Aerial spraying for mosquitoes slated for Feb. 10


The Santa Clara County Vector Control District (SCCVCD) is planning a helicopter assault on winter salt-marsh mosquito in the Palo Alto marsh areas on Wednesday, Feb. 10, the district announced Friday.

Weather permitting, the aerial spraying is scheduled to start at 7:30 a.m. and may continue in the afternoon, according to a press release. If needed, the treatment may be extended to the morning of Thursday, Feb. 11.

The areas being treated include the ITT marshland and the Palo Alto flood basin ==I (Click here to view the map of the area being sprayed)==

The helicopter may make low-altitude passes over trails around the treatment area, so residents

are advised to avoid the area being sprayed. Vector Control District (VCD) staff and signs will be posted at different locations around the treatment area to notify visitors about the scheduled treatment.

According to the VCD, approximately 725 acres will be treated with water-based formulations of environmentally safe products, including methoprene, an insect growth regulator and Bacillus thuringiensis var. israelensis (Bti), a natural bacteria that kills the larvea when consumed.

"These products are mosquito-specific and short-lived in the environment: they effectively control the immature (aquatic stage) mosquitoes, but are not harmful to birds, fish, other insects, wildlife, or humans," according to the press release.

The mosquito — Aedes squamiger — lays its eggs in the moist soil in late spring and early summer. The eggs can lay dormant for years, even after repeated flooding, according to the VCD. High tides and seasonal rains, coupled with short days and cooler winter temperatures, cause the eggs to hatch as early as November, according to VCD officials.

The mosquitoes can bite humans and other mammals viciously during the day, officials said. They can fly over 15 miles from its breeding grounds to feed.

The aerial treatment is intended to minimize the number of mosquitoes and reduce the risk of mosquito bites to residents in the surrounding communities. According to officials, the mosquito fly-off can affect residents from the north coastal areas of the county to as far south as the southernmost part of San Jose and east to Milpitas.

Residents are encouraged to report mosquito-breeding sources, and to take preventive measures like wearing long-sleeved shirts and long pants and applying mosquito repellent when outdoors.

For more information, visit or call 408-918-4770.

For free assistance on mosquito control, call 408-918-4770 or fill out a service request online at or use the SCCvector app, downloadable at

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8 people like this
Posted by midtown greer
a resident of Midtown
on Feb 8, 2016 at 1:03 pm

This is useful warning. Thank you.

22 people like this
Posted by Netter than FOGGING people.
a resident of another community
on Feb 8, 2016 at 3:00 pm

Sounds better than "fogging" neighborhoods occupied by humans with a pesticide that kills or harms most every living thing

1 person likes this
Posted by musical
a resident of Palo Verde
on Feb 8, 2016 at 5:30 pm

I'd be impressed if DHS allowed spraying on Thursday morning.

19 people like this
Posted by Angela E
a resident of Menlo Park
on Feb 8, 2016 at 8:45 pm

Do not be fooled! The products vector control plans to spray on Wed and possibly Thursday are U.S. EPA registered pesticides. If you click on the MSDS sheets on the home page of Santa Clara County Vector Control, you will see that the products to be used for this efforts are pesticides. The article above says that vector control calls them "environmentally safe", but this is misleading and inaccurate. These are pesticides, pure and simple. Shame on vector control for misleading the public. Even the links to the MSDS sheets are partially hidden on their homepage...I had to click on a partial link to find them.

19 people like this
Posted by KJ
a resident of Greenmeadow
on Feb 8, 2016 at 8:59 pm

According to NPIC (jointly operated by Oregon State and US EPA):
"Methoprene is moderately toxic to some fish (rainbow trout), and highly toxic to others. In three studies on bluegill sunfish, the results were different in each case, ranging from moderate to very high toxicity. Methoprene can accumulate in fish tissues. It is moderately toxic to crustaceans such as shrimp, lobsters and crayfish, and very highly toxic to freshwater invertebrates."

These pesticides may not be that dangerous to humans, but it sounds like they mess up the food chain. On the East Coast, states are now restricting the use of Methoprene to protect lobster and fish populations.

Do we really need to kill these mosquitos?

16 people like this
Posted by Parent
a resident of another community
on Feb 8, 2016 at 10:13 pm

Why are they spraying during the day and when children are in school? They should coordinate with the school districts to ensure least possible exposure to children.

6 people like this
Posted by @AC
a resident of Meadow Park
on Feb 8, 2016 at 10:13 pm

It is not a bad idea to spray given the potential spread of Zika virus to this area. But I guess for Zika carrying mosquitoes, Bay may not be a prime breeding place.

16 people like this
Posted by Midtown resident
a resident of Midtown
on Feb 9, 2016 at 9:02 am

The spraying is poorly timed to occur on a school day, especially given that schools are closed on Thursday and Friday this week. Multiple parents at our school are calling the office to ask for the spraying to be postponed.

Here is the number to call if you have concerns:
Office Location for Vector Control District (VCD):
Phone: (408) 918-4770 or (800) 675-1155

8 people like this
Posted by Midtown resident
a resident of Midtown
on Feb 9, 2016 at 9:10 am

Here are the links to the two labels, as posted on the Vector Control site:
Web Link
Web Link

14 people like this
Posted by parent
a resident of Midtown
on Feb 9, 2016 at 9:17 am

Seems to me that a school day is the perfect time to do this, since kids will be in school instead of visiting the Baylands. These sprays have a very limited range, so won't affect anyone on the other side of the freeway.

12 people like this
Posted by Midtown resident
a resident of Midtown
on Feb 9, 2016 at 12:47 pm

Seeing as how there are no classes in Palo Alto schools on both Thursday and Friday this week, a much more thoughtful option would have been to spray then.

13 people like this
Posted by Midtown resident
a resident of Midtown
on Feb 9, 2016 at 12:53 pm

And to clarify, when I called the Vector Control Office to point out this week's school closures, they said that they didn't coordinate with schools, and yes, it would be nice to coordinate for Thursday or Friday - and that they will do that next year. Parents from our school are calling to try to have them postpone this week as well. Better be safe than sorry.

17 people like this
Posted by Resident
a resident of Another Palo Alto neighborhood
on Feb 9, 2016 at 1:05 pm

Yes, if they don't do it on a school day then they do it on a day when families may be out having fun in the Baylands. Seems to me that they are stuck between the devil and the deep blue sea. You can please some of the people some of the time, but you can't please all the people all the time.wGaAv

6 people like this
Posted by Midtown resident
a resident of Midtown
on Feb 9, 2016 at 3:44 pm

Resident: I agree with you completely about not being able to please everyone. No matter what, this planned spraying will affect some people, and my point is that it would have been nice if Vector Control would have considered trying to reduce unnecessary exposure as much as possible. There will be signs posted at the Baylands to ask people to avoid the area, so no one should be there tomorrow and maybe even Thursday. In my opinion, people having fun at the Baylands on a day off is a bit different from children being at school. Yes, concerned parents may opt to keep their child indoors tomorrow by taking them out of school but families can also plan to visit the Baylands on other days. We're talking about hundreds of young students vs. maybe a dozen or two families. And we're talking about postponing the spraying by 2 days. We belong to both of those categories (have children in schools and enjoy biking in the Baylands). I'd gladly postpone our trip to the Baylands if it meant spraying on a day when children weren't at school.

13 people like this
Posted by parent
a resident of Midtown
on Feb 9, 2016 at 6:45 pm

Which school are you folks talking about? As far as I know, no public school is anywhere near the target zone. The county has announced that there is no risk along East Bayshore or anywhere west of Hwy 101.

5 people like this
Posted by Call the school
a resident of Midtown
on Feb 9, 2016 at 11:56 pm

For parents who are worried about the pesticides, maybe call your school and ask that they open the library and/or MP room over recess and lunchtime to give the kids the option to play in there? That would certainly be easier than holding off the spraying. I suppose it's too late now, though...

7 people like this
Posted by David
a resident of Barron Park
on Feb 10, 2016 at 12:04 pm

Scientists have already discovered mosquito populations that have developed tolerance to methoprene. We should not be using this chemical as a routine preventative maintenance--we should save this chemical to squash active outbreaks of mosquito-borne diseases. Have we not learned anything from our overuse of antibiotics?

Encouraging the populations of predators (such as bats and birds) is not only better for the environment but also more likely to work in the long term.

9 people like this
Posted by Sidney
a resident of Charleston Meadows
on Feb 17, 2016 at 12:53 pm

Prior to the spraying there were lots of frogs in the evenings. Immediately after and since no more frogs along the bay trail.

Web Link

7 people like this
Posted by Really Angry Now
a resident of Another Palo Alto neighborhood
on Feb 17, 2016 at 3:17 pm

Sidney, you are not the o lay one who has noticed the silence at Baylands. My daughter and her friends often walk there around sunset, and they say it is eerily quiet.

This is really distressing, because most people are aware that frogs and toads EAT MOSQUITOES!

Talk about cutting off your nose to spite your face. Now the balance of nature has been thrown off.....any bird or other animal that eats the dying,mweakened, or recently dead frogs will be poisoned, too.

Like this comment
Posted by Plane Speaker
a resident of Crescent Park
on Feb 17, 2016 at 5:31 pm

I was loud out there the night before last.

The problem with this let nature do its thing, which I generally subscribe to,
is that the frogs are down on the ground and in the water and the mosquitos
fly around in big swarms right on the footpaths out by the Baylands.

If you run out there at the wrong time in the wrong place you get mosquitos
in your nose and eyes and get bitten. It's no fun. Plus there are nasty
diseases these days that mosquitos carry.

So, I have to come down on the side of spraying .... but ....

It would be really nice if the people who do this kind of things send
unbiased people out to survey the number of mosquitos, frogs and
whatever other life we are thinking might be affected by the spraying
before and after the spraying to report on what the effect of the
spraying was and some expert opinions on whether it is useful or not.

Really the general answer to most of our city problems is openness
and transparency and community discussion. It doesn't solve all
problems, sometimes we get groups of people on a stampede over
something that most think is trivial (my example would be basement
dewatering) but in general the more informaiton and the more ideas
and knowledge the better.

Like this comment
Posted by Esther Crass
a resident of Embarcadero Oaks/Leland
on Aug 18, 2016 at 10:13 pm

I must say city staff has really taken a great effort in eliminating all the mosquitoes. The idea of driving Fogger trucks in every area would help to vanish mosquitoes. Mosquitoes hides in most of the place like flower pots, abandoned swimming pools, clogged roof, gutters, where the smoke of Fogger trucks won't reach out to kill mosquitoes. In this case City environment staff should take help To get rid of all the pests including rats, bedbugs, termites and mosquitoes by contacting Professional Pest Exterminator in Sacramento, Florida, NY or other areas around Or one may also take some help from Web Link

Sorry, but further commenting on this topic has been closed.

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