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Floods, Warm Temperatures Promote Mosquito Production

Web Admin Florida

Extensive rains, flooding and scattered debris that hold water can lead to mosquito development.

Hurricane Idalia
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Eva Buckner, an Extension specialist at University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Florida Medical Entomology Laboratory in Vero Beach, remains in close contact with many of Florida’s more than 65 mosquito control programs providing training, solutions and information on topics including mosquito insecticide resistance, mosquito-borne diseases, integrated mosquito management and more. She also educates the public on how to prevent mosquito bites.

Buckner offers the following facts and tips to help keep residents from getting bitten, eliminate mosquito production sites during flood recovery and dispel myths about mosquito-borne diseases.

Q: Can flooding promote mosquito population growth?

A: Yes. Flooding can cause mosquito eggs laid in the soil by floodwater mosquitoes during previous floods to hatch. This can result in very large populations of floodwater mosquitoes. Most of these mosquitoes are considered nuisance mosquitoes because they are primarily annoying biters that do not transmit any viruses to humans. Additionally, if floodwaters do not recede, standing water mosquitoes may start laying eggs on the standing waters.

Q: Do some of these mosquitoes carry viruses like Zika and West Nile?

A: In general, floodwater mosquitoes are just considered nuisance mosquitoes, except for Aedes aegypti, the yellow fever mosquito. This species can transmit chikungunya, Zika and dengue virus.

In Florida, this species can be found in some suburban and urban areas in the peninsular portion of the state. In areas with Aedes aegypti, increased rainfall may result in increased hatching of Aedes aegypti eggs from water-holding containers.

Also, some species of standing water mosquitoes can transmit West Nile virus, so steps should be taken to protect from mosquito bites.

Q: What steps can residents take to protect themselves from mosquito bites?

A: The most important tip to remember is to use Environmental Protection Agency (EPA)-registered insect repellents with one of the following active ingredients: DEET, picaridin, IR3535, oil of lemon eucalyptus (OLE), para-menthane-diol (PMD), or 2-undecanone. Wearing loose-fitting, long-sleeved shirts and pants can also help protect from mosquito bites.

Q: What steps can residents take to control mosquitoes around their homes?

 A: Dumping water from water-holding containers commonly found surrounding homes, such as pet dishes, vases, buckets, toys, flowerpot saucers, and cans is recommended for reducing mosquito production. You can help reduce your risk of diseases just by dumping or treating water-holding containers. Use granules, pellets, or dunks containing Bacillus thuringiensis subspecies israelensis (Bti) bacteria to kill immature mosquitoes in water-holding containers that cannot be drained easily like birdbaths or bromeliads. Bti-treated water is safe for animals to drink. Bti products can be purchased at hardware or box stores. For vast water sources, it is best to leave the source reduction and treatment to the mosquito control agencies. Contact your local mosquito control program to ask for treatment request. For more information, please see Mosquitoes and Their Control: Integrated Pest Management for Mosquito Reduction around Homes and Neighborhoods.