Identifying Blacklegged (deer) Ticks

• What are blacklegged ticks?
• How do blacklegged ticks spread the infection?
• Where and when are blacklegged ticks found?
• What is a suitable blacklegged tick habitat?
• What should I do with blacklegged ticks that I find?
• For more information
• Lyme Disease - Environmental Health (Manitoba Health) Fact Sheet

What are blacklegged ticks?

Blacklegged ticks (Ixodes scapularis) exist in three active stages: larva, nymph and adult.  The life cycle of blacklegged ticks takes at least three years to complete and each active stage usually survives for up to one year.  Blood is required by the tick to move to the next stage. Unfed larvae and nymphs are light in colour and very difficult to see (Figure 1).

Unfed adult female blacklegged ticks are approximately 3 to 5 mm in length; and are red and brown in colour; while adult males are smaller than females and are uniformly brown in colour (Figure 1).  Adult blacklegged ticks are smaller than the more common American dog tick (often called wood tick).  American dog ticks have white markings on their backs while blacklegged ticks do not
(Figure 2).  American dog ticks usually do not transmit the Lyme disease bacteria.

Figure 1: Life stages of the blacklegged tick (1-larva, 2-nymph, 3-adult male, 4-adult female). Sizes presented in relation to underlying 10-cent coin. Photos reproduced with the permission of Robbin Lindsay, Public Health Agency of Canada. Click photo to enlarge.
Figure 2: Adult American dog (wood) ticks (bottom row) and blacklegged (deer) ticks (top row). Photos reproduced with the permission of Robbin Lindsay, Public Health Agency of Canada. Click photo to enlarge.
Figure 3: Image of adult female blacklegged tick at various stages of engorgement. Photos reproduced with the permission of Robbin Lindsay, Public Health Agency of Canada. Click photo to enlarge.
Figure 4: Image of blacklegged tick nymphs at various stages of engorgement. Photos reproduced with the permission of Robbin Lindsay, Public Health Agency of Canada. Click photo to enlarge.

^ top

How do blacklegged ticks spread the infection?

Blacklegged ticks can transmit the Lyme disease bacteria by biting an animal or a person.  However, not all blacklegged ticks are infected with the bacteria.  Also, infected ticks must be attached for 24 hours or more before the bacteria is transmitted.  Nymph and adult blacklegged ticks can transmit infection.

The Lyme disease bacteria circulates between blacklegged ticks and wild animals that can maintain an infection, such as mice, squirrels and some bird species.  People and domestic animals can be exposed to the Lyme disease bacteria when they are fed upon by an infected blacklegged tick.

^ top

Where and when are blacklegged ticks found?

Blacklegged ticks have been submitted from many locations in southern Manitoba and occasionally from more northern areas as part of the Blacklegged Tick and Lyme Disease Surveillance Program.  Tick submissions range from about 150 to 300 blacklegged ticks per year. 

Throughout southern Manitoba, there is a chance of being exposed to the Lyme disease bacteria through contact with infected blacklegged ticks transported by birds. However, there is a greater risk in areas where there is an established blacklegged tick population.  Surveillance efforts in recent years have found established blacklegged tick populations in Manitoba.  Manitobans are advised to take precautions against ticks when in suitable tick habitats.

Check the Manitoba Health website for the latest information on the locations of established tick populations in Manitoba and links to where blacklegged ticks have been found in other provinces or countries.

^ top

What is a suitable blacklegged tick habitat?

Blacklegged ticks survive best in locations that provide them with moist habitat.  Wooded or forested areas are very suitable because the trees provide shade and leaf litter for ground cover to protect active ticks.  These habitats also support populations of small mammals, birds and large mammals such as deer which provide the blood meal sources for the different tick life stages.  Adult blacklegged ticks are most active in the spring and fall and they remain active until the first permanent snowfall or when air temperatures are consistently below 4^oC.  Larvae and nymphs are most active in the spring and summer months. 

Blacklegged ticks cannot jump or fly. Instead, they seek hosts by climbing on vegetation such as grasses or shrubs and waiting for a host to rub against them.  When this occurs, they climb onto the host’s body and eventually attempt to attach and feed. 

Ticks may be brought into the home on clothing or pets. Most indoor environments are too dry for blacklegged ticks to survive for more than a few days.

^ top

What should I do with blacklegged ticks that I find?

• Manitobans can submit blacklegged ticks as part of the Blacklegged Tick and Lyme Disease Surveillance Program. Individuals are encouraged to submit ticks during the fall surveillance campaign.
• Ticks should be placed in a small crushproof bottle (ex: pill bottle) with a piece of slightly damp paper towel to help keep the tick alive.
• Firmly tape the lid shut.
• Seal the bottle in a plastic bag and then in a cardboard box labeled: Research Specimens  Fragile – Handle with Care and send to the following address:

  Dr. Terry Galloway, Department of Entomology
  Animal Science/ Entomology Building, Room 214
  Fort Garry Campus, University of Manitoba
  Winnipeg, MB R3T 2N2

• Include the following details: name, address and phone number, information about where, when and on whom (ex: person, dog) the tick was found, as well as any recent travel activity.
• Results of the testing will be provided once completed.

Submission forms

Submission Form [MS-Word]
Submission Form

^ top

For more information:

Talk to your health care provider, your local Public Health Unit or call Health Links-Info Santé in Winnipeg: 788-8200 toll-free (outside Winnipeg): 1-888-315-9257. 

^ top

 

 

 

 

For more information, please contact:
Public Health and Primary Health Care Manitoba Health 4th Floor - 300 Carlton St. Winnipeg Manitoba  R3B 3M9  CANADA Phone:  (204) 788-6737 Fax:       (204) 948-2040	Health Links-Info Santé 788-8200 or toll-free at 1- 888- 315-9257