Flooding from Hurricane Isaac will increase mosquito population

Johnny Morgan, Ring, Dennis R., Schowalter, Timothy D.  |  9/5/2012 1:17:36 AM

News Release Distributed 09/04/12

Floodwater left behind by Hurricane Isaac is providing the nearly perfect environment needed to increase the mosquito population, which could also increase the cases of West Nile virus.

More than 60 species of mosquitos inhabit the state, and water helps them reproduce, according to LSU AgCenter entomologist Dennis Ring.

“During drought conditions, mosquitoes are known to lay their eggs in places that will eventually hold water,” Ring said. “Once the water comes, they then have the condition needed for the eggs to hatch and the larvae to grow.”

Ring said if there are containers around that will hold water for more than a week, that’s long enough for the eggs to hatch.

Things that can be done around the home to reduce the mosquito population include:

– Remove containers that hold standing water, such as old tires and other debris.

– Empty flower pots and other yard and patio containers.

– Drain fountains, ornamental ponds and swimming pools no longer being properly maintained or treat them with Bt discs (a bacterial pathogen of mosquito larvae).

– Fill low-lying areas to avoid standing water.

– Provide drainage ditches to promote rapid runoff of rainwater.

Louisiana’s climate creates conditions that support the mosquito population year-round, said LSU AgCenter entomologist Tim Schowalter. “And while many are benign, some are carriers – or vectors – of several worrisome diseases.”

Throughout this summer West Nile virus cases have reached numbers not seen in recent years, and standing water seems to be the main reason, Schowalter said.

“Female mosquitoes require standing water to lay their eggs, and if we can deny this, there is a better chance of keeping their numbers low,” Schowalter said.

When standing water is available near homes, the mosquito has all that it needs to reproduce.

“She has to have a blood meal or she will die before laying her eggs,” Schowalter said. “But if humans or other animals are around and the standing water is available, the conditions are favorable for the increase in populations.”

It normally takes about two weeks for mosquitoes to go through their breeding cycle in standing water, and then they become the biting pests that are both feared and hated.

In addition to West Nile virus, several other mosquito-borne diseases found in Louisiana, include St. Louis encephalitis, eastern equine encephalitis and LaCrosse-California encephalitis.

Find more information about mosquitoes online at www.LSUAgCenter.com, then type mosquito in the search box.

Johnny Morgan

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