Mosquitoes and West Nile Virus in Larimer County
West Nile virus (WNV) is a disease spread from infected mosquitoes to people. In 2023, we saw record numbers of mosquitoes that can carry this virus in Larimer County, including in the Town of Berthoud.
The Town of Berthoud currently has a mosquito management program that uses larvicides to control mosquito populations. Larvicides are insecticides that target mosquito larvae, helping to manage mosquitoes both indoors and outdoors. Larvicides do not kill adult mosquitoes.
Mosquito Surveillance and Adulticides
During the summer months, mosquitoes in Berthoud are collected in traps and tested for West Nile virus. The Town of Berthoud’s decision-makers rely on this surveillance data to determine when adulticides may be needed to reduce mosquito abundance and prevent human cases of West Nile virus disease. Adulticides are insecticides that are sprayed in the air to kill adult mosquitoes. When used as directed, adulticides are safe for people, pets, and the environment.
Enhancing Mosquito Surveillance in Berthoud
A new collaborative project will increase the number of mosquito traps in Berthoud to better understand the risks of West Nile Virus in this community. The project is a partnership between the Town of Berthoud, the Centers for Disease Control and Prevention (CDC), Vector Disease Control International (VDCI), Colorado State University lab, and the Larimer County Department of Health and Environment (LCDHE).
The project will expand mosquito surveillance testing by adding five new mosquito traps to the existing five, making a total of ten traps in Berthoud. With more traps, we can gather more data to help inform the Town’s decisions about using adulticide spray. Later this fall, the Town of Berthoud will decide whether to keep the additional traps through 2025 and beyond.
Protecting Yourself from Mosquito Bites
Everyone can take steps to protect themselves from mosquito bites:
- Use Environmental Protection Agency (EPA)-registered insect repellents.
- Wear loose-fitting, long-sleeved shirts and pants.
- Wear clothing and gear treated with permethrin.
- Control mosquitoes both indoors and outdoors.
For more information about this project, please contact Erika Cathey at the Larimer County Department of Health and Environment at ecathey@larimer.org or (970) 217-7183.
