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Tick Surveillance, Water Year 2022-2023

Tick Collections from parks, 2022-2023 Season (November 2022 through April 2023)

Laboratory staff continued spring surveillance for nymphal Ixodes pacificus (Western black-legged ticks) in April. Nymphal ticks are collected by flagging with a 1-meter square white sheet of flannel attached to a wooden dowel, in leaf litter areas or on rocks and fallen logs. Ixodes pacificus ticks will be tested for the presence of Borrelia burgdorferi (the causative agent of Lyme disease), as well as Borrelia miyamotoi (the agent of hard-tick relapsing fever) and Anaplasma phagocytophilum (the agent of granulocytic anaplasmosis).


Parks and neighborhoods surveyed in April include Edgewood Park in Redwood City, Portola Valley Ranch community of Portola Valley, Wunderlich Park in Woodside and Eaton Park in San Carlos. Additionally, the front and back yards of residences in Hillsborough, Woodside and Pacifica were flagged for nymphal ticks as a follow-up to a residential tick study conducted in the winter.

May contain: plant, vegetation, tree, land, nature, outdoors, woodland, tree trunk, wilderness, grove, art, collage, field, and grassland

Tick Collections from parks and neighborhoods, 2022-2023 Season (November 2022 through April 2023)

Park/NeighborhoodNearest City/TownNumber of Ix. pacificusNumber of Ix. pacificus nymphs
Edgewood County ParkRedwood City11655
Hidden Canyon ParkBelmont270
San Pedro Valley ParkPacifica196
Mori PointPacifica0
Memorial ParkPescadero39
Mills Canyon ParkBurlingame18
Milagra RidgePacifica17
Frontierland ParkPacifica245
Pescadero MarshPescadero300
Burleigh H. Murray RanchHalf Moon Bay394
North HillsboroughHillsborough263
Portola RedwoodsLa Honda383
Portola Valley RanchPortola Valley409126
Sweeney RidgeSan Bruno29
Wunderlich ParkWoodside 45
Eaton ParkSan Carlos60

Page last reviewed May 5, 2023

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