Monday, April 27, 2009

The Wood Tick

The male wood tick shown above was collected at Churn Creek (about 60km south of Williams Lake) in April of 2009. I managed to spot this tick at the top of a blade of grass immediately beside the trail upon which I was walking.

The wood tick, also called a sage tick, sheep tick, cattle tick or paralysis tick, unlike the winter tick, needs more than one host to complete its' life cycle. The stage that humans tend to pick up in the spring is the adult. It has already lived on two hosts (small mammals) at earlier stages in its' life cycle.

These ticks are common in the grasslands of British Columbia during April and May. Upon detecting carbon dioxide, vibrations or shadows, they climb to the top of blades of grass hoping to catch a ride on their next host. When they do find a host they slowly work their way to the groin, armpits or scalp, making sure not to bend any hairs suddenly which would make the host aware of their presence. Males, such as the one above, are on the host only to mate, and often in their scramble to find a female, they bend a hair making their presence known.

Females, once in a suitable location will settle down to feed. They bite, usually painlessly, and then secrete a glue-like substance around their mouthparts to hold them firmly to the host. This glue, along with some inflammation that may arise around the mouthparts, might make it seem that they are burrowing into the skin. Rest assured, ticks cannot do this. After a few days of feeding the ticks will drop off of the host to lay eggs on the ground.

The main concern with these ticks, in the Cariboo-Chilcotin is a slight risk of tick paralysis. Just what causes this is still uncertain, but people and animals suffering this condition will begin to stagger and lose muscular control. If the tick causing the problem is not removed, this will lead to death. Once removed, however, symptoms resolve in a little as 20 minutes.

These ticks do not carry Lyme disease. Lyme disease is carried by another tick entirely (genus Ixodes) of which, the particular species associated with transmitting Lyme disease to humans, is only found in the southern regions of the province--usually in cool dark forests. No documented case of Lyme disease has been recorded in the Cariboo-Chilcotin.

To remove a wood tick, grasp it firmly around the head region with tweezers and gently but firmly pull back. The tick will pull loose in about 15-30 seconds. Do not use gasoline, matches or any chemical on the tick as this may cause the tick to regurgitate into the wound and increase the risk of spreading infection.

For more information about ticks in the Cariboo-Chilcotin, click here.

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