For infectious disease declarations, FEMA works with the CDC and issues disaster-specific guidance on which measures are eligible. Mosquito abatement is eligible when a public health official validates a specific threat in writing, and only for the increase over normal spending.
The public health official’s written validation, and three years of normal mosquito abatement spending.
Keep a clean three-year history of routine mosquito spending. It sets the baseline FEMA deducts.