Mosquito Control

Mosquito spraying is done on as needed basis. That determination is based on mosquito counts and/or requests by citizens. To report mosquito activity in your neighborhood, please call 361.777.4601.  

The chemicals must make contact with the mosquitoes to be effective, so spraying is scheduled in the early morning and late evening, when mosquitoes are most active. Normal spraying times begin at 4:00 a.m. and at 8:00 p.m. Wind and weather conditions affect the effectiveness of mosquito control efforts. If winds are too strong or in wet conditions, spraying is not effective and may be rescheduled. 

Please see the current spraying schedule below. Spraying schedules from previous months are posted below the current schedule. You can find the spraying route map and information on the chemicals used for spraying below, as well. 

SCHEDULE (UPDATED september 18, 2020)

DATE ROUTE TIME REMARKS
September 19, 2020   1 - 4  AM Scheduled spraying from 4 AM to 7 AM
September 18, 2020   1 - 4  AM Performed scheduled spraying from 4 AM to 7 AM
September 17, 2020   1 - 4  PM Rain event
September 17, 2020   1 - 4  AM Conducted larviciding, mosquito counts, and day spraying
September 16, 2020   1 - 4  PM Scheduled spraying from 8 PM to 11 PM, weather pending
September 16, 2020   1 - 4  AM Larviciding and mosquito counts
September 15, 2020   1 - 4  AM/PM Larviciding and spraying in high count areas
September 14, 2020    PM Rain event
September 11, 2020   1 - 4  AM/PM Conducted larviciding and some spot spraying in high count areas
September 10, 2020    AM Rain event
September 9, 2020   1 - 4  AM/PM Conducting mosquito counts and day spraying
September 9, 2020    AM Rain event
September 8, 2020   1 - 4  AM/PM Conducted larviciding, mosquito counts, and some spot spraying
September 2, 2020   1 - 4  AM Larviciding and mosquito counts
September 1, 2020   1 - 4  AM Larviciding and mosquito counts
August 31, 2020   1 - 4  PM Larviciding and mosquito counts
August 28, 2020   1 - 4  PM Larviciding and mosquito counts
August 26, 2020   1 - 4  AM/PM Scheduled larviciding and mosquito counts
August 25, 2020   1 - 4  PM Larviciding and mosquito counts

Spraying Logs from Previous Months
- Mosquito Control Spraying Log - June 2020
- Mosquito Control Spraying Log - July 2020
- Mosquito Control Spraying Log - August 2020

Map of Spraying Routes
Portland is separated into four areas for mosquito spraying.
Mosquito Spraying Route

The City uses two adulticides--Mosquitomist ONE ULV and Biomist 4+4 ULV.

Mosquitomist Safety Data         Biomist Safety Data