Mosquito control in a wet area

Asked April 4, 2016, 5:36 PM EDT

I have an area in my pasture that retains & runs a steady flow of water (grows cat tails & is swampy) once my neighbor begins to irrigate his land (I am downhill of his property). I was wondering what is the best way to manage the upcoming mosquito problem that is effective and safe for people & animals.

I also have a thistle problem to manage as well. Is there particular livestock (goats) that eat this noxious weed. What do you suggest for a safe herbicide?

Boulder County Colorado weeds mosquitoes

2 Responses

There are several considerations with the mosquito questions.

1. Do whatever is possible to keep the water flowing, because mosquitoes breed only in standing water.

2. The water can be treated with a bacterial insecticide called Bti. There are several formulations, e.g., floating briquets or granules. Choose the one that seems the most appropriate for your situation. Bti is used widely and considered to be relatively safe.

3. Animals should be kept away from the wet areas during times of peak biting.

4. Mosquitoes often travel long distances to feed, so it is possible that the ones on your property may be from somewhere besides your pasture. For this reason you should also follow personal protection recommendations, such as using repellents, long sleeve shirts, etc. The Fight the Bite website at the Colorado Department of Public Health and the Environment is very good in this regard.

I'm not that familiar with weed management, so I will ask the eXtension people to find someone to help you with that question.

The weed management depends on the exact ID of the weed. Can you send me either a description of the thistle or a photograph so that I can identify it? Most livestock will not eat thistles. They might eat the flower but not enough of the plant to manage it. Also if the thistle is in the wet area, you do not want to let the livestock spend a lot of time in that area. You can contact me at or 303-678-6176