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State Mosquito Advisory For Wednesday, Sept. 25 - Second Round Of Spraying Set For Tonight, Weather Permitting

PROVIDENCE The second round of aerial mosquito treatments will likely begin tonight, September 25, depending on weather conditions, the Department of Environmental Management (DEM) and the Rhode Island Department of Health (RIDOH) announced today. Whether the two spraying zones one surrounding West Warwick and one in southwestern Rhode Island will be treated at the same time or back-to-back will be a flight-time decision. The flight plan will be finalized just before takeoff, out of the Plymouth, MA, airport. Operations are expected to be conducted between the hours of 6:30 PM and 4 AM Thursday, September 26.

An approximate map of the two areas to be sprayed is attached. These areas and the two additional areas sprayed September 8 to 10 are considered critical risk areas for EEE. Aerial spraying depends on calm conditions and temperatures above 58 degrees and timing is always subject to change. For example, in the earlier round of spraying, state officials estimated that parts of Westerly, Hopkinton, and Charlestown would be sprayed September 9 but ground fog moved into the area, forcing a postponement of the treatment until September 10.

The spray area surrounding West Warwick includes all West Warwick and parts of Cranston, Warwick, East Greenwich, West Greenwich, Coventry, and Scituate. Some of this area was previously sprayed on September 9, but officials have expanded this zone westward to Route 102 in Coventry and both westward and southward in West Greenwich. The southwest area to be sprayed includes much of Westerly and parts of Hopkinton and Charlestown that were already sprayed on September 10. This expanded area of critical risk now also encompasses new swaths of Hopkinton, Richmond, and Charlestown as well as the southwestern section of South Kingstown.

The areas to be sprayed have been identified using several factors, including information about human cases of EEE, cases of EEE in non-human mammals, positive mosquito samples in Rhode Island and in neighboring states, and information about the habitats in which mosquitoes most readily breed. More information on health and spraying is available here. For FAQs on the impact of spraying on pets and livestock, click here. Rhode Islanders may call 2-1-1 for more information.

EEE is a rare but serious illness that occurs when people are bitten by infected mosquitoes. It can affect people of all ages. In Rhode Island in 2019, there have been three human cases of EEE with one case resulting in death. Massachusetts has experienced 10 human cases with three deaths this year and yesterday Connecticut confirmed that a second resident has died from the disease this year.

Aerial spraying is only one tool used to combat risk from mosquito-borne disease. The foundation of all risk reduction remains personal protection (mosquito repellent, long sleeves and pants, avoiding outdoor activities between dusk and dawn, repairing window and door screens, and dumping standing water). If possible, people should limit their time outdoors at sunrise and sunset. If they are going to be out, people should wear long sleeves and pants and use bug spray. Aerial spraying effectively reduces the risk of mosquito-borne disease, but it does not eliminate the risk completely. In addition, fewer mosquitoes are active as evening temperatures get cooler, but those mosquitoes that are active are more likely to be infected with EEE.

The risk from mosquito-borne disease will continue until the first hard frost. However, mosquito spraying efficacy substantially decreases once nighttime temperatures fall below 60 degrees and cannot occur once temperatures fall below 50 degrees.

Related links

  • Department or agency: Department of Environmental Management
  • Online:
  • Release date: 09-25-2019

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