A mosquito invasion

Aggressively biting and stealthy mosquitoes thriving in Long Beach area, eggs can survive throughout the upcoming winter season.


Infographic by Sebastian Echeverry | Signal Tribune

The information shown above indicates size, nesting habits and identifiable traits of Aedes mosquitoes– an invasive species that primarily bites humans.

Barbecues, picnics and other outdoor activities can usually be considered staples of summertime. However, while participating in those activities, mosquito bites are rapidly becoming more frequent, and they could potentially lead to the outbreak of a virus Southern Californian officials have never dealt with.

In a Sept. 3 Nextdoor thread, many Signal Hill residents stated that they felt as if mosquitoes had invaded their yards. Residents wrote in their posts that they experienced numerous mosquitoes bites on their arms and legs throughout the day.

During a phone interview with the Signal Tribune last week, Kelly Middleton, director of community affairs for the Greater Los Angeles County Vector Control District (GLACVCD), said an invasive type of mosquito, one that primarily targets humans as its host, has found a home in the Long Beach area and other surrounding communities.

The Aedes aegypti and the Aedes albopictus mosquitoes are stealthy daytime biters that prefer humans over any other type of animal. They are approximately an eighth of an inch to a quarter of an inch in size and are identified by the black and white stripes found along their bodies.

Middleton said their aggressive nature may be the reason why residents feel more bites than usual.She also said GLACVCD has noticed an increase in service requests from residents.

Last year in August, Middleton said the GLACVCD recorded approximately 700 service requests to help identify mosquito-related problems around households. This year, there have been 1,400 service requests.

“People are complaining more about mosquito bites than they have prior,” Middleton said. “We are seeing a rise in the number of service requests that we receive from residents. It’s doubled from the same time last year.”

The GLACVCD reported on its website there is no confirmation of Aedes mosquitoes carrying and potentially transmitting Zika, dengue fever, yellow fever or chikungunya to people in Southern California at this time.

Middleton said the first time Aedes mosquitoes were found in Southern California was in 2001. The GLACVCD discovered its eggs inside of lucky brand bamboo shipments coming in through the Port of Los Angeles; however, Middleton said eggs were discovered at other ports throughout Southern California.

“We worked with other vector-control districts, the CDC and the folks down at the ports,” Middleton said. “We did inspections of all the cargo containers that were coming in. The CDC put an embargo on how the lucky bamboo could be shipped into California, and it literally changed the way that the product was brought into the states.”

Middleton said vector-control officials are not sure if the current Aedes spike is the population of eggs left over from the bamboo embargo, or if the mosquitoes are being shipped in again through a different method.

“Genetic testing shows that the ones we have now are virtually identical to the ones we had in 2001,” she said. “So, there was either continued importations, or it was a held-over population that was able to survive.”

If mosquitoes were to become infected with Zika, dengue fever, yellow fever or chikungunya, health officials are concerned Aedes mosquitoes already present in the area can easily transmit the diseases from person-to-person.

Officials with Long Beach Health and Human Services (LBHHS)– Judeth Luong, Emily Holman and Lamar Rush– told the Signal Tribune Tuesday during a phone interview that the Aedes mosquito population could survive throughout cooler months later in the year, prompting a year-round surveillance of the insect’s local population.

Courtesy GLACVCD
Map of Aedes mosquitoes found throughout California

Both LBHHS and GLACVCD officials are asking residents to help identify areas near their homes where mosquitoes can lay eggs, specifically in areas with still water.

Aedes mosquitoes mostly lay eggs in small containers that are holding water in yards– mostly in saucers under potted plants, vases that have flowers in them, buckets where plants are being rooted, old tires and water found in stems of plants.

They commonly lay their eggs around the edges of the containers or stems filled with water. Middleton said the eggs can remain alive in people’s yards for years. She suggested residents scrub out areas where water may be found in order to fully eliminate the eggs.

The GLACVCD uses Bacillus thuringiensis serotype israelensis bacterias, which produces toxins that are effective at killing various species of mosquitoes, to control adult-mosquito populations. However, Middleton said this process is not as effective compared to directly targeting mosquito eggs and larva.

Aedes mosquitoes do not fly too far from where they hatched, a pattern that could help in identifying where the other eggs could be found, according to Middleton.

Holman added that residents can call the LBHHS hotline to report mosquitoes near their homes. The number on its website is (562) 570-7907.

The CDC has identified LA County as one of the top-risk areas for the importation of diseases, such as dengue or Zika virus, because of the large population.

“We have 10 million people that travel south of the border and to Asia,” Middleton said. “They come back home, and if they have the virus in their system, and they get bitten by our local Aedes mosquitoes, then those mosquitoes could continue to spread it around. So, we could have an outbreak.”

During Tuesday’s joint interview with Luong and Holman, Rush explained that Brazil’s Zika virus outbreak in 2016 put global-health officials on alert, but he pointed out that while Brazil was experiencing its summer season, the United States was undergoing winter. However, he said cases of patients with Zika have been recently recorded in Mexico, which is on a similar seasonal pattern as the U.S.

“One infected mosquito could infect numerous people,” Middleton said, “and if the mosquito population is high, an outbreak can happen very quickly.”