During spring, the District sometimes gets reports of flying
insect swarms. These insects look a lot like mosquitoes, but are
actually a different type of insect: midges.
The good news is that these midges don’t bite, don’t carry any
diseases, and are harmless to humans. The bad news is that, as
many of you have already found out, they can be really annoying!
They’re often seen in large swarms, and may gather around outdoor
lights or on the sides of buildings.
The California Department of Public Health (CDPH) advises spring
break travelers vacationing in warmer climates to protect
themselves from mosquito bites and avoid unprotected sex in areas
with known transmission of the Zika virus.
“Spring break is the perfect time to have fun in the sun, but it
is important that people take precautions to prevent Zika,” said
CDPH Director and State Public Health Officer Dr. Karen Smith.
“Unfortunately, the mosquitoes that spread Zika enjoy warm
If you’re planning spring break travel, plan for mosquitoes!
Popular spring break destinations like Mexico and the Caribbean
are included in the CDC’s list of areas with active Zika virus
transmission, and may also be under travel advisories for other
mosquito-borne illnesses like chikunguna, dengue, and
malaria. A full list of travel advisories from the CDC is
available at https://wwwnc.cdc.gov/travel/notices.
Do wet or dry years create more mosquito problems? One
might immediately assume wet years because mosquitoes need water
to breed. On the other hand, droughts create pools and
puddles in water bodies like rivers and streams that would
otherwise be flowing too strongly for mosquitoes to
utilize. The reality is both weather patterns cause
different types of mosquito control challenges.
Some bird species are more likely to be affected by West Nile
virus than others. These six species are the most commonly found
infected in California, but any wild bird species can be reported
Tularemia, rabbit or deerfly fever, is a relatively rare
bacterial disease transmitted to humans and animals by the bite
of ticks. It is much less common that Lyme disease in California
and is primarily transmitted by the American
dog tick (Dermacentor variablis) and possibly by the
Pacific Coast tick (Dermacentor occidentalis).
The District laboratory is taking advantage of breaks in rainy
weather to collect ticks from parks and open space areas in San
Mateo County. Ticks are collected by dragging a tick
flag – a large white piece of flannel attached to a wooden rod –
over the vegetation alongside trails. The main target
species of tick is Ixodes pacificus, the western black-legged
tick, which vectors Lyme disease, Borrelia miyamotoi infection,
and anaplasmosis. The ticks collected will be tested for
the presence of bacteria that cause these diseases. The
Ixodes pacificus ticks are in
San Mateo County Mosquito and Vector Control District Awarded
District Transparency Certificate of Excellence
Burlingame, CA – 9 January 2017
In recognition of its outstanding efforts to promote transparency
and good governance, San Mateo County Mosquito and Vector Control
District has been awarded the District Transparency Certificate
of Excellence by the Special District Leadership Foundation
Today a resident brought in an insect she’d found on her live
Christmas tree. She was concerned that it might be a kissing bug, the insect vector
of Chagas disease.
Fortunately, the specimen was not a kissing bug. It was a western
conifer seed bug, a minor tree pest to conifers – like Christmas
trees! These bugs aren’t harmful to humans, and can be gently
relocated outside if found indoors.
If your holiday decorating plans include a live tree, prepare
yourself for the possibility of a few unwanted visitors.
No, we don’t mean your opinionated uncle – we’re talking about
bugs. Your live tree has spent several years growing outdoors on
a tree farm where it served as a home for all kinds
of insects, spiders, and other creepy-crawlies. Most of them
probably dropped off before your tree arrived at your home -
especially if it was shaken to remove loose needles or shipped
from far away - but a few may have hitched a ride
On November 1, Stanford researcher Dr. Jon Flanders gave District
staff an informative presentation on bats. Dr. Flanders is
currently conducting bat research at Jasper Ridge Biological
Preserve, in Portola Valley. He shared his knowledge of bats in
general, as well as the current findings of bat tracking in
Jasper Ridge. In collaboration, the District provided him with
mosquito monitoring data for the area that can be analyzed in
conjunction with the bat data.
As invasive Aedes aegypti and Aedes
albopictus mosquitoes increase their range in
California, the District is always on the lookout for these
species in San Mateo County. We always appreciate residents’ help
in watching for these invasive mosquitoes, but so far in 2016
(fortunately!) none have been found.