Wood Ticks

family: ixodidae — hard ticks
species: dermacentor andersoni
common names: rocky mountain wood tick
antennae characters: no
specialties: hard ticks vector all major groups of pathogens
hosts: viruses, rickettesia, bacteria, protozoa, helminths
natural enemies: hosts 1 and 2 small mammals, 3 deer
cultural control methods: check for ticks on persons.
pesticides used: treated cotton is used by rodents in nests.
notes: 1 molt per bloodmeal, adult takes 1 bloodmeal for dev. of eggs, then dies, slow feeders- 3-5 days in two phases. transstadial transmission of pathogens. vectors Lymes disease.

Agriculture and Agri-Food Canada Insect Identification Sheet No. 36 1979 Rocky Mountain Wood Tick Dermacentor andersoni (Stiles) In Canada, the Rocky Mountain wood tick - a bloodsucking parasite of animals and humans - is found in British Columbia and Alberta. The greatest concentrations are to be found in areas such as river valleys where soil temperature and moisture conditions favour development of the pest.

Injury:

This tick species feeds on a different host during each stage of its development. In the larval and nymphal stages, it is usually found on mice, chipmunks, squirrels and other rodents; as an adult it is usually found on dogs, sheep, goats, cattle, deer and other large animals, and on humans. It causes paralysis in animals and humans, and is somearial the cause of death. It is also a carrier of the organism that causes Rocky Mountain spotted fever.

Life Cycle:

This species, which can overwinter in all stages of development, has a life cycle of 1 to 4 years depending on conditions. It is wingless and the body is covered with a leathery elastic cuticle that allows it to enlarge considerably during feeding. The mouth parts are highly specialized structures that enable it to pierce the host's skin and suck blood. The parasite has six legs in the larval stage and eight in the nymphal and adult phases. In the spring, the adults 'quest' for hosts by waiting on grass and shrubs. As a passing animal or human brushes against the vegetation, the ticks quickly transfer to the host and attach their mouth parts to the host's skin by means of a rapidly hardening cement and begin feeding. The mottled-gray adult males remain on the host. The females, reddish brown with a white shield near the front, feed for 7 days and reach the size of a swollen raisin; mated females then drop to the ground, lay several thousand eggs and die. In the transition from larvae to nymphs and nymphs to adults, both males and females finish feeding, leave their hosts and molt. Larval activity is greatest in July, while the nymphs may be active throughout the summer and in the following spring.

Control:

Eliminating this pest over large areas is not feasible. Clearing areas of brush, weeds and other low vegetation may help control the pest. Control of rodents and other small host animals could also help. For information on the control of this insect consult your provincial Department of Agriculture.