The San Gabriel Valley saw no deaths from West Nile virus during the pandemic lockdown, and vector control officials say they are hoping to continue the trend by reminding residents to get rid of standing water on their properties to prevent the mosquitoes that transmit the illness, and others, from breeding.
The region generally sees several deaths from West Nile virus each year, San Gabriel Valley Mosquito & Vector Control District spokesman Levy Sun said.
“But in 2020, we didn’t see that at all. And we were really, really grateful for everyone’s participation in mosquito control. Because we always say mosquito control is a shared responsibility. And 2020, despite all the odds, proves that to be true.
The pandemic lockdown may have increased the public’s vigilance toward mosquitoes, he said.
“We have noticed people are a lot more aware about mosquitoes around their home than they were before the pandemic. And that’s a good sign, because they’re learning how to stay bite-free,” according to Sun. “That’s all of us: The public, mosquito control and public health achieving the impossible during an impossible time.”
The life cycles of the various varieties of mosquitos that call Southern California home are largely dependent on water. But despite an unusually dry winter, the region may soon be inundated with the disease-spreading pests without the public’s help, Sun said.
“Unfortunately, there will still be mosquitoes,” he said. “The prime driver of mosquito creation or mosquito production tends to be from private properties. We saw this in the last major drought in California. We saw that a lot of people were still using a lot of water around their homes, which resulted in a lot of stagnant water and small sources such as plant saucers and buckets.”
The dry weather could make matters worse, Sun added.
“During a season when we do have multiple rain events, we actually see that our underground storm drain systems get flushed out, which is great because the mosquitos during winter will hunker down in our underground storm drain,” he said. “But if the dry condition persists, there will actually be more mosquitoes in our city.”
Mosquito eggs can live for months, or even years, in dry conditions until conditions become wet enough for them to hatch, according to Sun.
“That’s the reason why they’ve been spreading so quickly through our cities,” he said. “These mosquitoes are not native. They primarily thrive near people because of our habits of changing our own environment to be conducive for stagnant water.”
“There has been research showing that the Aedes mosquito egg can survive even up to five years. So there’s a chance that these mosquitoes they’ll act like time capsules and they will hatch out when the conditions are right again for them,” Sun said.
Aedes mosquitos are capable of carrying Zika virus, dengue fever, yellow fever and chikungunya.
Very little water is required to hatch the tiny eggs, Sun added. “ A bottle cap of water is enough for these Aedes mosquitoes to be attracted to.”
Careful watering, avoiding stagnant water and use of native California plants, rather than more thirsty types, can go a long way in reducing the mosquito population, he said.
“We are optimistic that the trend that we’ve seen from 2020 will carry forward,” Sun said. “And we’re hoping that if we do get hit with a drought, people will still understand the need to conserve water and maybe even convert their yards to using California native plants.”
More information is available on the San Gabriel Valley Mosquito & Vector Control District website at sgvmosquito.org.