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Mosquitoes of the Florida Keys 

Monroe County has a tropical environment and is home to over 50 different species of mosquitoes. Listed below is a brief description of the mosquito life cyle followed by information about the most common mosquitoes  found in the Florida Keys: 

 

A close-up of a mosquito feeding on human skin.
Aedes aegypti mosquitoes are not the most common in the Florida Keys, but  its  ability to vector diseases such as Dengue Fever, Yellow Fever and Zika make them a special concern for FKMCD. 
Mosquito Biology 
Diagram of a mosquito life cycle with stages: eggs, larva, pupa, adult mosquito.

All mosquitoes require standing water or moist soil to reproduce, but the type of water they prefer really depends on the species.

Some mosquitoes prefer containers, such as tires, tree holes, buckets, and water troughs.

Other species prefer water with lots of organic material (leaves, grass) that is very stagnant. Still others deposit their eggs  primarily in swamps and marshes, some fresh water, and some salt water.

Female mosquitoes bite humans and/or animals and use the blood as a protein source to develop her eggs.  Otherwise, mosquitoes mostly rely on nectar as a primary food source. 

The eggs are deposited in or near water. They then hatch (some require flooding while others hatch immediately), and begin larval and pupal development.

Development from egg to adult can be completed in as little as 6-7 days in the summer.

The egg to larva to pupa to adult life cycle of the mosquito is called "complete metamorphosis" and is similar to the life cycle of a butterfly.

Some species will bite almost any type of animal, while others are very specific. Different species vary in their preferred time to feed, but many feed during dawn or dusk.

Black Salt Marsh Mosquito 
A mosquito on skin, likely feeding.
Black Salt Marsh Mosquito 

Black Salt Marsh Mosquito

The Black Salt Marsh Mosquito (Aedes taeniorhynchus) is the most common mosquito in the Florida Keys. This mosquito is an aggressive biter that creates havoc during outdoor activities, especially at dawn and dusk. The Black Salt Marsh mosquito is a migrating mosquito that is often seen moving into the Florida Keys from the Everglades during “blow-ins”.  FKMCD research projects have shown this mosquito can also migrate  from uninhabited offshore islands as well.

Black Salt Marsh mosquito larvae are found in fresh and brackish water pools near salt marshes. The adults are fierce biters and strong fliers. These mosquitoes are controlled mainly by aerial larvicide and adulticide. 

Aedes aegypti 
A close-up of a mosquito feeding on human skin.
Aedes aegypti mosquito. 

Aedes aegypti, commonly called the Dengue or Yellow Fever Mosquito, is the most common container inhabiting mosquito in the Florida Keys (especially in Urban Areas).

Commonly associated with people and homes,  Aedes aegypti  larvae are most commonly found breeding in artificial containers such as trash cans, flower pots, buckets, coolers, children’s toys, birdbaths, etc. The best way to eliminate this mosquito is to dump water around your home and eliminate places for water to collect when it rains.

This mosquito is a vector for several diseases such as Zika, Dengue, Chikungunya, Yellow Fever and  others.

Southern House Mosquito 
A close-up of a mosquito feeding on skin, filling its abdomen with blood.
 Southern House Mosquito (Culex quinquefasciatus). 

Culex quinquefasciatus, commonly known as the Southern House Mosquito, is a medium-sized brown mosquito that is found in the southern United States and is present in the Florida Keys.

This nighttime-active, opportunistic blood feeder is a vector of many  pathogens, several of which affect humans.

Throughout much of the southern U.S., Cx. quinquefasciatus is the primary vector of St. Louis Encephalitis virus (SLEv) and can transmit West Nile virus.

Larvae of these mosquitoes are found in containers but can also be located in drains and discarded tires. 

No-See-Ums (Biting Midges) 

Biting midges can be a nuisance to campers, fishermen, hunters, hikers, gardeners, and others who spend time outdoors during early morning and evenings, and even during the daytime on cloudy days when winds are calm. They will readily bite humans; the bites are irritating, painful, and can cause long-lasting painful lesions for some people.

A close-up of a small insect with delicate wings and long legs.
No-See-Um (Biting Midge) under magnification. 

A common observation upon experiencing a bite from this insect is that something is biting, but the person suffering cannot see what it is. Biting midges are sometimes incorrectly referred to as sand flies. Sand flies are insects that belong to a different biological group and should not be confused with the biting midges.

In the tropics, the larval habitat of many species is in rotting fruit, bromeliads, and other water-holding plants. Other larval habitats include mud, sand, and debris at edges of ponds, lakes and springs, tree holes, and slime-covered bark. The larval stage can last from two weeks to a year, depending on the species, temperatures, and geographic area.

Historically, management methods included diking and drainage of marshlands to reduce the habitats used by the immature stages. The insecticide DDT was used to target the adult stage. Currently, larval habitats are not targeted in control efforts because of the extensive amount of area that the habitats may cover, some negative environmental impacts resulting from changing water flow patterns of large areas, and the spotty spatial distribution of larvae within a given habitat.

Applications of insecticides targeting the adult stage are not efficient.

While this type of application may kill biting midges active on a given night, they are continually dispersing from the larval habitat and entering areas of human activity. It would require insecticide applications on a daily basis in some areas, and this is not efficient or environmentally sound. Many government agencies that provide mosquito control services receive calls about biting midges. However, most of the programs are not mandated or allowed to respond by providing control measures.

Homeowners can install proper screening for windows and patios to prevent no-see-ums from entering residences and outdoor areas used for leisure and entertaining. Most biting midges can pass through 16-mesh insect wire screen and netting, so a smaller mesh size is required. The small mesh size does limit air flow through the screens. Additionally, because no-see-ums are so small and are weak fliers, ceiling and window fans can be used at high speeds to keep no-see-ums out of small areas.

Repellents containing DEET (N,N-diethyl-meta-toluamide) typically used as mosquito repellents are also labeled for use against no-see-ums and can be applied prior to exposure to the biting midges. It is important that the directions for application that are printed on the label are followed for any product used as a repellent.

*Information found at http://entnemdept.ufl.edu/creatures/aquatic/biting_midges.htm

County residents and visitors are encouraged to contact the Florida Keys Mosquito Control District at 305.292.7190 if they have any issue or concerns pertaining to Mosquito Control in the Florida Keys. 

County residents can also place a 'service request' by clicking HERE .