The War Against Mosquitoes


It’s summertime: we go outside for picnics, camping trips, or other outdoor activities, but almost everywhere we go, we’re always attacked by mosquitoes.

Here in my part of Colorado, the San Luis Valley, the mosquito invasion this year has taken full force. Lots of rain has left standing water everywhere, giving mosquitoes many places to lay their eggs and multiply.

Fortunately, we have defenders, organized here as the Alamosa Mosquito Control District, supported by a special tax collected within its 125-square-mile area.

The District was originally established in 1966 as a way of reducing the amount of nuisance mosquitoes in the area.

“If you were going outside your parents would have to wrap newspapers around your arms and legs,” says Sarah Cantu, the district manager. “Or you just wouldn’t go outside at all because the mosquitoes were so bad.”

In its war against mosquitoes, the District’s field operations break down into what Cantu describes as “surveillance, larvicide, and adulticide.”

The District’s field crews monitor standing water sites for mosquitoes, trapping and examining them in their laboratory. Then they kill mosquitoes with eco-friendly poisons targeted at larvae in the water or adults flying in the air.

This is an especially challenging year for the District: they typically only spray in areas where there is usually a lot of standing water, but now there are many places where water is reaching where it hasn’t fallen in years, causing dormant mosquito eggs to hatch.

“A mosquito will lay eggs in a place where she’s expecting water. It might not come, but those eggs can lay dormant for up to five to ten years,” says Cantu.

The amount of mosquitoes here has greatly reduced since the District was established, but its fight against mosquitoes is even more serious than before. There are many different species of mosquitoes in Colorado, and one of them can carry the West Nile virus that is now widespread in the United States. In its surveillance work, the District sometimes finds mosquitoes that are infected with the virus, so it needs to be vigilant.

Keeping a low profile but always on the offensive against billions of voracious enemies, the District is making summers much healthier and more comfortable in the San Luis Valley.