The days will become longer and longer as we head toward summer solstice on June 20. That means a greater number of people are enjoying our famed Central Coast hiking trails — and increased chances of coming across ticks and the diseases they can spread.
Like a scene out of a horror film, adult western black-legged ticks (Ixodes pacificus) dangle on the tips of grass and other low-lying vegetation in their ghastly host-seeking posture called “questing.” In this stance, they spread their two front clawed limbs wide open and wait patiently for hours, or even days, for unexciting creatures to brush by so they can dig their metallike mouth parts inside their host and gorge themselves on blood. In other words, they let their banquet come to them. Contrary to popular belief, ticks don’t jump or fly.
At least the adult ticks can easily be seen, unlike the nymph or juvenile life stage, when the tick is about the size of a poppy seed and difficult to spot. Juveniles usually do not climb grass or shrubs while host-seeking; instead, they lurk closer to the ground on top of leaf and log litter on the forest floor, a perfect location to attach to lizards. In fact, research has shown about 90 percent of hosts for tick nymphs are reptiles rather than small mammals or birds.
This turns out to be a blessing, and here’s why.
The western fence lizard (Sceloporus occidentalis) — also lovingly referred to as a blue-belly lizard — is one of most common reptiles found in California. As a kid, they were my favorite as they were relatively easy to catch. You could turn a blue-belly on its back and gently rub their stomach, and they would go to sleep — or at least pretend to. The males have distinctive iridescent patches of candy-metallic blue along their flanks.
More importantly, they have a certain protein in their blood that kills a corkscrew-shaped bacteria called Borrelia burgdorferi, which causes Lyme disease.
Cal Poly Professor Emily Taylor, director of the university’s Physiological Ecology of Reptiles Lab, told me the western fence lizard isn’t the only species to carry the protein. Locally, so do other species such as alligator lizards.
“They possess an immune protein in their blood that appears to kill the bacteria that causes Lyme disease,” Taylor said. “This condition is significant because of the juvenile stages of the major vector for the disease, the western black-legged tick, often feed on lizards. If the ticks are previously infected, then eating the lizard’s blood will kill all the bacteria, and they won’t be able to pass it on to the next host when they are adults.”
In other words, our local lizards appear to be cleansing affected juvenile ticks, providing all of us a service. This is probably the primary reason so few adult ticks carry the bacteria along the Central Coast and, consequently, why there is a relatively low infection rate in California.
Still, here are some tips to avoid ticks from San Luis Obispo County Public Health Services:
Regularly examine yourself for ticks, and remove ticks promptly. Frequent tick checks provide the best prevention against Lyme disease. Wear light-colored clothing so ticks can be seen more easily. Wear a long-sleeved shirt tucked into pants, with pants tucked into boots or socks. Apply a tick repellent to clothing. Products with permethrin kill ticks on contact and are applied to clothing only. Products with DEET repel ticks and can be applied to the skin.
Always follow directions on the container and be especially careful when applying to children.
Stay on trails and avoid contact with bushes or grasses alongside trails, where ticks are common. Examine ticks on pets. Discuss tick control for your pets with your veterinarian. Visit http://www.slocounty.ca.gov/PA.htm for other tick safety tips.
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