Mosquito Control Spray Activities
A significant component of the Mosquito Control Section's operation involves adulticiding--more commonly referred to as "spraying." Our Ultra Low Volume (ULV) Spraying Program is an effective method to control populations of adult mosquitoes.
There are two primary categories of spray activities, and it is important to note the difference:
1. Routine Adult Mosquito Control
During mosquito season, the department will conduct routine ULV spraying in participating communities on a weekly basis. Each community is assigned a specific night of the week.
Community schedules are available by county on the Mosquito Control homepage. For more information on routine ULV spraying, click here.
2. Unscheduled Mosquito Control
In addition to routine activities, we work closely with the Maryland Department of Health and local health departments in response to any concern of mosquito-borne illness. Once health officials determine a need for response, mosquito control personnel will survey the affected area to eliminate potential breeding zones and determine if there is a need for further treatment.
If there are enough adult mosquitoes present in the area, personnel will use backpack sprayers to apply Talstar P Professional—a bifenthrin-based adulticide—onto foliage where mosquitoes rest in order to control adult mosquito populations.
In certain cases, the state may determine a need for unscheduled truck-based ULV fogging in response to a public health concern.
In the event of an unscheduled spray, the department will issue public notice. All notices will be posted on the MDA website and on Twitter @MdAgDept. The department also maintains a Mosquito Spray Alert Hotline: 410-841-5737.
In the event of a disease-related unscheduled spraying, any existing spray exemptions in the affected areas will be temporarily suspended.
For information about the types of pesticides used in truck-mounted and aerial spraying, click here.
For information about how to prevent breeding mosquitoes in your yard that could carry Zika, see our Zika Awareness Page
A Note About Non-Target Organisms
We are very concerned about the effects of our activities on
non-target organisms, like honeybees and bats. We only conduct truck mounted
spraying or misting at night. Bees are not active at night. The droplets in the
spray have an extremely small diameter. The surface to mass ratio of these
droplets is such that these droplets do not leave residue on surfaces. They are
like tiny parachutes. When they are pulled down by gravity, drag keeps them
from falling. The point is that these droplets do not land or stick on
surfaces. When bees become active the next day and crawl across surfaces, those
surfaces do not have any pesticide from our spray. The droplet size averages 15
micrometers. There are 1000 micrometers
in a millimeter. We must have our
machines tested, by law, twice a year. We announce all unscheduled sprays on @MdAgDept (Twitter) and through press releases. If you would like to receive notice of
all UNSCHEDULED spraying, send your email to us at: mda.news@maryland.gov. See scheduled spraying here.
