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.
SCHEDULE (Updated december 9, 2019)
December 9, 2019
Portland is separated into four areas for mosquito spraying.
The City uses two adulticides--Mosquitomist ONE ULV and Biomist 4+4 ULV.