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.

SCHEDULE   (Updated juLY 2, 2020)

DATEROUTETIMEREMARKS
July 2, 20201 - 4PMEffective swath spraying tonight.
July 2, 20201 - 4 
Larviciding, mosquito counts, and spot spraying of parks, ditches, and fields.
July 1, 20201 - 4
Larviciding, mosquito counts, and day spraying underway.
June 30, 20201 - 4
Larviciding, mosquito counts, and day spraying as wind allows.
June 29, 20201 - 4
Larviciding and mosquito counts underway.
June 26, 20201 - 4
Rain event.
June 25, 20201 - 4PMScheduled day spraying, larviciding, and mosquito counts underway.
June 25, 20201 - 4AMScheduled spraying of parks and ditches.
June 24, 20201 - 4 
Larviciding and mosquito counts continue, rain event in forecast.
June 23, 20201 - 4
Larviciding and mosquito counts continue, rain event in forecast.
June 22, 20201 - 4
Larviciding and mosquito counts underway.
June 19, 20201 - 4
Surveillance and pretreatments underway.
June 18, 2020

Rain event.
June 15, 20201 - 4
Larviciding and mosquito counts continue.
June 12, 20201 - 4AM
Scheduled residential spraying citywide, some mid-day spot spraying.
June 11, 20201 - 4AMLarviciding, mosquito counts, and day spraying continues.
June 10, 20201 - 4PMScheduled residential spraying citywide.
June 10, 20201 - 4AMLarviciding, mosquito counts, and day spraying continues.
June 9, 20201 - 4PMScheduled residential spraying citywide.
June 9, 20201 - 4AMPretreatments and day spraying continues.
June 8, 20201 - 4PMScheduled residential spraying citywide.
June 8, 20201 - 4AMPretreatments and day spraying underway.
June 5, 20201 - 4 AMLarviciding and mosquito counts underway.
June 4, 20201 - 4AMSurveillance and pretreatments underway.
June 1, 2020 

Rain event.


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