Treeless Tropics, More Disease-Carrying Mosquitoes?

Deforestation doesn’t just strip the landscape. In tropical regions, it may also lead to more disease-carrying mosquitoes, University of Florida researchers say.

“Converting pristine tropical forests into areas for agriculture or other uses creates a habitat for the mosquitoes that transmit human diseases,” lead study author Nathan Burkett-Cadena said in a university news release. He’s an assistant professor of entomology.

The scientists don’t say why those mosquitoes might thrive without extensive tree coverage, but they note that deforested areas are warmer and drier than similar pristine forests.

For their report, the researchers analyzed 17 studies from around the world. They found a strong link between deforestation in tropical habitats and higher concentrations of mosquitoes that carry diseases transmittable to people.

Almost 57% of mosquito species in deforested areas were confirmed carriers of human disease, compared with about 28% of mosquito species in forested areas, the investigators said.

They also found that mosquito species capable of carrying multiple human diseases favored deforested habitats. These include Aedes aegypti mosquitoes, which transmit the dengue, West Nile, yellow fever and Zika viruses.

The last couple of decades have seen an increase in efforts looking into the association between deforestation and specific diseases,” said study co-author Dr. Amy Vittor.



The findings were published recently in the journal Basic and Applied Ecology.

My Take:
My home in South Florida is one of these areas. We have expanded west from the coast into the Everglades as our population blooms. Additionally, a series of hurricanes have devastated our tree canopy. In 2005 Hurricane Wilma wiped out 50% of our tree canopy. The figures are not yet in on Hurricane Irene this year but it cut a much wider swathe through the entire state.

Cases of all the mosquito borne diseases noted above have started to show up in South Florida. They are expected to eventually spread across much of the continental United States.

I am surprised that health officials have contained the Zita virus as well as they have. However, I still believe they are delaying the inevitable.

The Bottom Line:
We need to develop a global approach to all the damage we are causing to our environment. Denial is no longer an option. We argue about melting of the polar caps, rising sea levels and stronger hurricanes but changes in disease patterns are much more likely to end the human race. I’m just concerned that we won’t connect all the dots until it’s too late.