Photo Courtesy of GLACVCD

Where Mosquitoes Lay Eggs

Everything residents learned last year about West Nile virus and mosquitoes will be put to the test again this year, warned the Greater Los Angeles County Vector Control District (GLACVCD).

“The threat is real and cannot be underestimated. We are concerned that we may see more virus activity in 2015,” says Levy Sun, the district’s public information officer, as GLACVCD officials partner with officials from the Mosquito & Vector Control Association of California (MVCAC) to announce West Nile Virus and Mosquito & Vector Control Awareness Week, April 19 to April 25.

“Despite the drought, the warm weather and neglected water sources, such as swimming pools and flowerpot saucers, have provided perfect conditions for mosquitoes to thrive,” Sun said.

Last year, West Nile virus affected more than 800 people in California. There were 218 infection cases (including seven fatalities) reported in Los Angeles County, of which 60 were from the San Fernando Valley, according to the county Department of Public Health.

 In addition, several new invasive mosquito species were detected in Los Angeles County last year. More recently, an infected mosquito sample was discovered in Sylmar on March 18, “which is extremely early,” Sun said.

He said officials have seen “consistent positive activity” of infected mosquitos in San Fernando. “There were two positives in 2013, and last year had one positive.  And, last year, there was also one for Sylmar in August.”

Pacoima has not shown any recent positive activity for West Nile virus, Sun said. But he also pointed out that infected mosquitos “are everywhere” thanks to a combination of environmental factors and artificial sources like birdbaths and buckets that have standing water in them.

“West Nile virus is endemic throughout Southern California,” Sun said.

Valley “hot spots” for positive infected mosquito samples are often found include Canoga Park, Encino, North Hills, Northridge, Reseda and Sherman Oaks West Hills and Woodland Hills, the PIO said.

These mosquitoes are very difficult to control, and can transmit tropical diseases such as chikungunya, dengue, and yellow fever viruses. Because they lay tiny eggs in outdoor containers that hold water, yard cleanup is critical.

GLACVCD encourages residents to take the following safety precautions to protect against mosquito-borne diseases:

•Eliminate or manage all sources of standing water to discourage mosquito breeding every week. The work residents do now will make a big difference.

•If you are outdoors when mosquitoes are biting, wear long pants and long-sleeved shirts and use an insect repellent containing EPA-registered active ingredients such as DEET, Picaridin, IR3535, and Oil of lemon eucalyptus (PMD). Always apply according to label instructions.

•Make sure doors and windows have tight-fitting screens. Repair or replace screens that have tears or holes.

Contact the district at 562-944-9656 or visit if there is a significant problem or potential mosquito breeding source where you live or work.