Mosquito Prevention
After Heavy Rainfall and Flooding

Heavy rain and flooding can lead to increased mosquito production. With more water comes more mosquitoes and a higher risk of mosquito-borne disease. Early prevention can reduce mosquito numbers as the weather gets warmer.

Here are some tips to help minimize mosquito production around your home:

  • Clear debris from drainage ditches to allow water flow.
  • Use a sump pump to remove standing water that may have accumulated under your home.
  • Maintain swimming pools and spas.
  • Remove tarps, trash, containers, tin cans, jars, buckets, etc.
  • Recycle or dispose of old tires.
  • Clean rain gutters.
  • Dump water from items stored outside including kiddie pools, wheelbarrows, bird baths and plant saucers.
  • Properly screen or seal rainwater harvesting containers.
  • Click here for our "Common Backyard Mosquito Sources" checklist.

For more information or to report mosquito issues visit

What’s TICKing in the Lab?
This year’s tick season is in full swing. With the heavy rains over the past few months, the adult ticks have been hiding out and staying dry, waiting for the sun to shine and their hosts to walk by!

The District lab staff take every opportunity to conduct tick surveillance on public trails during the dry days, and it is clear that the rain has not washed the ticks away. Adult Ixodes pacificus are abundant in both Marin and Sonoma counties, and on February 22 District staff found the first Ixodes pacificus nymphs of the season. Each year, the timing of the tick stages varies slightly, depending on several factors including temperature and precipitation.

The District staff conduct tick surveillance as often as possible during the winter months so they can provide the public with the most up to date information about the risk of tick bites. The ticks that the District collects will be tested for two bacteria: Borrelia burgdorferi (the causative agent of Lyme disease), and Borrelia miyamotoi (which can cause a tick-borne relapsing fever-type disease).

Over the past 10 years, the average minimum infection rate of B. burgdorferi in adult ticks in Marin and Sonoma counties was 2.0%, while the minimum infection rate in nymphs was 4.3%. For B. miyamotoi , it was 2.5% in adults and 0.7% in nymphs.
Save the Date
May 18 11 a.m. - 3 p.m.
Open House
Don’t miss this fun, free, educational event for the whole family. Games, prizes, hands-on displays, live insects, free lunch and much more!!

The event will be held at the District Headquarters in Cotati, 595 Helman Lane, from 11 a.m. to 3 p.m.

Also, make sure your child enters the Backyard Bugs Contest for a chance to win some “buggy” prizes! Don't forget to like our Facebook page for updates regarding the Open House and the Backyard Bugs Contest!

Marin/Sonoma Mosquito and Vector Control District
595 Helman Lane, Cotati Ca 94931
707-285-2200 |