‍Appendix F: Mosquito Abatement

FEMA provides reimbursement for mosquito abatement measures at the written request of state, local, Tribal Nation, and territorial (SLTT) public health officials after FEMA consults with the Centers for Disease Control and Prevention (CDC). Proper execution of these measures is restricted to specific biological and situational triggers to ensure that assistance directly addresses immediate post-disaster health threats.

I. Core Eligibility Triggers

To qualify for Public Assistance (PA) funding, vector control interventions must be substantiated by written documentation proving at least one of the following conditions:

A. Disease Transmission Evidence

• Documented higher levels of disease-transmitting mosquitoes in the impacted area following the disaster incident.
• A significant number of disease-carrying mosquitoes in the area due to an expansion of incident-related standing water.
• Potential for disease transmission and human exposure based on the detection of arboviral diseases in sentinel organisms (poultry, wild birds, mosquito pools) prior to the incident, discovered during surveillance, or via pre-incident human cases.

B. Responder Threat Evaluations

• A formal determination that a significant increase in the mosquito population or a shift to biting mosquito species poses a direct threat to emergency workers required to work outdoors, thereby significantly hampering response and recovery efforts or representing a threat to public health and safety.
• Such claims must be backed by data showing an abnormal rise in landing rates or trap counts, or significant changes in species composition when compared directly to pre-incident surveillance results.

C. Secondary Medical Infections

• Official verification from medical facilities within the affected area that an increase in the general public's exposure to mosquitoes has directly resulted in secondary infections, especially among vulnerable populations with weakened immune systems (the elderly, the very young, or the sick).
• This commonly applies when increased numbers of residents in areas with extended power outages are forced to open doors and windows for air circulation.

II. Surveillance & Staging Ingestion Fields

Where possible, a determination of the need for vector control measures must be based on surveillance data provided by local agencies or conducted as a component of the emergency response. Similarly, termination of control efforts must be driven by density drops and a reduction in disease exposure.

Mandatory Documentation Tracking Index

Applicants must compile and submit the following data index to justify that the chosen mosquito management option is necessary and reasonable:

• Pre- and post-disaster mosquito population density estimates, including detailed species composition profiles.
• Arbovirus transmission activity indices and explicit tracking locations, consisting of infection rates in mosquitoes, seroconversion in sentinel chickens, equine cases, or human cases.
• The exact amount and type of flooding (saltwater vs. freshwater; coastal vs. inland).
• The precise extent and geographical location of structural damage to local housing.
• The location, extent, and anticipated duration of public utility power interruptions.
• The anticipated timeline and footprint of ongoing cleanup and recovery operations.
• A comprehensive description of the type of mosquito management required (aerial vs. ground-based), the application duration, and specified target zones accompanied by clear cost estimates.

III. Authorized Abatement Methods

To preserve project eligibility, all insecticide formulations must be approved and registered by the U.S. Environmental Protection Agency (EPA) for use in urban areas for mosquito control. Applications must be executed according to label directions and precautions by appropriately trained and certified applicators, comply with all SLTT laws, and align directly with CDC.gov guidance.

Technical Intervention Index

Eligible mosquito abatement measures are categorized into three operational functions:

1. Adulticiding

The ground or aerial spraying of chemical insecticides to kill adult mosquitoes.

2. Larviciding

The application of chemicals, including timed-release methoprene briquettes, by ground or air to target and kill mosquito larvae or pupae within standing pools.

3. Breeding Habitat Removal or Alteration

The modification of potential breeding habitats to make them unsuitable for mosquito breeding or to facilitate larval control. Reimbursable sub-activities are limited to:

• Draining or physically removing standing water located in close proximity to homes, schools, sheltering facilities, and local businesses.
• Increased dewatering through the direct pumping of existing public drainage systems.
• Dissemination of warning information in an accessible and effective manner (such as public service announcements, newspaper campaigns, or inserting flyers directly into residents' water bills) to instruct residents to remove standing water resources from private properties.

IV. Terminology Frameworks

Arbovirus

A virus utilizing arthropods as vectors that is transmitted via feeding to a definitive host.

Landing Rate

An adult mosquito surveillance measure utilizing human volunteers as bait, expressed as the number of mosquitoes landing per minute.

Methoprene Briquettes

A larvicide formulated with an insect growth-regulating hormone mimic that prevents the normal maturation of insect larvae, set inside a timed-release charcoal-like carrier.

Sentinel Organism

An organism, usually fowl, purposely exposed to mosquito bites outdoors to monitor pathogen transmission by mosquitoes.

Seroconversion

The development of detectable antibodies in the blood of a sentinel organism directed against an infectious agent.

Trap Count

The number of female mosquitoes captured in a trap receptacle each night the traps are actively set.

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