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.  

Portland is separated into four areas for mosquito spraying. The City uses two adulticides--Mosquitomist ONE ULV and Biomist 4+4 ULV.

Mosquitomist Safety Data 

Biomist Safety Data

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.


JULY 11, 2019--City wide surveillance/monitoring underway.

Updated July 11, 2019