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Mosquito Spraying in Delaware



The Mosquito Control Section uses a Spray Zone Notification System to let residents know when and where they plan to apply pesticides to control mosquito populations.

The DNREC Mosquito Control Section has divided the state into 216 numbered spray zones to help manage planned mosquito spraying. You can use the spray zone map to learn when and where the state plans to apply pesticides each day to control mosquito populations. 

Mosquito Control Section staff update the map each day by 4 p.m. Spray zones with planned activity are highlighted on the map. Notifications specific to spray zones with planned activity are sent via the Delaware Notification Service.

The Mosquito Control Spray Zone Map only identifies planned spraying by helicopter, airplane or truck-mounted fogger. Also, in most cases, highlighting means that spray operations are planned within an area, not that the entire zone will be sprayed.

Residents can also check the Mosquito Control Spraying Calendar for information on planned spray applications.

Using the Spray Zone Map

Map of Delaware, showing the grid pattern of mosquito spray zones for which users can sign up for notifications.

First, Find Your Zone

Use the Spray Zone Map to identify which zones you want to be notified about. You can pan, zoom and browse. Or enter an address to get right to your zone.

Click within any block to see the spray zone number. This is the number you will use to set up your notification.

Next, Register for Notifications

The Spray Zone Notification System uses the Delaware Notification Service to send out texts, phone calls and e-mails.

If you haven’t already registered for one of the many other notifications offered by the state, you will need to set up an account. It’s easy. Simply click on “Sign Me Up!” to create an account.

You’ll create a username and password and choose from various options about how you want to get your notifications.

Now, Select Your Notifications

To subscribe to specific spray zones, navigate to the DNREC section of the subscriptions list (use the orange arrows to expand the “STATE OF DELAWARE” section and the DNREC section) and open the “DNREC-MOSQUITO CONTROL” section.

From here, you can select the zones for which you would like notifications. 

Additional Resources

Mosquito Control Pesticide Management Discharge Plan (PMDP)

Spray Threshold Criteria

Fogging Guidelines for Communities

Fogging Guidelines for Rural Homeowners

Adult Mosquito Control and Domestic Honeybees
– Standard Operating Procedures (SOPs)
– Background and Rationale for SOPs




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