Process EPA Uses to Develop Core Maps for Pesticide Use Limitation Areas

• Core map development process summary
• Species check out process
• Identification of species for core map development and how to check out species to develop core maps
• Results of applying core mapping process to data
• Table with priority species

The Environmental Protection Agency (EPA) identifies geographically specific mitigations to protect federally listed endangered and threatened (“listed”) species and/or designated critical habitat from the use of a pesticide (or group of pesticides) and communicates those mitigations and where they apply using a web-based system called Bulletins Live! Two (BLT). The locations where those mitigations apply are called Pesticide Use Limitations Areas (PULAs). Thus, the purpose of a PULA is to identify areas where pesticide mitigations apply to conserve one or more listed species and/or designated critical habitat. PULAs focus on areas where pesticide exposures are likely to impact the continued existence of a listed species, which may include a reduction in survival or recovery of the species. Thus, PULAs are intended to focus mitigations to where they are needed to protect populations of listed species.

PULAs are based on “core maps” for a species. A core map identifies areas that are important to a species, which could be its range or its critical habitat, which are both areas defined by U.S. Fish and Wildlife Service (FWS). Sometimes, species ranges are broad and may include areas that are not likely to currently contain a species, as well as areas that do. In those cases, the process EPA uses to develop core maps is intended to identify those portions within a species range that need to be conserved for a listed species and/or designated critical habitat and are relevant to pesticide mitigations (and exclude areas that do not). When developing a PULA, areas next to the core map can then be added to account for pesticide movement from a use site into the core map area and/or impacts to prey, pollination, habitat and/or dispersal that reduce necessary elements for species survival/recovery.

Depending on the location and type of mitigation, a single PULA may include one or more species. EPA has developed a systematic process it plans to use when creating core maps based on the best available data for a species. The process is briefly summarized below and is described more in the core map process document (pdf) (3.8 MB) . The purpose of this approach is to create a transparent framework that developers can use that considers different types of available species data to develop a reasonable core map, resulting in PULAs based on the best information available for a species.

Core Map Development Process Summary

The process for developing a core map involves compiling available information, determining what type of information is most appropriate on which to base a core map, developing the map, and preparing documentation. These steps are briefly summarized below and are described further in EPA’s core map process document (pdf) (3.8 MB) .

1. Compile available information for a species: This step involves compiling information on a species that can be used to identify how best to develop a core map. Information for a species should be predominantly based on recent FWS documents available on the Environmental Conservation Online System (ECOS) website. This step also includes compiling known locations/occurrences of the species from FWS documentation and acquiring spatial data for species range and critical habitat (CH) from ECOS or EPA’s species and critical habitat data services.
2. Identify the most appropriate type of core map: This step involves identifying the type of core map most appropriate to represent areas necessary to conserve the species based on the information collected in Step 1. Core maps described in the mapping process document can be based on defined areas that FWS has already identified for a species, such as critical habitat or range. Core maps can also be based on biological information for a species (i.e., its preferred habitat, elevation, soil type, foraging range, etc.). A core map can be based only on a species’ range, critical habitat, or biological/location information, or a combination of these areas. For example, a critical habitat core map may be supplemented with additional areas that may be identified in FWS’ documentation or by occurrence data.
3. Develop the core map: This step involves developing a map to represent locations important to the conservation of a species based on the type of map identified in Step 2 using GIS software and spatial data. This step could be very simple if, for example, a species core map is based solely on a species’ range or critical habitat. This step could also be quite complicated in cases where core maps are based on species habitats, occurrence data, or other biological information. A more detailed process on developing a core map can be found in EPA’s core map mapping process document, available at the link below.
4. Documentation: The final step involves creating documentation that describes the development and supporting data of the core map. Documentation will ensure the transparency of the decision process and data used to generate the core map and will be used for the quality check review.

These steps are described in detail in the core map process document (pdf) (3.8 MB) .

Species Check Out Process

EPA is developing core maps and also recognizes that non-governmental entities may wish to develop core maps using EPA’s process. EPA has identified species needing core maps to support PULA development related to its Endangered Species Act Strategies and regulatory actions. EPA intends to develop core maps for all species that may need PULAs but recognizes that developing maps for hundreds of species will take time. Therefore, EPA is prioritizing species with respect to timing of core map development with highest priority species identified as needing mitigations through a new active ingredient registration process and species included in Herbicide Strategy PULAs followed by species in Insecticide and Rodenticide Strategy PULAs. These priorities are only related to PULA development, and do not imply that any particular species is more or less of a priority to protect.

Species that are included in these priority areas are listed below. Individuals wanting to follow the approach described in the core map process document (pdf) (3.8 MB) can identify their species of interest by completing the information on the “Contact EPA PULA Core Maps Team” page. Please note that you will need the species Entity ID number from the species list below. To prevent multiple individuals from working on the same species, the requestor will receive a confirmation email from pula_core_maps@epa.gov that the species have been checked out from the list and development can begin. After finishing the core map, the GIS data, documentation, and other supporting materials can be uploaded to EPA’s GeoPlatform. EPA will create an EPA GeoPlatform account on behalf of the developer the first time a species is checked out and the developer will receive an email from geoservices@epa.gov with their username and password. Additional details on how to upload materials to the GeoPlatform can be found in the core map process document (pdf) (3.8 MB) . The developer will receive an email two months after checking out species to confirm core map development is in progress. Three months after checking-out a species, those species will be automatically checked back in and made available again for a different individual to check-out. After sending materials for checked out species, an additional species may be selected using the same process.

The table with the species list will be updated routinely to add species as needed and reflect changes in the status (available, checked out, under review, interim, and final). Once a core map has gone through a quality assurance/quality control review and considered reasonable by EPA, the core map will be added to the available core map GIS layer.

Identification of Species for Core Map Development and How to Check Out Species to Develop Core Maps

1. Identify your species of interest from the table below (one at a time).
2. Contact us with your species selections by including information on the “Contact EPA PULA Core Maps Team” page.
3. Wait for the confirmation email from EPA PULA Core Maps Team. The email will come from pula_core_maps@epa.gov email address.
4. Finish your core map and share the information (GIS data, documentation, and other supporting materials) through GeoPlatform account on behalf of the developer the first time a species is checked out.

Core Mapping Results to Date

As of June 2025, EPA has made available 39 interim core maps. Interim core maps will become final once reviewed by the U.S. Fish and Wildlife Service. Some of these maps were developed by EPA and some in consultation with other stakeholders. EPA and stakeholders are continuing to develop interim core maps, and hundreds of maps are currently in development. 

Interim core maps for the 39 species that have undergone this process are refined considerably compared with species ranges. Interim core maps for these species represent, on average, a 90% reduction in area when compared to species ranges. In some cases, interim core maps are the same as the species ranges. In those cases, the map developer and EPA have evaluated the available data for the species and agree the species range is refined and represents a reasonable basis to develop pesticide use limitation areas (PULAs). The table below identifies species for which interim core maps are or will be developed and the status of their maps.

Table With Priority Species

Definition of status terms: