Rains cause sharp rise in mosquitoes across Orange County

GARDEN GROVE, Calif. (KABC) -- A new problem has sprung in parts of Orange County following the end of the drought: West Nile Virus spread by mosquitoes.

Rain filling the wetlands created breeding grounds for the insects.

"The average nightly trap in March 2017 was 52 compared to the 21 mosquitoes per trap in the last five years combined," said Mary-Joy Coburn, with the Orange County Mosquito and Vector Control District.

The organization has kept a close eye on the skyrocketing numbers as they test mosquitoes for the West Nile virus and other infections.

"These mosquitoes are the Culex tarsalis, mosquitoes that are capable of transmitting West Nile virus and Saint Louis encephalitis," Coburn said.

The large numbers of the species have prompted vector control to drop granule larvicide via helicopter Wednesday, which has not been done since 2010.

The targeted areas include the Peters Canyon reservoir, Villa Park Dam, Santiago Pit and the Loma Pond.

"We want to target these mosquitoes right now in their aquatic life stages before they emerge as adults and start to bite people and transmit the diseases," Coburn said.

Vector control opted to use the helicopter because the areas are tough to reach by ground crews, but they assure the community that it is safe.

"(It) targets the mosquito larvae specifically and it's not harmful to people, pets or wildlife," Coburn said.

They plan to hit the same areas in three weeks.