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Here, at North Morrow Vector Control District we use an Integrated Mosquito Management" approch to mosquito control. This concept utilizes a combination of surveillance, biological, source reduction, larval mosquito control and adult mosquito control, in concert, rather than using only one of these methods.

Source Reduction Mosquito Control

Source reduction involves removing or changing the aquatic larval habitats by means of environmental manipulation. It is a broad category including several methods. One of these methods could be regulating water levels or irrigation practices. Another would be to eleminate an unneccassary water source such as, turning over unused water troughs, buckets, wading pool or any object that could be holding water for more that 5 to 7 days.


Mosquito Larvae Surveillance
Mosquito Field Technician checking for mosquito larva in a water source.
Checking for mosquito larvae in a water source.

Trained NMVCD field technicians survey mosquito breeding sources to determine if mosquito larvae are present. Field technicians know where to go by using a tablet that has a map of the county and markers that show the location of known mosquito breeding sites. The tablet is where all survey and treatment (if any performed) information is recorded for that specific site, 


Biological Mosquito Control
small fish
Gambusia affinis A.K.A. "mosquito fish"

Gambusia affinnis (mosquito eating fish) can flourish in a wide range of temperatures and locations. They are silvery in color, but may adjust over time to better merge with their habitat. Gambusia range in size from 1 to 3 inches. These fish have a hearty appetite for mosquito larvae and are capable of consuming several in a day.


Larval Mosquito Control
May contain: grass, plant, pond, outdoors, nature, water, photography, glove, clothing, hardhat, helmet, portrait, person, head, face, hiking, leisure activities, adventure, and shorts
NMVCD Field Technician applying granuals to a mosquito breeding site.

Involves utilizing the application of products that are specifically targeted to the immature mosquito larvae or pupae. The products that we use are called larvicides and are classified as either bacterial, spinosyns, or insect growth regulators.

Bacterial larvicides use mosquito-specific bacteria, Bacillus thuringiensis israelensis (Bti) being most common, that, once ingested, produces proteins that disrupt the midgut of mosquito larvae. 

Spinosyns use Spinodad, a toxin produced from the fermentation of soil bacteria which interferes with the larva's nerve function.

Insect growth regulators, primarily S-Methoprene, release hormones that prevent mosquito larvae from progressing to the adult stage. These products control mosquito larvae very well, but are not effective against mosquito larva in their pupae stage.

When the control of pupae is needed, surface oils  can be used to prevent larvae and pupae from breaking through the water's surface tension and blocks their breathing tubes depriving them of oxygen until they drown.

It is important to note that more mosquitoes are controlled in their larval stage than in their adult stage.

Adult Mosquito Control
White chevy truck with ULV (Ultra Low Volume) in the bed with two men testing droplet size being dispensed from machine
Before every mosquito season begins, fogging trucks are droplet tested to ensure the products used are performing efficiently according to the label.

Involves a process we call adulticiding or fogging. This is the last step in or Integrated Mosquito Management approach. Adulticiding is triggered when mosquitoes become mature, flying adults, and our adult surveillance program as well as confirmed notifications from the public trigger the need to fog. Fogging takes place during the evening to night time hours when mosquitoes are most active. 




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