014–2016 and subsequently performed field necropsies and histologic examination of tissues of those radio-marked calves that died during winter and spring. At capture, calves (n = 179) were in normal (66%) and thin (32%) physical condition with high infestations of winter ticks. Most (88%) mortalities (n = 125) were associated with moderate to severe infestations of winter ticks. Gross necropsies and histologic examination found high tick infestations, emaciation, anemia, and endoparasitism; lungworm (species of the genus Dictyocaulus Railliet and Henry, 1907) was also found in most (87%) calves. Three consecutive years (2014–2016) of winter tick epizootics is unprecedented in the region, rare in North America, and arguably reflects a host–parasite relationship strongly influenced by climate change at the southern fringe of moose habitat.

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Cytogenetics of Ticks (Acari: Ixodoidea). 10. Chromosomes of the Winter Tick, Dermacentor albipictus (Ixodidae)

Journal of Parasitology ◽

10.2307/3278162 ◽

1972 ◽

Vol 58 (6) ◽

pp. 1182

Author(s):

James H. Oliver ◽

Richard L. Osburn

Keyword(s):

Dermacentor Albipictus ◽

Winter Tick

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Sudden Mortality in Captive White-Tailed Deer With Atypical Infestation of Winter Tick

Journal of Medical Entomology ◽

10.1093/jme/tjab043 ◽

2021 ◽

Author(s):

Erika T Machtinger ◽

Hayley R Springer ◽

Jessica E Brown ◽

Pia U Olafson

Keyword(s):

Odocoileus Virginianus ◽

Physical Condition ◽

Clinical Symptoms ◽

Alces Alces ◽

Good Physical Condition ◽

Dermacentor Albipictus ◽

Central Pennsylvania ◽

Cervus Canadensis ◽

Winter Tick

Abstract In October 2020, three captive male white-tailed deer, Odocoileus virginianus [Zimmermann] (artiodactyla: Cervidae), were found dead in central Pennsylvania and a fourth was euthanized due to extreme lethargy. The deer presented with high burdens of Dermacentor albipictus (Packard) (Ixoda: Ixodidae) (winter tick). There were no other clinical symptoms and deer were in otherwise good physical condition with no observed alopecia. Winter tick epizootics have been associated with mortalities of moose, Alces alces [Linnaeus] (artiodactyla: cervidae), and more recently elk, Cervus canadensis [Erxleben] (artiodactyla: cervidae), in Pennsylvania, but have not been reported in white-tailed deer. Mild winters are favorable to winter ticks and deer producers and managers should be aware of possible infestations as a result.

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Reproduction of the winter tick, Dermacentor albipictus, under field conditions in Alberta, Canada

Canadian Journal of Zoology ◽

10.1139/z86-105 ◽

1986 ◽

Vol 64 (3) ◽

pp. 714-721 ◽

Cited By ~ 14

Author(s):

Mark L. Drew ◽

W. M. Samuel

Keyword(s):

Incubation Period ◽

Egg Production ◽

Field Conditions ◽

Temperature Dependent ◽

Habitat Types ◽

Timing Of Reproduction ◽

Lower Survival ◽

Dermacentor Albipictus ◽

Aspen Forest ◽

Winter Tick

Total egg production and timing of reproduction by engorged female winter ticks (Dermacentor albipictus) were studied in three habitat types (aspen forest, bog, and grassland) of central Alberta. Results for the aspen forest included lower survival of engorged females, a longer incubation period, fewer eggs hatched, and a lower survival of larvae. Presence of snow resulted in decreased survival of engorged females in all habitats. Onset of oviposition in the three habitats was synchronous (early June) and, possibly, stimulated by photoperiod. Incubation period appeared temperature dependent.

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Expression, inheritance, and linkage relationships among eight enzyme genes in Dermacentor albipictus (Packard) (Acarina: Ixodidae)

Genome ◽

10.1139/g87-044 ◽

1987 ◽

Vol 29 (2) ◽

pp. 253-256 ◽

Cited By ~ 1

Author(s):

Larry R. Hilburn ◽

Claudio Castillo

Keyword(s):

Quaternary Structure ◽

Starch Gel Electrophoresis ◽

Mendelian Genetics ◽

Glucose Phosphate ◽

Dermacentor Albipictus ◽

Starch Gel ◽

Quaternary Structures ◽

Winter Tick ◽

Linkage Relationships ◽

Significant Linkage

Starch gel electrophoresis was used to examine the inheritance, expression, and linkage relationships among eight enzyme genes in the winter tick, Dermacentor albipictus. A fructose-specific hexokinase (FHK), adenylate kinase (ADK), and two forms of aconitase (ACON-A, ACON-C) appeared to have monomeric quaternary structures. A glycylleucine peptidase (PEP), isocitrate dehydrogenase (IDH), and anodally migrating malate dehydrogenase (MDH-A) were apparently dimers. The quaternary structure of glucose phosphate isomerase (GPI) could not be determined because of the similarity in relative mobility of the two available electromorphs. The genes for GPI, FHK, and ADK are located on the X chromosome in the following order: Adk – 37.4 – Gpi – 24.6 – Fhk, with Adk – Fhk being 46.5 map units apart. The remaining five genes were autosomally inherited. Of the 10 possible paired combinations of these genes, only the data for two pairs, Idh–Mdh (44.5% recombinants) and Acon-A–Acon-C (46.4% recombinants), suggested statistically significant linkage. Key words: enzymes, electrophoresis, Mendelian genetics, Dermacentor albipictus, tick.

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