This summer, right after the 10th person died from West Nile virus in Dallas, the city decided to begin large-area spraying for mosquitoes using the relatively benign pesticide known as Duet.
Calls to expand the use of pesticides to combat mosquito-borne diseases such as West Nile virus fall into the usual trap that entangles short-term solutions to human problems with disregard to the environment. The immediate benefits look great; the long-term cost is not borne by those making today’s decisions.
A healthy coexistence of humans with other species in sustainable ecosystems will require more innovative solutions than a simple return to pesticides. Among mosquito-borne illnesses, malaria and dengue fever show lower frequency in response to wise human behavioral changes.
Biological control of mosquitoes through restoration of native predators in their breeding grounds offers a long-term solution to the spread of many mosquito-borne diseases. Recent studies show that West Nile virus is less prevalent in areas with a higher diversity of native birds. Even benign pesticides, like Duet, will select for resistant mosquitoes, while at the same time reducing the populations of insectivorous birds that are effective mosquito predators.
An exceptionally warm winter in Texas is thought to be responsible for the current outbreak of mosquitoes and the West Nile virus there, suggesting that we can expect more, similar events in response to the ongoing climate change that we are experiencing.
To combat infectious disease, we should rely on common sense and nature’s natural diversity.
Photo, taken on October 28, 2006, courtesy of Flickr.