Mosquito News & Notes

Hurricane Irma Triggered Dramatic Spike in Mosquito Populations, Study Finds

Mosquito populations in Miami-Dade County surged dramatically after Hurricane Irma, according to a study led by University of Miami health geographer Imelda Moise.

The 2017 storm caused widespread flooding, left nearly 900,000 without power and racked up $245 million in agricultural damage. But in the weeks following the storm, another problem emerged: a spike in disease- carrying mosquitoes.

“The warmer temperatures, high humidity and nutrient-rich floodwaters created ideal breeding conditions,” said Moise, an associate professor in the College of Arts and Sciences.

Moise and her team analyzed mosquito surveillance data from 2016 to 2018, using traps across 160 locations in Miami-Dade. They found mosquito counts were 7.3 and 8 times higher during a four-week period post-Irma than during the same period in 2016 and 2018, respectively.

Of the 32 species captured, Culex nigripalpus accounted for 70.4% of all mosquitoes trapped. The species is a major vector for diseases such as West Nile virus and Saint Louis encephalitis.

“Initially, it was believed that storms would wash away breeding grounds,” said Moise. “But populations rebounded within a week.”

The study also found mosquito abundance varied by trap type and time period, suggesting that hurricanes alter environments in ways that benefit some mosquito species.

Moise’s research highlights the need for greater public awareness and preparation in storm-prone regions. “Our findings serve as a call for vigilance in protecting against both nuisance mosquitoes and those that spread disease,” she said.

The study, which was published in Scientific Reports, is the first to examine the pre- and post- hurricane effects on mosquito populations in Miami-Dade.

Moise said she hopes to expand the research to explore potential links between hurricanes and disease outbreaks in other coastal cities. — Source: University of Miami

LA No. 1 on Orkin’s Top Mosquito Cities

According to Orkin’s 2025 Top 50 Mosquito Cities List, Los Angeles claimed the No. 1 spot for the fourth year in a row, with Detroit, Cleveland and Denver making major moves into the top 10.

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The annual list is based on the number of new residential mosquito treatments performed by Orkin from April 2024 to March 2025.

Chicago, New York, Atlanta and Detroit rounded out this year’s top five, with Detroit making its first-ever appearance in the top rankings. Cleveland and Denver also broke into the top 10 for the first time, signaling larger mosquito pressure in northern cities as temperatures climb, Orkin said.

California remains a stronghold for mosquito activity overall, with five cities in the Top 50: Los Angeles, San Francisco, Sacramento, San Diego and Fresno. With high temperatures and proximity to standing water, it’s no wonder mosquitoes are frequent residents of the West Coast state, Orkin said.

Here’s a look at the top 10 cities on Orkin’s 2025 list.

1.) Los Angeles

2.) Chicago (+1)

3.) New York (-1)

4.) Atlanta (+1)

5.) Detroit (+5)

6.) Houston

7.) Dallas (-3)

8.) Washington, D.C. (-1)

9.) Cleveland (+10)

10.) Denver (+6)

To view the entire Top 50 Mosquito Cities List visit bit.ly/479dFMN.

Mosquito Joe Earns EPA Gold-Level Recognition

Mosquito Joe, a Neighborly company, has received the U.S. Environmental Protection Agency’s (EPA) Pesticide Environmental Stewardship Program (PESP) Gold Level designation. Mosquito Joe said this recognition honors the company’s commitment to sustainable pest management practices that reduce pesticide risks to human health and the environment.

The voluntary PESP program promotes reduced pesticide use through innovative technologies and practices. Gold Level members are recognized for setting a high standard in environmental stewardship and pesticide risk reduction.

Mosquito Joe said it has reduced pesticide risk through its commitment to integrated pest management (IPM), particularly by focusing on outdoor treatments to reduce indoor pesticide exposure.

“We are incredibly honored to receive the EPA’s PESP Gold Level designation,” said Lou Schager, president of Mosquito Joe. “This recognition reflects our commitment to prioritizing the health and safety of our customers and communities.”