Tick Surveillance in San Mateo County, January 2007

Entomology Report January 2007, San Mateo County Mosquito Abatement District

In January, tick collections were made from Edgewood Park, (Redwood City), Huddart Park, (Woodside), Laurelwood Park (San Mateo), Water Dog Lake (Belmont), and Costanoa (Pescadero). So far, a total of 827 ticks from 5 parks were collected. Evidence of infection with Lyme disease spirochetes was detected for the first time in Edgewood Park (1 positive) and Laurelwood Park (3 positives).

The District was contacted from residents of Belmont (near Water Dog Lake) and Pacifica with concerns about ticks in their neighborhoods. In Pacifica, questing ticks can be found in the open spaces between homes. In Belmont, western black-legged ticks were found inside a home adjoining the open space around Water Dog Lake, presumably brought in by the family cat. These instances illustrate the need to watch out for ticks even if one does not engage in outdoor activities at this time of year.

Previous related entries:

Tick Surveillance in San Mateo County, December 2006, December 2006
San Mateo County: Lyme Disease Surveillance Winter/Spring 2005-06, June 2006
San Mateo County: Lyme Disease Surveillance Winter/Spring 2005-06, April 2006
San Mateo County: Lyme Disease Surveillance Winter/Spring 2005-06, March 2006
San Mateo County: Lyme Disease Surveillance 2006, February 2006
San Mateo County: Lyme Disease Surveillance 2006, January 2006
San Mateo County: Lyme Disease Surveillance, November/December 2005
San Mateo County: Lyme Disease Surveillance, October 2005
San Mateo County: Lyme Disease Surveillance, January 2005

San Mateo County: Results of the Efficacy of Suspend on Density of Ticks Along a Recreational Trail

Entomology Report January 2007, San Mateo County Mosquito Abatement District

The insecticide Suspend (Deltamethrin) was evaluated for its ability to control Dermacentor ticks along a recreational trail in San Mateo County. Three days post treatment, showed a 98% decline in ticks. One week post treatment resulted in 100% control and after seven weeks the trail was still at a density of 0 ticks. This study showed that the material is very effective in controlling Dermacentors. In the future, another study will be performed to evaluate the efficacy of Suspend on Ixodes pacificus ticks.

Previous related entries:

San Mateo County: Trial Application of Suspend for Control of Ticks, May 2006
San Mateo County: Trial Application of Suspend for Control of Ticks, April 2006

San Mateo County: Results of the Evaluation of Trailside Mowing as a Tick Control Method, January 2007
San Mateo County: Effects of Mowing on Summer Tick Populations, June 2006

San Mateo County: Results of the Evaluation of Trailside Mowing as a Tick Control Method

Entomology Report January 2007, San Mateo County Mosquito Abatement District

This four-week study concluded that the mowing of grass on the sides of public recreation trails in San Mateo County was not an effective control method for Dermacentor ticks. In fact, although the sample size was relatively small, the density of Dermacentor variabilis ticks was found to have increased slightly on sites after they had been mowed. The density of Dermacentor occidentalis was not shown to have any significant relationship to mowing. While they do not transmit Lyme Disease, Dermacentor ticks remain a public health concern, as they are known to vector both Rocky Mountain Spotted Fever and Tularemia, and are very common ticks in San Mateo County.

Previous related entries:

San Mateo County: Effects of Mowing on Summer Tick Populations, June 2006

San Mateo County: Results of the Efficacy of Suspend on Density of Ticks Along a Recreational Trail, January 2007
San Mateo County: Trial Application of Suspend for Control of Ticks, May 2006
San Mateo County: Trial Application of Suspend for Control of Ticks, April 2006