Zika Mosquito Update

Zika has been getting a lot of attention in the media recently, as outbreaks of this mosquito-transmitted virus become evermore present in Central and South America. While much is still unknown about the Zika virus, one thing is for sure—limiting mosquito habitats and preventing mosquito bites are important precautions in mosquito-prone climates like Florida's.

The invasive mosquitoes Aedes aegypti (left) and Aedes albopictus (right) occur in the Americas, including Florida, and have been implicated in the transmission of Zika virus. Credit: J Newman, UF/IFAS/FMEL

Two species of mosquito found in Florida, Aedes aegypti and Aedes albopictus, can transmit Zika and other diseases as well, such as dengue and chikungunya. They can also transmit heartworm to dogs and cats.

The medical intricacies of Zika are better left to agencies like the Centers for Disease Control (CDC) and the Florida Department of Health. However, local UF/IFAS Extension offices can provide valuable information related to mosquito repellents and habitat reduction.

Reducing mosquito habitats

Aedes aegypti and Aedes albopictus are both "container mosquitoes," meaning that they lay their eggs above the water line in a container; they do not require standing water like other mosquitoes. Their eggs hatch when enough water collects in the container to reach the level of the eggs.

The best thing you can do is to scout your landscape frequently for any containers that might collect water and be sure they're empty. It's important to do this weekly, as water levels in containers can change from week to week depending on rainfall and irrigation. Types of containers that can collect enough water for mosquitoes include: wheelbarrows, potted plant saucers, used tires, gutters, buckets, cans, bottles, bird baths, rain barrels, and even bromeliad plants and bamboo that has recently been cut. For most of these, checking and emptying water once a week should prevent mosquitoes from reproducing in your landscape.

For bird baths, be sure to change the water weekly, scrubbing the basin in order to remove any eggs that might have been laid. Rain barrels should a very fine mesh over the tops, and tight connections where the gutter connects to the rain barrel. Mosquito "dunks" or "donuts" can also be used in rain barrels; these are safe and effective because the bacteria in these products, Bacillus thuringiensis israelensi (Bti), is only toxic to mosquito larvae and blackflies. Be sure to clean your gutters weekly as well to prevent them from becoming yet another mosquito breeding ground.

Bromeliads can also collect enough water in which mosquito eggs can hatch. You can either flush them once a week with a stream of water or sprinkle commercially available Bti "bits" in your plants.

Involving your whole neighborhood in mosquito prevention and clean-up events is also important. Keeping your yard free of mosquito breeding areas won't eliminate these annoying bloodsuckers if your neighbors aren't doing their part.

Personal protection from mosquitoes

Wearing protective clothing such as long pants and long-sleeved shirts is often uncomfortable in the Florida heat. Therefore, it is important to use an effective repellant and follow the proper application methods as written on the label.

When choosing a repellant, look for one with an EPA registration number. Always be sure to read the label carefully; while some repellants can be applied to clothing, others should never be applied to your clothes. Some will even melt plastics. Depending on the active ingredients, reapplication times differ among products.

Personal protection extends to your home as well. Be sure to check window and door screens regularly to make sure there are no holes where mosquitoes could be getting inside.

Taking these steps to reduce bites from mosquitos and any potential habitats is the best way to protect yourself and your family from mosquito-transmitted viruses. As always, your local county Extension office is a great resource for information on these precautions. Remember, questions about the human health effects of the Zika virus and other mosquito-transmitted viruses are best addressed by the CDC or Department of Health. The Florida Department of Health provides daily updates on the Zika cases documented in Florida (most recent update as of publication of this article). To date, all cases of Zika reported in Florida have been acquired from outside the state.

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