Lone Star ticks are well-established across much of the United States, raising questions about their presence in California. While not considered endemic or widely established in the state, isolated instances and transient populations have been reported. This means they can occasionally be found in California, though they are not prevalent.
Understanding Their Presence in California
The Lone Star tick’s primary distribution covers the eastern, southeastern, and midwestern U.S. Their range has expanded northward and westward, influenced by factors like a warming climate and changes in land use creating suitable habitats. Increased white-tailed deer populations, a preferred host, also contribute to their spread. While a crowdsourced project documented encounters in six California counties, the California Department of Public Health states the Lone Star tick, known to transmit ehrlichiosis, is not widely found in the state.
Identifying Lone Star Ticks
Lone Star ticks have distinct physical characteristics across their life stages. Adult females have a single, silvery-white spot in the center of their reddish-brown back. Adult males display less prominent white streaks or spots along their body edges. Unfed adult females are about 1/8 inch long, expanding considerably when engorged with blood, and their oval bodies turn slate gray after feeding. Immature stages also have distinguishing features: larvae are six-legged and pinhead-sized, while nymphs are eight-legged and slightly larger, like a poppy seed.
Health Risks Associated with Lone Star Ticks
Lone Star ticks can transmit several pathogens causing various human illnesses. They are primarily associated with Alpha-gal syndrome, a unique food allergy. This condition occurs when a tick bite transfers an alpha-gal sugar molecule, triggering an immune response. Consuming red meat or other mammalian products like dairy or gelatin can then cause mild to severe allergic reactions. Beyond Alpha-gal syndrome, these ticks transmit other bacterial and viral diseases. These include Ehrlichiosis, causing fever, chills, headache, and muscle aches. Southern Tick-Associated Rash Illness (STARI), characterized by a “bull’s-eye” rash resembling Lyme disease, is another concern, often with fatigue, headache, and muscle pains. They are also linked to Heartland virus, Bourbon virus, and Tularemia.
Preventing Tick Bites
Protecting oneself from tick bites is important, regardless of the tick species. When outdoors, wearing appropriate clothing reduces exposure, including long-sleeved shirts, long pants, and tucking pant legs into socks or boots. Light-colored clothing makes ticks easier to spot. Using EPA-registered insect repellents on exposed skin is effective; those with DEET, picaridin, or IR3535 are recommended. Permethrin can treat clothing and outdoor gear for extended protection. Avoid tick-prone environments like wooded and brushy areas, tall grass, and leaf litter, sticking to cleared paths when hiking. After outdoor activities, perform a thorough tick check. Examine hidden body areas like behind the ears, armpits, groin, and belly button. Showering within two hours helps wash off unattached ticks. To eliminate ticks on clothing, tumble dry on high heat for at least 10 minutes.