CDC on mosquitoes and Zika—important correction
Thanks to Steven Zien at Organic Landscape for pointing out that the last issue of NewTerrain had an error:
“In your article, you talk about treating standing water with Bacillus thuringiensis (Bt). That is incorrect. That material only works on caterpillars and does nothing to mosquito larvae. If folks follow your instructions they will spend money needlessly and not prevent mosquitoes from developing. What they need to purchase and use is Bacillus thuringiensis israelensis (Bti). This is a different biological control product that manages mosquito larvae, black fly larva and fungus gnats.
“Out here in Sacramento, California the most commonly found products that contain Bti are Mosquito Dunks and Mosquito Bits from Summit.”
NewTerrain July 15, 206
Functional landscapes can also harbor undesirable species like mosquitos. Recently the Centers for Disease Control (CDC) recently released their Zika game plan, Interim CDC Recommendations for Zika Vector Control in the Continental United States. Because the Zika virus can be transmitted from an infected individual to a mosquito in the first week of infection that infected mosquito can then infect other people. Controlling mosquitos is vital and forms the base for Zika control.
The CDC says that the biology and behavior of the two mosquitos that transmit Zika, Aedes aegypti and Aedes albopictus, are different from the mosquitoes that transmit West Nile Virus (WNV). “Texas, Florida, and Hawaii are likely to be the US states with the highest risk of experiencing local transmission of Zika virus by mosquitoes, based on prior experience with similar viruses. However, additional states are assumed to be at some risk due to the presence of Aedes aegypti mosquitos,” says the CDC in their Interim Recommendations.
“Aedes albopictusmosquitoes are more widely distributed in the continental United States and Hawaii and have been proven competent vectors for Zika virus transmission,” says CDC.
CDC is recommending that states with Aedes aegypti mosquitoes should monitor Zika cases in returning travelers and “find and stop clusters of Zika before they become widespread.” Other states with Aedes albopictus should assume Zika transmission could happen and prepare.
States should rely on integrated vector management using cultural and chemical controls CDC recommends. Focus is on larva and adults.
The first line of defense is outdoors in the landscape, by eliminating standing water. Areas and items that hold water like corrugated downspout pipe, tires, buckets, planters, toys, pools, birdbaths, flowerpot saucers, wood pile tarps or trash containers provide habitat.
Water that can’t be dumped can be treated with Bacillus thuringiensis (Bt). Ensure cisterns are covered. Repair cracks or gaps in septic tanks and cover open vent or plumbing pipes with fine mosquito excluding mesh.
Mosquitoes rest in dark, humid areas like under patio furniture, or under the carport or garage. If you’re going to control adults, that’s where the focus should be.
Avoid mosquito contact by wearing long sleeved shirts and using insect repellents.
Be aware that in the event of a first transmission, states are advised to “Implement Targeted Control efforts around the case-patient’s home or building. Conduct intensified larval and adult mosquito control in a 150 yard radius (or other boundary as deemed appropriate) around the case patient home.”
If you’re getting questions, here are some resources and a link to the CDC map that tracks Zika in the US:
Updated CDC map on Zika cases (includes info. on how the virus was acquired)
Want to fight the bite? Mosquito prevention starts at home by Montgomery County, MD
Mosquito Control for Stormwater Facilities by NCSU Cooperative Extension
Proceedings of the Workshop on Stormwater Management and Mosquito Control by US EPA. While the focus is on West Nile Virus, there’s some good information if your primary business is stormwater features.
NewTerrain July 1, 2016.