Tick Sampling at Beaver Creek

Ticks are a commonly feared insect for the fact that they can carry diseases such as Lyme disease. Researchers Dr Maarten J. Voordouw, and others from the University of Saskatchewan and University of Regina conducted research about ticks at Beaver Creek Conservation Area. Their research included documenting different environmental factors to try to determine which areas ticks thrive in the most.

The Study Method and Technique

An American dog tick found in the Meewasin Valley

On June 26th, 2020, the group of researchers from the University of Saskatchewan and the University of Regina went sampling for ticks at Beaver Creek Conservation Area. The day was sunny and due to the park closure the trails were devoid of visitors. To standard way to capture ticks is the dragging technique, which involves pulling a white flag attached to a dowel over the vegetation. Ticks are sit-and-wait predators that climb up the vegetation and wait with outstretched legs to grapple onto a passing host. The moving flag simulates a host and the dark-coloured ticks are easy to spot against the white background.

What’s the Purpose of the Study?

The point of the study is to look for the blacklegged tick (Ixodes scapularis), which can transmit Lyme disease. However, as this tick species is not very common in Saskatchewan, trying to find it is like looking for a needle in a haystack. In contrast, the researchers had no problems finding the American dog tick (Dermacentor variabilis), which is by far the most common tick species in Saskatchewan. More than 95% of all tick bites in the province of Saskatchewan involve this tick species, which is not competent to transmit Lyme disease. In the USA, American dog ticks are known to transmit Rocky Mountain spotted fever and tularemia, but previous research has shown that the risk of these tick-borne diseases in Saskatchewan is low (for reasons that are not entirely understood).

The Results

The researchers dragged the flags for a total distance of 2 km. The protocol requires the measurement of GPS coordinates every 25 meters as well as measurements on leaf litter depth, soil humidity, and canopy cover. After completing the 2 km transect, more than 60 American dog ticks had been collected and placed in vials filled with 100% ethanol. Storing the ticks in this way prevents the degradation of DNA and allows the ticks to be tested for micro-organisms in the future.

This work is part of a long-term tick pan-Canadian sampling effort to determine the risk of exposure to blacklegged ticks and Lyme disease, which varies greatly across Canada. Over the last 30 years, the blacklegged tick has invaded and established itself in Ontario, Quebec, the Maritime Provinces, and Manitoba. In contrast, self-reproducing populations of blacklegged ticks have not yet been detected in Saskatchewan or Alberta. One possible explanation is that the dry prairie habitat throughout much of southern Saskatchewan is not suitable for blacklegged ticks, which are found in more forested areas and are very sensitive to desiccation. For this reason, the risk of Lyme disease in Saskatchewan and Alberta is much lower compared to other Canadian provinces. However, there have been locally acquired cases of Lyme disease in Saskatchewan.

How Else do we Get Exposed to Ticks?

If blacklegged ticks are not established in Saskatchewan, what explains these locally acquired cases? The answer is believed to be migratory birds. During the spring, migratory birds are estimated to drop off millions of blacklegged ticks in Canada. Some of these ticks are infected with Lyme disease and they can survive in the environment and bite another unlucky host. So, while the risk of Lyme disease in Saskatchewan is low, it is important to remember that there is still a risk. One more reason for the researchers to keep monitoring the tick situation in Saskatchewan.

Conclusion

The University of Saskatchewan’s Tick Surveillance program

Although the risk for being infected with Lyme disease from ticks in Saskatchewan and the Meewasin Valley are quite low, it is still important to know how to identify and add to the research done on them.

If you find a tick on yourself or your pet, you can learn how to identify it, remove it, and submit for research on this Government of Canada page. The University of Saskatchewan also has a tick surveillance program, which you can contribute to by simply taking a photo. Learn more about on their webpage.

Most of this article was written by: Dr Maarten J. Voordouw, assistant professor in the Department of Veterinary Microbiology at the University of Saskatchewan