MENDOCINO CO., 6/30/26 — Tick season, most people figure, is a summer thing. In the oak woods around Hopland, scientists have spent the better part of 40 years showing that’s backward thinking. Here the tick that spreads Lyme disease is out all year — crawling up grass stems in the dead of winter — and the one most likely to make you sick is too small to notice.
The bugs are active year-round here, and the worst stretches don’t line up with beach weather. Adult western blacklegged ticks — Ixodes pacificus, the species that spreads the Lyme bacterium in the West — are most active on the north coast in the dead of winter, climbing grass stems along trail edges from about Halloween through spring. The nymphs — immature ticks that drive most human cases of Lyme — take over in spring and early summer.
This information comes largely from the University of California’s Hopland Research and Extension Center, more than 5,300 acres of oak woodland and grassland in southeastern Mendocino County. Scientists have dragged cloth flags through the center’s brush for decades to count ticks and test what they carry. It’s at Hopland that researchers documented the western blacklegged tick’s three-year march from egg to egg-laying adult, and where much of what California knows about its own Lyme risk was first measured.
Yet another downside of climate change
The newest Hopland research, published in May in the Journal of Medical Entomology, adds a wrinkle: the season is sliding. Analyzing more than two decades of the center’s nymph counts, researchers Francesca Rubino, Emily Pascoe and Zachary Barrand found that hot, dry springs push the nymphs to peak earlier the following year — roughly 3.4 days earlier for each additional hot, dry day the previous May. Their climate models project that peak tick activity will keep moving up the calendar as warming increases, and that the number of years with unusually dense nymph populations could rise sharply by the end of the century.
For anyone who hikes, gardens, cuts firewood or just sits on a log in Mendocino County, the practical takeaways from the research are blunt.
First, the ticks are everywhere there are woods. When UC and federal scientists sampled 78 dense-woodland sites across the county two decades ago, the western blacklegged tick turned up at every one.
Second, the small ones are the problem. A nymph is about the size of a poppy seed, and most people who get Lyme never remember a bite — only about 23 percent of California patients in one state review could recall the bite. Statewide, roughly 2 to 15 percent of nymphs carry Borrelia burgdorferi, the bacterium behind Lyme; among adult ticks it’s closer to 1 to 2 percent.
Third — and this is the part the official numbers get wrong — the human case count almost certainly understates the risk. From 2013 to 2019, California reported 904 confirmed Lyme cases, about 0.3 per 100,000 people a year, and more than 80 percent of them came from Northern California. Yet Mendocino, a county that Robert Lane — the UC Berkeley entomologist, now emeritus, who is California’s foremost authority on the tick — judged as endemic as the heavily infested northeast coast, rarely lands among the state’s top reporting counties. The likeliest explanation isn’t that the ticks here are clean. It’s that California isn’t considered a high-incidence Lyme state, and testing and physician awareness lag — so cases slip through uncounted.
It’s not just Lyme to worry about
Lyme is only part of the danger. The same western blacklegged tick can spread other sicknesses too. One is anaplasmosis, which is sometimes serious. Another is hard tick relapsing fever, which causes high fevers that keep coming back. Doctors didn’t confirm it could make people sick in the U.S. until 2013 — even though the germ had been living in ticks for decades. In a recent study, scientists checked ticks in seven Northern California counties. The germ behind that relapsing fever, Borrelia miyamotoi, showed up in more young ticks than the Lyme germ did.
A second, bigger tick adds another concern. The Pacific Coast tick — common in the county’s inland oak and chaparral, where Robert Lane’s crews once collected 220 of them — carries Rickettsia rickettsii subsp. californica, a spotted-fever germ confirmed to sicken people only in the past two decades. It leaves a black scab at the bite instead of a bullseye rash, and human cases stay rare: fewer than two dozen have been confirmed, all in California.
Praise the lizard king
There is one piece of good news, and it also came out of UC’s research. The nymphs’ favorite host by far is the western fence lizard — the gray lizard doing push-ups on every fence post and woodpile. More than 90 percent of nymphs in some woodlands feed on lizards, and a protein in lizard blood, UC Berkeley researchers found, kills the Lyme bacterium inside a feeding tick. Scientists point to that lizard effect as one reason California’s Lyme rates run far below the East Coast’s.
That’s the science. The defense is low-tech: tuck your pants into your socks, treat clothing with permethrin, stay in the center of trails, check yourself and your kids — scalp, behind the ears, waistband — and shower within a couple hours of coming in. And if you find one attached, don’t panic and get it off correctly.
How to remove a tick
Act fast. The California Department of Public Health says an infected western blacklegged tick generally has to stay attached at least 24 hours before it can pass the Lyme bacterium, so prompt removal often prevents infection. Don’t wait for a doctor’s appointment to pull it; the U.S. Centers for Disease Control and Prevention says to remove an attached tick as soon as you find it.
1. Grab it on the skin. Use clean, fine-tipped tweezers and grasp the tick as close to the skin’s surface as you can. No tweezers? Use regular tweezers or your fingers, shielded with a tissue or glove.
2. Pull straight out, slow and steady. Even pressure, straight away from the skin. Don’t twist or jerk — that can snap off the mouthparts. If a piece breaks off, try to lift it out with the tweezers; if it won’t come, leave it alone and clean the spot. The mouthparts on their own don’t transmit Lyme.
3. Dispose of it. Drop the live tick in alcohol, seal it in a container or bag, wrap it tightly in tape or flush it.
4. Clean up. Wash the bite and your hands with soap and water, rubbing alcohol or hand sanitizer.
Skip the folk remedies. Don’t use petroleum jelly, nail polish, a hot match or any other substance to “back the tick out.” The CDC warns those methods can make the tick force infected fluid into the wound.
Then watch for symptoms. See a doctor if you develop a rash — especially an expanding, target-shaped one — or fever, chills, aches or fatigue in the days and weeks after a bite, and tell them when and where you were bitten. Early Lyme is usually cured with antibiotics.
Want to know what bit you?
Save the tick in a small bag or in rubbing alcohol. The Lake County Vector Control District in Lakeport will identify ticks for free and in some cases test them for the Lyme bacterium. Mendocino County has no lab of its own, so its Public Health department directs residents to the Solano County and Sonoma County public health labs, which charge a fee. Sonoma County Public Health and the Marin County public health lab handle tick testing, also for a fee.
Another wife’s tale: do not use peppermint oil to get the tick off. The Lyme disease bacterium is not transmitted from the egg to nymph. It is picked up by the feeding nymph from an infected host.
Very interesting article. Had me reaching for old entomology and medical bacteriology textbooks.
Borrellia and Rickettsia are important genera. Too bad Mendocino doesn’t have a public health lab
Thanks for writing about Lyme disease. It’s more prevalent than breast cancer, and has been linked to degenerative diseases like MS. It’s much more serious than just arthritis. However, this part of the article should be revised: “3. Dispose of it. Drop the live tick in alcohol, seal it in a container or bag, wrap it tightly in tape or flush it.”
Do NOT dispose of a tick that bit you. Mail it straight to a laboratory for testing. IGeneX offers tick testing services, and now other labs do, too.
Why? If you get sick, the diagnostic tests available at public hospitals are FAULTY. They do not work. And the hospitals can’t even test human specimens for every tick borne diseases, just a few.
The existing diagnostic tests for hospital patients are flawed — drastically and intentionally in the case of Lyme disease. The private health insurance industry made sure of it. Please watch a documentary called “The Quiet Epidemic”. The film exposes the ways in which private insurance companies had meddled with the diagnostic criteria of Lyme disease several decades ago, in order to be able to deny health care to individuals who are suffering from persistent Lyme disease.
The systemic medical neglect of tick borne disease patients is NOT the hospital staff’s fault, in this case, but rather the fault of Congress for having little to no oversight of private health insurance companies massive and corrupt influence on the country’s healthcare paradigm.
Perhaps one reason this is undercounted is that among those of us who spend significant time in the woods and fields of Mendocino County, many of us are resigned to this. In my remote valley we all get bitten every year. Many times. Hundreds of times over the years. We pick ticks off of dogs nearly every day. We pick ticks off of ourselves. We know that ticky feeling when our skin crawls. We take precautions, but still we get ticks. We are probably pulling that tick off of us within minutes, but still. If there is Lyme, spotted fever or whatever – you’re going to be exposed out here. Hopefully our immune systems, getting massive training from so many bites, are up to the task. But hey, live/work in the woods of Mendocino County, you’re going to get tick bites and that’s just the reality.
I got a tick bite near Gualala a few years ago and discovered the skin pattern of Lyme disease. At the local clinic, the nurse confirmed my observation and I was given a common antibiotic. If you catch it early, you should be okay. I can’t imagine how the deer and other wildlife contend with it.
Thank you, Mendocino Voice, for another very pertinent, useful article that concerns us here in Mendocino County specifically. Keep up the good work.
There is a single-dose oral antibiotic more than 90% effective in preventing Lyme Disease if administered within 72 hours of the original bite.