A local Outbreak of the Winter or Moose Tick, Dermacentor albipictus, Pack. (Ixodoidea) in Saskatchewan

Abstract

(1) D. albipictus, known as the winter or moose tick, is a common parasite of moose, elk and deer in the forests of northern Saskatchewan. As in the outbreak described in this paper, it may attack and cause serious losses among the cattle and horses of settlers which are permitted to graze in the haunts frequented by its native hosts. Deaths among the moose are frequently attributed to the ravages of the tick.(2) The eggs of D. albipictus are deposited in the ground by the engorged females, which continue to drop from the hosts throughout the winter until the beginning of May. The larvae emerge from the eggs during the late summer and probably remain dormant until such time as the period of drought passes and cooler weather arrives. Attachment to the host is achieved by the larvae in the autumn, and both the larval and nymphal moults are undertaken on one and the same host. During the summer months the hosts are free from its attacks.(3) Infestation of cattle and horses may be prevented by their maintenance in fenced, tick-free pastures or in barns from the end of September until the beginning of May. Animals that have become infested may be treated with an arsenical dip. Dipping, however, cannot be safely accomplished after September in northern Saskatchewan because of the risk of severe chills that may be contracted by treated animals consequent on the low prevailing temperatures of the autumn months.Tick-infested fields may be cleaned by being ploughed in the spring after all the ticks have dropped. The engorged females are buried, and even though the eggs may hatch, the larvae will find difficulty in reaching the surface in the autumn to attach themselves to a host.

The Biological Survey of Canada: A Personal History

“…In Canada, winter ticks have also been collected from a variety of other mammals including: mule deer, Odocoileus hemionus (Rafinesque) (Samuel et al 1981;Welch et al 1991;Wilkinson 1970), white-tailed deer, Odocoileus virginianus (Zimmermann) (Gregson 1956), woodland caribou, Rangifer tarandus caribou (Gmelin), reindeer, Rangifer tarandus tarandus (Linnaeus) (Welch et al 1990), plains buffalo or bison, Bison bison bison (Linnaeus), wood buffalo or bison, B. b. athabascae Rhoads and mountain sheep, Ovis canadensis Shaw. Among domestic animals, horses and cattle are occasionally severely infested (Bruce 1927;Cameron and Fulton 1927;Bishopp and Trembley 1945). Although many mammal species are likely suitable as hosts, the engorgement and reproductive success of female winter ticks are greatest when they are fed on moose .…”

“…Although many mammal species are likely suitable as hosts, the engorgement and reproductive success of female winter ticks are greatest when they are fed on moose . Winter ticks rarely bite people and bites usually occur when adult ticks transfer from wild or domestic hosts onto people (Cameron and Fulton 1927;Bequaert 1945;Bishopp and Trembley 1945).…”

“…Adult D. albipictus can be found on naturally infested hosts from December to May (Cameron and Fulton 1927;Addison et al 1979;Glines and Samuel 1984). Males precede females by 2-3 weeks and persist much longer, comprising the majority of adult ticks present on hosts in May (Addison and McLaughlin 1988;Drew and Samuel 1989).…”

“…Males precede females by 2-3 weeks and persist much longer, comprising the majority of adult ticks present on hosts in May (Addison and McLaughlin 1988;Drew and Samuel 1989). Mating occurs on the host shortly after female emergence (Cameron and Fulton 1927) and females must be mated in order to complete engorgement (Oliver 1974). Adult females begin to appear in late January, reaching peak abundance by late March and early April (Addison and McLaughlin 1988;Drew and Samuel 1989).…”

“…Painful swellings can occur at the site of D. albipictus bites (Cameron and Fulton 1927); however, because they bite humans infrequently, winter ticks have little potential to transfer pathogens directly to humans. Borrelia burgdorferi, the pathogen responsible for Lyme borreliosis, has been isolated from a small percentage of D. albipictus removed from white-tailed deer in B. burgdorferi-endemic regions of the United States of America .…”