Southern California with it’s majestic coastline, perfect almost 75 degree year round weather and summers where residents party outdoors leaving windows wide open is no more. Summer 2020 in Southern California brought many challenges, but the latest threat to the California dream…. the Aedes mosquito.Southern California residents generally weren’t bitten by mosquitoes….until now.

Don’t get us wrong, Southern California has always had the native Culex mosquito, but unlike the Culex mosquito, which prefers to feed on birds and therefore aren’t a nuisance to people, the Aedes mosquito prefers people. What’s more, the Culex mosquito will land and feed slowly, making them easier to swat away if you’re unlucky enough to fall victim. On the other hand, these Aedes mosquitos take many, quick bites leaving you with more itches, even if there’s only one mosquito. They also have been coined “ankle biters” because they tend to bite below the knee where they are less likely to be noticed until it is too late. What’s worse is the Aedes mosquito tends to be active during the daytime, when more people are out whereas the Culex mosquito tends to be active during the evening hours. 

Disease Threat

These mosquitos are more than just a threat to your afternoon jog or BBQ. While Culex mosquitoes have been known to carry diseases like Zika, they don’t normally bite humans meaning they didn’t play a huge role in transmission. However, the Aedes mosquitoes do bite people, meaning as their population grows, so could the transmission of the diseases they carry such as Zika, Yellow Fever and Dengue Fever.How do we get rid of them?Natural predators of the Aedes and Culex mosquitoes include bats, birds, fish, frogs, dragonflies and spiders.  But Los Angeles’s very own vector control is having trouble controlling them.Culex mosquitoes lay all of their eggs in one water source. Therefore, to get rid of them, all Vector control has to do is go to a location and scoop them out then drain that water source.Like the Culex, the Aedes lay their eggs in water. However, they only lay a handful of eggs per source and prefer smaller areas like bottle caps, crinkles in tarps and even the rim of a planter. The result is the eggs are harder to find and are less likely to be scooped or drained. And it gets worse, because Aedes eggs are resistant. They can be laid in dried out areas and lay dormant until water comes. 

How’d they get here and where do they come from?

A shipment of tires in the mid-1980s, is believed to have introduced the invasive Aedes mosquitoes to the Southeastern U.S. However, California had managed to stay clear of these invaders until 2001, when they were found in several counties and it was determined that these mosquitoes had been introduced by a shipment of ornamental “Lucky Bamboo” plants from Taiwan.What does this mean for the ecosystem?Although studies have shown that in lab conditions, the Aedes mosquito is the supreme competitor compared to the Culex mosquito, as of now, there’s little concern over the Aedes mosquito replacing the Culex in the California ecosystem. This has to do with “niches” – a specific environment or use of a resource. Both mosquitos have niches that overlap; they both lay their eggs in water and feed on birds. However, the niches are different enough for there not to be competition over resources; Culex mosquitoes feed at night while Aedes feed during the day and Aedes mosquitos can always feed on people if there aren’t enough birds. Additionally, around Los Angeles, there are enough people, birds and water sources through pools, fountains and plants that there is little threat of limited supply. This is because although there is some overlap, both fill different niches – a specific environment or use of a resource. Therefore, even though they both lay their eggs in water and bite birds, there is enough supply around Los Angeles so that there is little threat of major competition. The Aedes isn’t expected to replace the Culex mosquitoes, just join them.That being said, ecological relationships in nature are often so complex and intertwined that there may be a butterfly effect, like what happened in the case of Asian carps in the Great Lakes, so VECTOR wants to control the emerging Aedes population as much as possible. They encourage checking your area for water every few days, placing lids on rain barrels and performing a #tipandtoss of any stagnant water to help control the population. In doing so, hopefully our days enjoying the SoCal sun will stay itch free. 

Tell us, were you bitten by the Aedes mosquito this summer? Have you noticed any tips or tricks that are helping stop their spread? Please comment below, together we can protect the California dream.