Aerial Mosquito Control Operations

Science-Driven Treatments from the Sky

PCMCD uses helicopters and UAS/drones to conduct aerial mosquito control operations that are safe, strategic, and highly effective. These aerial applications allow us to treat large areas quickly and efficiently based on real-time surveillance and scientific data.

Each aerial mission is guided by mosquito population trends and environmental factors, including rainfall, tidal activity, water presence, direct larval sampling, and adult trap collections. Technicians inspect these areas for mosquito larvae or adult activity and use this data to determine which product to apply, what method to use, and when to conduct the treatment for maximum impact.

Why Aerial Treatments Are Necessary

Certain mosquito habitats, such as remote salt marshes or widespread residential areas, can’t be treated effectively with trucks or hand crews. Aerial treatments allow us to rapidly respond to rising mosquito populations, suppress larvae before they hatch, and reduce disease risks throughout the county.

We align treatment strategies with the mosquito’s life cycle:

• Larval treatments prevent emerging adult mosquitoes by targeting them in standing water.
• Adult treatments target flying, biting mosquitoes already active in the area.

Each method uses a specific product and application setup.
 

1. Granular Larvicide Applications Via Helicopter (Daytime)

• When it’s used: To target larvae in wetlands, ditches, floodplains, and marshes after rainfall or tidal events, or as a preventive treatment before eggs hatch.
• How it works: A granular larvicide is spread from specialized hoppers mounted on either side of the helicopter. These granules must fall through vegetation and reach the water where mosquito larvae are present.
• Flight pattern: To ensure accuracy, the helicopter flies at low altitudes using steep, rapid turns (called ag-turns), to ensure precise and complete coverage. This is a standard and safe aviation technique used in mosquito control.
• Efficiency & automation: A bulk auto-loading system is used to quickly and safely refill the hoppers with insecticide material between flights. This minimizes manual handling, reduces downtime, and ensures a consistent, uninterrupted application, allowing for fast and thorough area-wide treatment while minimizing environmental disturbance.
• What you might see: A low-flying helicopter making tight, sweeping turns over large natural areas.

2. Liquid Larvicide Applications Via Helicopter (Daytime)

• When it’s used: In urban and residential areas to control Aedes aegypti, a container-breeding mosquito that can transmit dengue, Zika, chikungunya, and Yellow Fever.
• How it works: A liquid mix (usually water and Bti, a natural larvicide) is sprayed from a tank mounted to the helicopter’s underside. Special nozzles on boom sprayers produce droplets small enough to settle into small, often hidden water-holding containers around homes (like flowerpots or rain gutters).
• What you might see: A helicopter spraying mist over residential neighborhoods during daylight hours.

Science-Backed Decision Making

All aerial treatments are guided by field data collected by our field staff. We monitor:

• Environmental data - rain gauges, tide levels, temperature, and breeding site persistence
• Larval sampling to confirm the presence of developing mosquitoes
• Adult surveillance trap counts and disease surveillance data to assess adult mosquito populations and public health risk

Treatments are matched to the life stage of the mosquito to maximize effectiveness and minimize non-target impact. The selection of product and timing is critical and based entirely on scientific evidence.

To support fast-paced operations, helicopter hoppers are refilled using a bulk auto-loading system. This advanced equipment streamlines refueling, reduces human handling of insecticide, and ensures the helicopter can return to the air quickly with properly calibrated material, reducing downtime and increasing treatment coverage with every mission.