The Aedes aegypti, more commonly known as the yellow fever mosquito or ankle biter, was first recorded in Orange County in 2015.
Officials say the invasive pests have been found from Los Angeles to San Diego as well as in 29 Orange County cities.
Lora Young with the Orange County Mosquito and Vector Control district says the agency is getting many calls for mosquitoes now.
Each bug may only live about a week, but with days heating up, they're sticking around longer as a whole.
"We are seeing our mosquito season definitely lengthen all the way into October, November as we're getting warmer temperatures," Young said.
"They're also very aggressive day biters so that's why residents in the county are more impacted by them. They're feeling the biting pressure of them."
Luckily, so far, these ankle biters haven't spread disease in Orange County, but the potential to transmit Zika, dengue or chikungunya is there.
Young says keeping these bugs away is a shared responsibility and the best way is to not leave untreated water out. They only need a bottle cap full to breed.
"We need everybody to inspect their backyards weekly and talk to their neighbors. That's the only way we're going to reduce the numbers of these mosquitoes."