Mosquito populations could sharply rise after heavy monsoon rains

TUCSON, Ariz. (KOLD News 13) - Floods follow fires, and with all the rain lately, mosquitoes follow monsoon storms. An unusual amount of rain could lead to a big number of mosquitoes and the diseases they carry.

The Pima County Health Department traps, counts and identifies mosquitoes around the area and tests them for diseases. They said less than about 1,500 have gone under their microscope this year after trapping.

“It’s probably about 300-400 less than last year this time,” said Gregg Bustamante, an environmental health technician at PCHD.

The dry monsoon seasons and drought the last few years have had an impact on mosquitoes. Their breeding ground dried up.

“The last couple years, without having a lot of standing water, or much rain to speak of whatsoever, the adult mosquito populations were really, really low,” said Michael Riehle, from the department of entomology at the University of Arizona.

However, populations, while down, can spike quickly with ample breeding grounds, said Riehle. Females are the only ones that bite, and after their meal, they can lay eggs, which can turn into dozens and dozens of adults.

The process takes a little less than two weeks, from egg to adult. In the coming weeks, the area is likely to see an increase in mosquitoes.

“About 14 days after the rain, that’s probably when you’ll start seeing mosquitoes,” said Bustamante.

The issue with that, is the diseases they carry. If certain types of mosquitoes reproduce more, the more disease could spread.

“We might actually see a surge in West Nile cases,” said Riehle.

So far, cases of West Nile have been fairly low around the state. No cases, as of last week, have been reported in people or mosquitos in Pima County.

There are 13 probable and confirmed cases are reported in Maricopa County, according to the state health department. While Pinal County hasn’t reported any human cases of West Nile, they have found the disease in mosquitoes.

To help fight the bite, experts encourage using bug spray during dawn and dusk and wearing long sleeves and pants.

Also, they said to remove any standing water, even small amounts around pots of plants, to help reduce a potential mosquito boom.

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