News

Marsh mosquitoes invade Palo Alto

Broken Baylands tidal gate aids insects' breeding; officials try to control the outbreak

Like the offspring in alien movies, mosquito eggs that have lain dormant in the Palo Alto Baylands mud for 10 to 15 years have been hatching en masse for the past three weeks -- thanks to a broken flood gate, according to Santa Clara County Vector Control officials.

The pesky critters are biting with a ferocity that officials said they haven't seen since the 1990s.

The Mayfield tidal gate, which is located east of U.S. Highway 101 and controls the flow of bay tidewater to the entire flood-control basin, has eroded. A gaping hole is allowing flooding of about 150 of the basin's 640 acres that are usually dry, said Russell Parman, Santa Clara County Vector Control acting district manager.

"We're in a rather unusual situation," he said, noting that the gates have successfully managed the water for 20 years.

The ebbing and flowing of salt water has activated the hatching cycle for the salt-marsh mosquitoes, which specialize in laying eggs above the water line at the edge of marshes. In just four days, an adult mosquito is on the wing.

So far, the mosquitoes have cycled through numerous "fly-offs" -- hatching, going through their larva and pupa stages and turning into full-grown biters.

These particular mosquitoes, also known as floodwater mosquitoes, are robust fliers, traveling up to 5 miles from their hatching site to feed on a blood meal and return to the marshlands to lay hundreds of eggs.

Most of the complaints from bitten humans have come from businesses along the Baylands and the Palo Alto Golf Course. But residents further inland at Seale and Greer parks said they have also experienced the voracious insects.

"My daughter has been doing soccer practice every day this week at Greer. All of the girls on her soccer team were covered in bites. I dropped her off this morning and got three bites just getting her bag out of the back of the car," Palo Alto resident Michelle Cale said.

On Monday she took her dog to the park and was immediately attacked.

"It's particularly bad on the grass. Even the ones with bug spray on them were bitten. They are not the West Nile-carrying type of mosquito, but they are especially bitey ones," Cale said.

Parman said the floodwater mosquito is not a West Nile carrier. It feeds on mammals rather than birds. But it will aggressively bite during the daytime as well as at night. The attack of the mosquitoes could last through October if breeding conditions remain in their favor, he said.

Since the discovery of the eroded gate, vector-control staff have been applying weekly ground treatments of larvicides.

The city's parks and golf-course workers have reduced irrigation to combat the problem. Parks crews are inspecting and fixing areas that have standing water, department officials said in an email to concerned residents.

The Santa Clara Valley Water District is working to fix the tidal gate.

Vector-control officials are looking into possibly applying aerial spray to the water over the affected portion of Baylands, but they must get permission from regulatory agencies such as the California Department of Fish and Game. Parman said the situation is somewhat complicated due to the several environmentally sensitive and endangered species that inhabit the Palo Alto Baylands.

A contractor is waiting for approval of a proposal. Aerial sprays, if used, would be restricted to the marshes, he said.

Parman said it's unlikely that any fogging would be done, as has been applied in Mountain View and Los Altos. Fogging is used when birds and mosquitoes in the area are infected with West Nile virus, he said.

Vector-control officials recommend the public wear mosquito repellant on top of clothes, rather than under clothing. The mosquitoes will readily bite through clothing as thick as denim jeans and thicker. Spraying or wiping a repellant containing DEET on top of clothing will significantly help.

Updates on the floodgate repairs will be available through the Santa Clara Valley Water District, at ValleyWater.org.

Comments

 +   Like this comment
Posted by Wondering?
a resident of Another Palo Alto neighborhood
on Aug 15, 2012 at 9:32 am

> thanks to a broken flood gate, according to
> Santa Clara County Vector Control officials.

So whose responsibility is it to inspect these floodgates on a timely basis? City of Palo Alto, or some other agency?



 +   Like this comment
Posted by Palo Verde Resident
a resident of Palo Verde
on Aug 15, 2012 at 9:59 am

Thanks for the information. We were wondering why the mosquitoes had recently been much more of a nuisance around here.


 +   Like this comment
Posted by Skeeter Bait
a resident of Greendell/Walnut Grove
on Aug 15, 2012 at 10:13 am

We are getting eaten alive near Middlefield and San Antonio, so it has already spread far and wide... I think the story should go into more depth about how this happend.


 +   Like this comment
Posted by dtakes
a resident of Palo Verde
on Aug 15, 2012 at 10:20 am

PLEASE spray!! I can't step outside without getting eaten up.


 +   Like this comment
Posted by anonymous
a resident of Duveneck/St. Francis
on Aug 15, 2012 at 10:28 am

I have these itchy bites on my leg - and this explains it. I have not had a problem in past with mosquitoes, fleas, etc. here. I hope steps are taken promptly to control this unusual problem.


 +   Like this comment
Posted by Mosquito Food
a resident of Duveneck/St. Francis
on Aug 15, 2012 at 10:41 am

I got 3 bites on my hand while walking the dog. What surprised me was being bitten during the day. I get bites periodically when I walk at dusk, but this was mid morning. They itch like hell and made my fingers swell.


 +   Like this comment
Posted by Bill
a resident of Another Palo Alto neighborhood
on Aug 15, 2012 at 10:52 am

It's great that we're paying a parcel tax for mosquito control, isn't it?


 +   Like this comment
Posted by Big Govt
a resident of Green Acres
on Aug 15, 2012 at 10:53 am

Mosquito abatement districts have been underfunded since the 80's.

We saved a lot of money for 3 decades before anyone noticed.

Get some spray.


 +   Like this comment
Posted by Peacemaker
a resident of Palo Alto High School
on Aug 15, 2012 at 10:55 am

Mosquitos carry Lyme disease....period.


 +   Like this comment
Posted by Don
a resident of Menlo Park
on Aug 15, 2012 at 10:57 am

Spray, Baby, spray!


 +   Like this comment
Posted by Mike
a resident of Meadow Park
on Aug 15, 2012 at 11:04 am

Lots of these mosquitoes biting yesterday afternoon on the Moffett Field golf course.


 +   Like this comment
Posted by Lucinda Abbott
a resident of University South
on Aug 15, 2012 at 11:10 am

According to the CDC:
"There is no credible evidence that Lyme disease can be transmitted through air, food, water, or from the bites of mosquitoes, flies, fleas, or lice."
Web Link


 +   Like this comment
Posted by Noel
a resident of Crescent Park
on Aug 15, 2012 at 11:11 am

Attn Peacemaker,

According to the Center for Disease Control, "There is no credible evidence that Lyme disease can be transmitted through air, food, water, or from the bites of mosquitoes, flies, fleas, or lice." There are Lyme carrying ticks in parts of CA near the Bay Area so you should always check yourself after hiking. But no worries about Lyme from mosquitoes!


 +   Like this comment
Posted by Doc
a resident of Leland Manor/Garland Drive
on Aug 15, 2012 at 11:16 am

Peacemaker,
Mosquitoes don't carry Lyme disease--ticks do.


 +   Like this comment
Posted by Chris S
a resident of Barron Park
on Aug 15, 2012 at 11:18 am

Thanks for the article. On a recent walk with my dog at dusk I must have had 10 bites. I was concerned that the mosquitos were following me from Minnesota, where I grew up. Once the problem with the flood gate is corrected, the mosquitos will disappear and I can go back to enjoying my bug-free walks.


 +   Like this comment
Posted by M Wolf
a resident of Midtown
on Aug 15, 2012 at 11:33 am

We should not be so hasty to turn to spraying, insecticides can harm and kill other wildlife and vegetation. Read "Silent Spring".
Effects of the mosquito larvicide GB-1111 on bird eggs.
Web Link


 +   Like this comment
Posted by JerryL
a resident of Adobe-Meadows
on Aug 15, 2012 at 11:41 am

Please spray. Spray over my house, even.
Spray as often as you can!


 +   Like this comment
Posted by pbisis
a resident of Palo Verde
on Aug 15, 2012 at 12:14 pm

I am outdoors all the time at the Baylands and in my garden, and I strongly oppose spraying when there is no evidence these mosquitos are carrying any disease. A nuisance, sure, but apply your own insecticide rather subjecting everyone and everything to spraying.


 +   Like this comment
Posted by Hmmm
a resident of East Palo Alto
on Aug 15, 2012 at 12:56 pm

We have them here, too. It's tiresome to read all of these Palo Alto-centric articles as if mosquitoes recognize city or county lines and only stay within certain boundaries!

We found one in our closed up car - after 2 of us were bitten. We've curtailed baylands walks due to the swarms.


 +   Like this comment
Posted by MzMiranda
a resident of Menlo Park
on Aug 15, 2012 at 12:59 pm

We're getting hit here in the Allied Arts area near the Palo Alto Shopping Center.


 +   Like this comment
Posted by Charlie
a resident of JLS Middle School
on Aug 15, 2012 at 1:51 pm

I took a walk at Mitchell Park, and got 4-5 bites in less than 2 minutes. I proceeded to run around flailing my arms until I got back to my friend's house.


 +   Like this comment
Posted by Bill
a resident of Another Palo Alto neighborhood
on Aug 15, 2012 at 2:04 pm

> Mosquito Districts underfunded ..

Maybe .. maybe not. With over $4B to spend this year, it's hard to understand where the County is spending all that money?

Santa Clara County board of supervisors to vote on $4.1 billion budget:
Web Link

Wonder if Liz Kniss knows what she has been voting on all these years?


 +   Like this comment
Posted by Big Govt
a resident of Green Acres
on Aug 15, 2012 at 2:07 pm

"> Mosquito Districts underfunded .. Maybe .. maybe not. "

Whoa, don't over-commit there, sailor.


 +   Like this comment
Posted by Palo Parent
a resident of Greenmeadow
on Aug 15, 2012 at 2:13 pm

The "Slow News Day" bar has reached a new low.


 +   Like this comment
Posted by Barb
a resident of Leland Manor/Garland Drive
on Aug 15, 2012 at 2:52 pm

DO NOT SPRAY, it causes cancer. If they are bothering you, eat alot of garlic! I kid you not, the smell then emanates from your pores and they stay away. In contrast, if you eat alot of sugar regularly in your diet, they seem to know that as well, and you will be attacked!.


 +   Like this comment
Posted by Buzz
a resident of Barron Park
on Aug 15, 2012 at 3:38 pm

As someone who has spent a significant amount of time in Alaska, all I can do is smile and nod at the local's reaction to this.


 +   Like this comment
Posted by Skeeter
a resident of Charleston Gardens
on Aug 15, 2012 at 3:54 pm

Only females will ruthlessly bore into you and suck your blood without any consideration for you at all. I'm talking about mosquitoes of course ;).


 +   Like this comment
Posted by Annie
a resident of Midtown
on Aug 15, 2012 at 4:40 pm

They've hit Hoover Park.


 +   Like this comment
Posted by wow
a resident of Old Palo Alto
on Aug 15, 2012 at 7:38 pm

Seriously? spray chemicals that do God-knows-what to all life in the area just to avoid a handful of bites from some mosquitoes? Boo hoo


 +   Like this comment
Posted by Mosquito Food
a resident of Duveneck/St. Francis
on Aug 15, 2012 at 8:18 pm

We've been spraying pesticides on our food, and doing mosquito abatement for a long time. It's not like the effects aren't well understood. It would be an ivory tower elitist that cries for organic certifications of a swamp.


 +   Like this comment
Posted by hurts
a resident of Community Center
on Aug 15, 2012 at 8:21 pm

I got three bites just yesterday by standing outside, the biting sites are swelling liike buns.


 +   Like this comment
Posted by Laura
a resident of Duveneck/St. Francis
on Aug 15, 2012 at 8:53 pm

Thank you for the explanation. We live near Duveneck and have been attacked even during the day which we have found baffling until I read your article.


 +   Like this comment
Posted by Davis
a resident of Midtown
on Aug 15, 2012 at 9:49 pm


They had better fix any and all flood control things before winter if we do get an El Nino. No excuses!


 +   Like this comment
Posted by it itches
a resident of Palo Verde
on Aug 15, 2012 at 10:02 pm

Do these mosquitoes tend to hit lower down? Thought those were flea bites on my ankles, even though I don't have pets.


 +   Like this comment
Posted by lots of leg bits
a resident of JLS Middle School
on Aug 15, 2012 at 11:57 pm

it itches,
We had the same experience!! Bites on the ankles and calves, which I thought at first were flea bites. It's probably because the landscaping watering is down there...

Lyme disease bacteria have been found in mosquito saliva and system, but doesn't survive and transmit as disease as far as anyone knows, i.e., mosquitoes are not Lyme vectors even though they have been found to be carrying live spirochetes.

Refer to research papers at the bottom of this well-written blog post
Web Link


 +   Like this comment
Posted by Allergic to the Suckers
a resident of South of Midtown
on Aug 16, 2012 at 2:08 am

Hey, pbisis and Barb, if you don't want to spray, can I send my mosquitoes to your house instead? I got a bite about three days ago *inside my house* — and yes, we have screens on all windows and doors. (I saw the bugger fly in front of my computer screen immediately afterward, and I think I managed to swat it.)

I smell so good to these guys that they'll find me even when no one else gets bit, and then I have to take extra antihistamine at night for days afterward in order to be able to sleep through the itching. I'm sure I'm not the only one around here with a mosquito allergy.

So, I hope the spraying of the marshlands for these guys takes place soon and often. (And Barb, I love garlic and eat a lot of it anyway. From what I've read, its effect as an insect repellent is unfortunately just an old wives' tale.)


 +   Like this comment
Posted by Bill Wohler
a resident of Menlo Park
on Aug 16, 2012 at 7:27 am

DEET will melt synthetics. Use permethrin on clothing.


 +   Like this comment
Posted by Utopia
a resident of Another Palo Alto neighborhood
on Aug 16, 2012 at 9:27 am

Trouble in paradise. Time to write a cranky letter to the Daily Post ...


 +   Like this comment
Posted by me, too
a resident of Palo Verde
on Aug 16, 2012 at 9:41 am

Ditto on the low-flying mosquitoes. I got bit on the foot and for the first time have taken an antihistimine in addition to applying a surface cream. Itchyyyyy!


 +   Like this comment
Posted by Hmmm
a resident of East Palo Alto
on Aug 16, 2012 at 10:47 am

Yes they are low flying, low biting. We had a chance to really observe them in action late afternoon yesterday. Reminded me how good mosquito abatement has been as we haven't had to use any mosquito deterrent on ourselves in years. I've seen them this week in grassy areas at Stanford, too.


 +   Like this comment
Posted by Effective Advocacy is More productive than whining
a resident of Another Palo Alto neighborhood
on Aug 16, 2012 at 12:09 pm

Do something productive if you are going to take time to write. Write a POLITE letter to Santa Clara County Vector Control and Santa Clara Valley Water District requesting prioritization of this repair. Clearly, there was some maintenance oversight. Support the city's effort to get resources applied to solving this problem.

Don't whine in a forum that no one with any decision-making authority reads. This is a democracy. Your work as a citizen is more productive if you write to the elected and appointed representatives who are making decisions.

Be an effective and reponsible citizen. Stop whining. Proactive problem-solving is more grown-up behavior than finger pointing and kvetching.


 +   Like this comment
Posted by Bill
a resident of Another Palo Alto neighborhood
on Aug 16, 2012 at 12:23 pm

> Write a POLITE letter

Writing "POLITE" letters achieves nothing.

The Daily Post ran an article this morning claiming the the fix to the flood gate is awaiting approvals from two agencies outside of County control.


 +   Like this comment
Posted by Buster
a resident of Midtown
on Aug 16, 2012 at 12:36 pm

El Carmelo elementary school on Loma Verde is horrible. They over water the grass and it's practically unusable because of the mosquitoes.

I can confirm they bite through clothes. Please wear underwear, I learned that one the hard way.


 +   Like this comment
Posted by skeeter fodder
a resident of Midtown
on Aug 16, 2012 at 12:57 pm

"to lay 100's of eggs"? try MILLIONS! one female mosquito can lay 1500 - 3000 eggs over her lifetime...how many female mosquitoes do you think there are? if there were only 1000 that could mean 3,000,000 eggs!






 +   Like this comment
Posted by student
a resident of Palo Alto High School
on Aug 16, 2012 at 6:54 pm

This is getting ridiculous!! Kids are getting bitten everywhere. I myself have 10 bites! And my mother got two on her eyes!!! Palo Alto NEEDS to do something.


 +   Like this comment
Posted by ann
a resident of Another Palo Alto neighborhood
on Aug 16, 2012 at 7:49 pm

they are now at Foothill College... it's spreading fast... are they looking for standing water?

can the paper interview the Vector control and show them this commentary strip.


 +   Like this comment
Posted by jb
a resident of Leland Manor/Garland Drive
on Aug 16, 2012 at 8:23 pm

They've gotten my husband. What we need is bats. Lots of bats.


 +   Like this comment
Posted by Michelle
a resident of Duveneck/St. Francis
on Aug 16, 2012 at 8:31 pm

If you are interested in what the Santa Clara Valley Water District says about the repair, this is the link to the story on its website: Web Link

They plan to make the repair "prior to the arrival of winter storms."


 +   Like this comment
Posted by Outside Observer
a resident of another community
on Aug 16, 2012 at 9:03 pm

Well, at least they don't carry malaria...... yet


 +   Like this comment
Posted by Local
a resident of Another Palo Alto neighborhood
on Aug 16, 2012 at 10:39 pm

I know they don't carry malaria, but what about similar diseases? I have had a tick-borne disease called babesiosis that I'm told is "malaria-like". People have died from getting transfusions and transplants from babesia infected blood. I have been treated and as far as I know I am not infectious, but I also am not allowed to ever donate blood again. Lots of small mammals carry this disease. You can contract and not know you have it until immune compromised, when it can be deadly. Looking for the same reassurance as above that mosquitoes can't transmit it.


 +   Like this comment
Posted by Hmmm
a resident of East Palo Alto
on Aug 17, 2012 at 10:37 am

Local - as informed as many are here, why would your rely on what we'd tell you about babesiosis? You'd have better luck w/a medical website or better yet - a doctor well-versed in tick-borne diseases. That in itself can be a trial, since there are controversial aspects of identifying & treating them. But if I were in your shoes, I'd research if on my own & then call the doc who treated me for babesiosis for the final word.


 +   Like this comment
Posted by CrescentPark neighbor
a resident of Crescent Park
on Aug 17, 2012 at 3:35 pm

They're all over my neighborhood too. I can't believe the number of bites we've gotten and how many I've killed. My daughter's soccer team got eaten alive at JLS too.


 +   Like this comment
Posted by Local
a resident of Another Palo Alto neighborhood
on Aug 18, 2012 at 12:00 pm

Hmmm,
Well, in answer to your question, sometimes people who know a lot about an issue answer a question posted online and provide very helpful links I haven't been able to find on my own. It isn't all people expressing opinions when they know nothing and have nothing constructive to add.

Medical doctors are not entomologists. I don't even get a consistent answer from medical sources about why I can't donate blood or tissue because of having had this disease even though the test is now negative.

I have read that the rate of infection by this disease among small mammals in the Bay Area is far higher than the rate infected by Lyme disease. Again, it's a "malaria-like" disease - what does that mean? Can mosquitoes transmit it?


 +   Like this comment
Posted by Old Hand
a resident of Old Palo Alto
on Aug 18, 2012 at 7:21 pm

Benydryl in a tube in my car and in my pocket while dog walking helps a lot - use it fast and the bite sites don't get big and fade in a day or two.

So..... two local agencies squabbling over how and when to fix a very serious problem while several towns' residents pay a very itchy price.... Shades of the San Francisquito Creek Fiasco.

I remember the malathion helo night flights -without lights years ago during the fruit fly outbreak. Spraying for mosquitos? It's best as spot application and getting the word out for all to get rid of any standing water everywhere.

Time for us to check for standing water on our properties and be ready to vote out the incumbants in November who allow these fiascos year... after year... after year.


 +   Like this comment
Posted by Call!
a resident of Old Palo Alto
on Aug 19, 2012 at 7:54 am

Flood their phone lines!! I've called the mayors office, city councils offices, and the vector control office several times today. Speak up and let them know that they are accountable for this. No more high pay and benefits!! They work for us!


 +   Like this comment
Posted by number
a resident of College Terrace
on Aug 19, 2012 at 8:16 am

can you tell me the number?


 +   Like this comment
Posted by Stop the itch
a resident of Greenmeadow
on Aug 19, 2012 at 10:24 am

Hot water (not boiling of course) or very cold water on a bite will stop the itching. Also Calamine lotion or Witch hazel.
Hot water really works. And yes, spray them!


 +   Like this comment
Posted by Call!
a resident of Old Palo Alto
on Aug 19, 2012 at 1:14 pm

Here are the numbers! Call and voice your displeasure! And remember this during voting time!

PA Mayor's office: (650) 380-8003 yiaway.yeh@cityofpaloalto.org
Council members:
Web Link
click on the individual members for their contact numbers

Santa Clara Vector Control:
1580 Berger Drive San Jose, CA 95112
(408) 918-4770


 +   Like this comment
Posted by Emily G
a resident of Duveneck/St. Francis
on Aug 19, 2012 at 4:08 pm

I play with my kids outside all day and they have been getting bites the size of dimes all over their bodies! It's like being in the forest! Thank you for telling us what is going on!!! PLEASE TAKE CARE OF THIS!


 +   Like this comment
Posted by mom
a resident of Another Palo Alto neighborhood
on Aug 20, 2012 at 12:05 am

Panther Camp/Tiger Camp at the middle schools this week -- are they adjusting for the swarms of biting insects?


 +   Like this comment
Posted by daniel o.
a resident of another community
on Aug 20, 2012 at 2:55 pm

These mosquitoes have made it to Golden Gate Park in San Francisco. Got bit 3 times today. Thanks a lot, Palo Alto!


 +   Like this comment
Posted by Ex-employee
a resident of another community
on Aug 20, 2012 at 6:50 pm

A little more info here:Web Link

Daniel o,
Can you blame the mosquitoes? You can hear them talking amongst themselves "Palo Altans taste bitter, go north to SF. They're much sweeter tasting."


 +   Like this comment
Posted by Staying Indoors
a resident of Downtown North
on Aug 21, 2012 at 9:49 am

So, Moonlight Run anyone? Maybe they can get DEET as a sponsor?


 +   Like this comment
Posted by NASA's Curiosity Rover
a resident of another community
on Aug 21, 2012 at 10:38 am

These mosquitoes have stung me 3 times already. My circuits are itchy.


 +   Like this comment
Posted by Wha?
a resident of Old Palo Alto
on Aug 21, 2012 at 2:31 pm

Has someone already posted this link from the San Mateo Co. district?
Web Link

Good basic information.


 +   Like this comment
Posted by Palo Alto Resident
a resident of Palo Verde School
on Aug 24, 2012 at 7:25 pm

I had been aware that the mosquitoes were much more vicious than usual, but up until now I didn't know why. Thank you for the update!


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