June 2017: Larvicide Application in the Ward

June 5, 2017
Starting the week of June 5, 2017, and continuing through the end of June, staff under contract with the CDPH will begin dropping larvicide in catch basins throughout the City. This annual activity is done to decrease the number of mosquitoes that can transmit the West Nile virus.
Additional information on this effort:
  • What is a larvicide? A larvicide is a type of insecticide used to kill or interrupt the development of immature forms of mosquitoes, preventing them from becoming adults.
  • Is the larvicide safe? This larvicide is registered for use by the EPA and is safe for humans as well as for animals that may come in contact with it, including fish, other aquatic life and birds.
  • How will I or my constituents know when the larvicide is being placed in my neighborhood? Crews will be easily recognized: they will be wearing orange vest and will be walking up and down the street placing the larvicide in catch basins. Crews will be escorted by a van with the contractor’s insignia – ‘Vector Disease Control International.’
  • How is the larvicide used? The larvicide is uniquely shaped to fit between the small openings in the catch basins. Once in the catch basin, small amounts of the active ingredient are released over time.
  • What larvicide is use? The brand name of the larvacide is Fourstar® Briquets.
  • Which areas of the City will larvicide be placed? Larvicide is placed in areas of the City where data have shown an increased likelihood of identifying mosquitoes infected with the West Nile virus. A map showing the locations of the larviciding effort is attached.
  • Does this effort help address Zika virus? This effort is primarily focused on combating West Nile virus by decreasing the number of mosquitoes that can transmit this virus. Though Zika virus is transmitted by mosquitoes, the risk for Chicagoans for contracting Zika virus is low, as the main species of mosquito that transmits this virus is not native to Chicago. However, we will be placing traps throughout the City to monitor for the types of mosquitoes that can transmit Zika virus.