Results 201 to 210 of about 5,332 (240)

Ultrastructure of Anaplasma marginale Theiler in Dermacentor andersoni Stiles and Dermacentor variabilis (Say)

American Journal of Veterinary Research, 1980
SUMMARY Cattle were inoculated with a Virginìa isolate of Anaplasma marginale Theiler and served as an infective source for laboratory-reared Dermacentor andersoni Stiles and D variabilis (Say) nymphs. Anaplasma marginale was demonstrated by electron microscopy in gut tissues of replete nymphal ticks and in unfed, incubated, and feeding adult ticks ...
K M, Kocan, J A, Hair, S A, Ewing
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Parthenogenetic Reproduction by Dermacentor variabilis (Acarina: Ixodidae)

Annals of the Entomological Society of America, 1971
Female American dog ticks, Dermacentor variabilis (Say), that fed on a bovine in the absence of males engorged, detached, and produced larvae parthenogenetically. These engorged virgin females weighed significantly less than mated females and also laid significantly smaller egg masses.
C. C. Dawkins, W. J. Gladney
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Transmission of Anaplasma marginale Theiler by Dermacentor andersoni Stiles and Dermacentor variabilis (Say)

American Journal of Veterinary Research, 1981
SUMMARY Cattle were inoculated with a Virginia isolate of Anaplasma marginale Theiler and served as an infective source for laboratory-reared Dermacentor andersoni Stiles and D variabilis (Say) nymphs. Following a molt and subsequent feeding of adult ticks on susceptible cows, transstadial transmission of A marginale occurred from cattle with ...
K M, Kocan, J A, Hair, S A, Ewing, L G, Stratton   +3 more
openaire   +2 more sources

Underwater survival in the dog tick Dermacentor variabilis (Acari:Ixodidae)

Journal of Insect Physiology, 2011
Ticks are blood-feeding arthropods known for their long survivability off the host. Although ticks are terrestrial, they can survive extended periods of time submerged underwater. A plastron is an alternative respiration system that can absorb oxygen from water via a thin layer of air trapped by hydrophobic hairs or other cuticular projections.
Philip Ryan, Laura J. Fielden, Lisa M. Knolhoff, Lisa M. Knolhoff, Susan M. Villarreal, Susan M. Villarreal   +5 more
openaire   +3 more sources

The Distribution in Oregon of Ixodes Pacificus, Dermacentor Andersoni, and Dermacentor Occidentalis with a Note on Dermacentor Variabilis (Acarina: Ixodidae)

Journal of Medical Entomology, 1977
Numerous tick collections from areas throughout Oregon between 1967 and 1975 have clarified the distribution of 3 man-biting species, Ixodes pacificus, Dermacentor andersoni , and D. occidentalis . Additional unpublished Oregon records at the Rocky Mountain Laboratory are included (a total of 11,839 ticks) to give full county (spatial) and monthly ...
Emmett R. Easton, Carleton M. Clifford, James E. Keirans, Robert A. Gresbrink   +3 more
openaire   +3 more sources

Absence of Assembly Pheromones in the Hard Ticks Dermacentor variabilis and Dermacentor andersoni (Acari: Ixodidae)

Journal of Medical Entomology, 1987
There was no evidence of response to an assembly pheromone when male and female Dermacentor variabilis (Say) and Dermacentor andersoni Stiles were exposed in petri dish assays to filter paper circles contaminated by other ticks (either conspecific or heterospecific), hexane extracts of ticks, tick feces, or tick excreta. These ticks did not assemble in
Sandra A. Allan, DeMar Taylor, James S. Phillips, Daniel E. Sonenshine   +3 more
openaire   +3 more sources

Persistence of colonies of Anaplasma marginale in overwintering Dermacentor variabilis

American Journal of Veterinary Research, 1987
SUMMARY Dermacentor variabilis were infected as nymphs with Anaplasma marginale by allowing the ticks to feed on a single infected donor calf. Two weeks after molting to the adult stage, the ticks were allotted into 1 of 3 groups and were allowed to overwinter at room temperature (25 C) in the laboratory (group 1), cold storage (4.5 C) in the ...
T M, Logan, K M, Kocan, W, Edwards, J A, Hair, P L, Claypool, S A, Ewing   +5 more
openaire   +2 more sources

Marking Dermacentor variabilis (Acari: Ixodidae) with Rubidium

Journal of Medical Entomology, 1994
Studies were conducted to determine the feasibility of marking Dermacentor variabilis (Say) with the alkali metal rubidium (Rb) by feeding larvae on mice that were injected with rubidium chloride (RbCl). Newly molted nymphs that fed as larvae for 2 to 5 d on RbCl-injected mice contained approximately 660 parts per billion (ppb) of Rb, whereas nymphs ...
openaire   +3 more sources

Attempted Ehrlichia risticii Transmission with Dermacentor variabilis (Acari: Ixodidae)

Journal of Medical Entomology, 1990
Larval Dermacentor variabilis (Say) (n = 327) were fed on Balb/C mice inoculated with Ehrlichia risticii, the etiologic agent of equine monocytic ehrlichiosis (Potomac horse fever). All mice displayed clinical signs of E. risticii infection at the time of feeding. After molting, resulting nymphs (n = 74) were fed on susceptible mice.
Robin B. Gager, William L. Nicholson, Jay F. Levine, Michael G. Levy   +3 more
openaire   +3 more sources

Hemocytic encapsulation of implants in the tickDermacentor variabilis

Experimental & Applied Acarology, 1990
Implants of Epon, inserted in Dermacentor variabilis (Say) through incisions in the cuticle, were encapsulated by hemocytes. We followed this process at intervals of 1,3,6, 12 and 24 h, and every 24 h thereafter up to 120 h. Degranulation of Type 1 granulocytes and coagulation of hemolymph were first seen at 1 h after implantation and were the earliest
Lewis B. Coons, William J. Lamoreaux, Lisa R. Eggenberger   +2 more
openaire   +3 more sources