ENY70035 Synopsis of Florida Mosquitoes 1 C.D. Morris2 1. This document is ENY-700-3-5, part of the Mosquito Control Handbook, published cooperatively by the Department of Entomology and Nematology, University of Florida; the Florida Medical Entomology Laboratory, Vero Beach; the Florida Department of Health and Rehabilitative Services, Office of Entomology Services (HRS-ES), Jacksonville; the Florida Mosquito Control Association (FMCS); the St. Lucie County Mosquito Control District; the Indian River Mosquito Control District; the Pasco County Mosquito Control District; Polk County Environmental Services; and the USDA Medical and Veterinary Entomology Research Laboratory, Gainesville, Florida. ENY-700-3-5 was revised April 1992; reviewed March 2000. The electronic edition of the Mosquito Control Handbook is provided by the Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, 32611. Please visit the EDIS Web site at http://edis.ifas.ufl.edu. 2. C.D. Morris, Assistant professor and extension medical entomologist at the Florida Medical Entomology Laboratory, IFAS-University of Florida, Vero Beach. The Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational information and other services only to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin. For information on obtaining other extension publications, contact your county Cooperative Extension Service office. Florida Cooperative Extension Service/Institute of Food and Agricultural Sciences/University of Florida/Christine Taylor Waddill, Dean. The state of Florida has 74 mosquito species, more than any other state. Of these, 33 species can cause pest problems for man and/or domestic animals in all or parts of the state. Thirteen species are capable of transmitting one or more human or veterinary diseases. In this synopsis, the comments on biology describe the species in Florida. The comments on disease describe all the significant associations between that species and important diseases, whether or not the disease is found in Florida. Aedes Florida has 20 species in this genus, probably all of which bite humans. There are about nine pest species in the genus and several species that are important vectors of human and animal diseases. The eggs of most are laid singly on damp soil that becomes flooded periodically. Many species produce a brood whenever the eggs are submersed. Therefore, nuisance problems with species of this genus are closely associated with rainfall and tides, or the human equivalent: irrigation. Adults are strong fliers, and many species can travel over five miles from their breeding sites. Ae. aegypti (Linnaeus) "Yellow fever mosquito" Biology This common, small, black-and-white mosquito bites during the day and prefers to bite humans (particularly on the ankles) rather than other mammals or birds. It is strongly associated with humans and breeds in artificial containers throughout Florida. It is a frequent pest inside and outside houses. Relationship to disease This important mosquito is the major vector of yellow fever and dengue to humans in the Caribbean and South America. Neither of these viral diseases is currently found in Florida, but Ae. aegypti does transmit dog heartworm in the state. Ae. albopictus (Skuse) Asian tiger mosquito Biology
Synopsis of Florida Mosquitoes 2 This small, black-and-white mosquito bites during the day and prefers to bite humans. It is more aggressive than the related species Ae. aegypti. It is strongly associated with humans and breeds in artificial containers, especially discarded tires. This species was introduced from southeast Asia and was first recognized in the state in 1986. It is rapidly expanding its distribution and replacing Ae. aegypti in northern and central counties in Florida. Relationship to disease This mosquito is a major vector of dengue to humans in Asia. While dengue is not present in Florida, the recent introduction of Ae. albopictus into the United States has some officials concerned about the increased potential for epidemics of this viral disease. Ae. atlanticus (Dyar & Knab) Biology This common mosquito breeds in shaded woodland pools and is a severe biter during the day in and near woods. The adults are indistinguishable from Ae. tormentor and are often associated with them, but occur in much larger numbers. Ae. bahamensis Berlin Biology This introduced, tropical mosquito breeds in artificial containers, primarily discarded tires, and may compete with Ae. aegypti for these habitats. It is distributed in areas south of Fort Lauderdale, where it can be a pest to humans at dusk near its breeding areas. It does not always require a bloodmeal to produce eggs. Its low vector potential makes this species a desirable alternative to Ae. aegypti. Ae. canadensis (Theobald) Biology This common, "golden-brown" mosquito breeds principally in woodland pools in the northern part of the state, where it can be a pest to humans during the spring in and near wooded areas. There are two subspecies; the most common being the lighter form, Ae. canadensis canadensis. The darker, rarer form, Ae. canadensis mathesoni, is more southern in distribution. Ae. cinereus Meigen Biology This uncommon small, rather plain, brown species breeds in northern floodwater pools but is not generally a pest to humans. Ae. dupreei (Coquillett) Biology This rare, small, silvery-backed, northern mosquito is similar to Ae. atlanticus. The larvae hide at the bottom of temporary rain pools where they breed, making them difficult to find. Little is known of their biology. Ae. fulvus pallens Ross "The yellow mosquito" Biology This rare, large, yellow mosquito is unmistakable. It breeds in temporary woodland pools and the adults can be fierce biters in the woods. Ae. hendersoni Cockerell Biology This rare, "silver-sided" mosquito breeds primarily in tree holes located in the canopy. The species is restricted to woodlands in north Florida. The adults are difficult to distinguish from its sibling species, Ae. triseriatus. Relationship to disease Unlike its sibling species, Ae. triseriatus, Ae. hendersoni is not known to carry any diseases. Ae. infirmatus Dyar & Knab Biology This Aedes is mostly a woodland mosquito that is a fierce biter even during the daytime in or near woods. The species breeds in temporary woodlands or open grassy pools and is common in the inland
Synopsis of Florida Mosquitoes 3 sections of the state. They can be a serious pest, even entering houses when abundant. Relationship to disease They may play a role in the transmission of eastern encephalitis and dog heartworm. Ae. mitchellae (Dyer) Biology This rare species breeds in temporary pools, particularly in the flat depressions associated with the piney flatwoods in the central part of the state. They are fierce biters and can be a pest in nearby wooded areas. The adults can be easily confused with the more common Ae. sollicitans in coastal areas. Ae. sollicitans (Walker) Eastern saltmarsh mosquito Biology This salt-marsh breeding mosquito is a common and important pest of man along the coasts of north and central Florida. The larvae are found in depressions or potholes on the "high marsh" not reached by daily tides. The females are fierce daytime biters and strong fliers, commonly moving several miles inland and on occasion migrating up to 50 miles. They are sometimes found breeding inland in pastures. Relationship to disease They are capable of transmitting eastern encephalitis and St. Louis encephalitis viruses and dog heartworm. Ae. sticticus (Meigen) Biology This large species is widely distributed in northern Florida but is seldom abundant. It breeds in temporary woodland grassy pools and rain pools during the spring. Ae. taeniorhynchus (Wiedemann) Black saltmarsh mosquito Biology This small, black-and-white mosquito prefers well-sheltered breeding sites in the salt marshes along the southern two-thirds of the coasts, where mangrove and saltwort form the predominant marsh vegetation. Like Ae. sollicitans, they will breed in fresh water and make long migrations. Unlike Ae. sollicitans, they are rarely found breeding in the central part of the state. They are persistent and hard biters and major pests during the day and at dusk. Relationship to disease They are capable of transmitting eastern and St. Louis encephalitis viruses and dog heartworm. Ae. thelcter Dyar Biology This rare species is found only in the Keys, where they breed in temporary rain pools. They bite humans. Ae. thibaulti (Dyar & Knab) Biology This rare mosquito breeds exclusively in stump holes and in cavities at the base of gum and cypress trees. They will bite humans and can be annoying near the breeding sites. Ae. tormentor (Dyar & Knab) Biology The adults are indistinguishable from Ae. atlanticus and are found in association with them, but occur in much smaller numbers. Ae. tortilis (Theobald) Biology This rare mosquito is found in subtropical and tropical Florida. While it will feed on humans, little is known of its biology.
Synopsis of Florida Mosquitoes 4 Ae. triseriatus (Say) Tree-hole Aedes Biology This "silver-sided" mosquito is found statewide. It breeds primarily in tree holes but it will also use artificial containers containing organic debris. The species is common in woodlands, where it can be a fierce daytime biter. Relationship to disease This species is an important vector of the La Crosse strain of California encephalitis in the Midwest. It is capable of transmitting yellow fever and eastern encephalitis viruses and dog heartworm. Ae. vexans (Meigen) Biology This common, widespread species is a floodwater breeder, especially in irrigated areas, and is a major pest to humans and livestock in much of interior Florida. Adults in large numbers commonly fly 15 or more miles from their breeding site. The adults are distinguishable by the narrow, white leg bands. Relationship to disease The species may transmit eastern encephalitis and California encephalitis viruses and dog heartworm. Anopheles Florida has 13 species of Anopheles, most of which breed in permanent bodies of water containing emergent or floating vegetation. All but three breed exclusively in fresh water. The eggs are laid singly on the surface of the water, and breeding is continuous if the temperature permits. During cold periods adult females of most species hibernate in protected sites. Anopheles bloodfeed primarily on large mammals, including humans, and are active after dark. They typically do not fly more than one or two miles from their breeding sites. The genus is noted for its role as the carrier of human malaria, which has been eradicated in Florida. An. albimanus Wiedemann Biology This is a tropical species found only in the Keys. They breed in open sunlit lakes and ponds of fresh or brackish water where there is a vegetative mat. They are strong fliers and enter buildings to feed on humans. An. atropos Dyar & Knab Biology This salt-marsh breeding species occurs throughout coastal Florida but it rarely bites humans in the open. It breeds in more saline conditions than the other salt-marsh breeding Anopheles. An. barberi Coquillett Biology This small, rare, tree-hole breeding species also uses artificial containers to breed. It bites humans and can be a persistent pest, but only near its breeding sites. This is the only Florida Anopheles to diapause in the larval stage. An. bradleyi King Biology The adults of this species are nearly indistinguishable from An. crucians and An. georgianus, and the species is sometimes referred to as the saltwater relative of An. crucians. The larvae are found primarily in brackish water where the salt concentration is below 1.5 percent. An. crucians Wiedemann Biology This species is the common freshwater member of the An. crucians group, which also includes An. bradleyi and An. georgianus. Larvae are more common in acid waters, either permanent or temporary, where there is aquatic vegetation. It is typically the dominant Anopheles in the southern half of the state. Females bite at night and during the day in the woods. They also enter houses. The vector
Synopsis of Florida Mosquitoes 5 potential of An. crucians is low for malaria and the encephalitis viruses. An. georgianus King Biology This member of the An. crucians group is rare and its biology is not well-known. The adults are nearly indistinguishable from An. crucians and An. bradleyi but the larvae are apparently restricted to shallow seepage areas at the heads of small streams. An. perplexens Ludlow Biology This uncommon species is very dark and otherwise looks like An. punctipennis. Its breeding is apparently restricted to limestone springs and the margins of the streams emanating from them in the north central part of the state. An. punctipennis (Say) Biology This species is common in north Florida, rare in central and south Florida. It is more common in the spring and fall. It breeds primarily in the margins of flowing streams and in lime sinks. Females bite during the night or on dark days, seldom in houses. Relationship to disease It is not an important carrier of malaria but it is an efficient vector of dog heartworm. An. quadrimaculatus Say group Biology These four species are distinguishable only by cytological techniques. Classical references to An. quadrimaculatus pertain to the most common species of the group, Species A. This is a large, dark-brown mosquito that breeds in permanent fresh water which contains aquatic vegetation. It is active at dusk and during the night, but becomes a daytime biter during cold weather. Its flight range is less than four miles. This species becomes the dominant Anopheles as one goes north in the state. Relationship to disease This species was the primary vector of malaria in Florida before its eradication, and is still an efficient vector of dog heartworm. An. walkeri Theobald Biology This common dark species is distributed statewide and breeds in fresh water marshes with emergent plants, such as cattails. Females are attracted to humans both during the day and at night but do not generally fly more than a mile from their breeding site. Coquillettidia Cq. perturbans (Walker) Biology This large, black-and-white mosquito is a severe pest in inland Florida. It breeds in established, permanent freshwater marshes containing emergent vegetation where there is a layer of detritus on the marsh bottom. The eggs are laid in a raft on the water surface, and the immature forms attach to the roots of the emergent plants. This aggressive mosquito is active for short periods at dusk and commonly flies three to five miles, often much farther. Females bite both humans and birds. Relationship to disease This species is an important vector of eastern encephalitis to humans throughout the eastern United States, wherever it is associated with Culiseta melanura. Culex Florida has 14 species of Culex that breed in more or less permanent water bodies. Eggs are laid in rafts on the water surface. While breeding is continuous, females can hibernate during the colder months. The biting habits are varied. As a group, female Culex are difficult to separate into species. Often, collectors identify specimens only to subgenus. Some species are important vectors of disease among wild vertebrates.
Synopsis of Florida Mosquitoes 6 Cx. atratus Theobald Biology This small mosquito of the subgenus Melanoconion is widespread in the Keys but less common in the rest of tropical Florida. Little is known of its biology. Cx. bahamensis Dyar & Knab Biology This tropical mosquito is widespread in the Keys and can be found in Dade and Broward counties as well. It breeds in fresh and brackish water. Little is known of its biology. Cx. erraticus (Dyar & Knab) Biology This small mosquito is the most common of the subgenus Melanoconion and is widespread throughout the state. The immatures are found in permanent grassy ponds and swamps, often associated with duckweed, upon which the female lays her eggs. Females feed on birds and humans at dusk and during the day. Cx. iolambdis Dyar Biology This is a subtropical and tropical species of the subgenus Melanoconion that breeds in brackish pools primarily in the Keys. Little is known of its biology. Cx. mulrennani Basham Biology This species of the subgenus Melanoconion is found only in the Keys in water in holes and depressions in limestone formations. Little is know of its biology. Cx. nigripalpus Theobald Biology This is a common mosquito throughout the state and the dominant Culex in the central and southern part of the state during the late summer and fall. This species prefers birds and cattle as hosts but will feed on humans. It breeds in ditches, freshwater marshes and grassy pools. Relationship to disease It is a carrier of St. Louis encephalitis, Venezuelan equine encephalitis and dog heartworm in Florida and can be infected with eastern encephalitis and yellow fever viruses. Cx. opisthopus Komp Biology This small species in the subgenus Melanoconion is widespread, but uncommon, throughout subtropical and tropical Florida. Immatures have been collected from holes of the land crab (Cardisoma guanhumi). Mammals are apparently the preferred hosts, but the species is not considered a pest to humans. Cx. peccator Dyar & Knab Biology This small, rare species in the subgenus Melanoconion is scattered throughout the subtropical and temperate regions of the state. It breeds in grassy pools, almost always associated with Cx. territans. Cx. pilosus (Dyar & Knab) Biology This very small species in the subgenus Melanoconion species is commonly found throughout the state, where it breeds in a variety of temporary freshwater habitats. The eggs are laid singly and can withstand drying out. Reptiles are the preferred hosts in the southern part of the state. Cx. quinquefasciatus Edwards The southern house mosquito Biology This mosquito is common throughout the state and is closely associated with humans. It breeds in a variety of aquatic habitats, including those that are highly polluted with organic matter, such as catch
Synopsis of Florida Mosquitoes 7 basins, sewage treatment ponds, open septic tanks, artificial containers and rain gutters. The species will feed on both birds and humans, and in some areas it will enter houses. Relationship to disease The significance of this species as a pest to humans or vector of St. Louis encephalitis varies by locality both in Florida and throughout the United States. Cx. restuans Theobald Biology This medium-sized species breeds in permanent or temporary pools that contain organic debris. It breeds infrequently in tree holes found at the base of trees. Its distribution is primarily limited to the nontropical regions of the state, where it can be abundant during the winter and spring. It feeds primarily on birds. Cx. salinarius Coquillet Biology This common, medium-sized mosquito breeds in clean freshwater pools, ditches and marshes as well as in brackish water. They bite outdoors and invade houses as well. They can be a major pest to humans during the cooler months, when they are most abundant. Cx. tarsalis Coquillett Biology This western U.S. species is uncommon in Florida and occurs only in the counties west of Interstate 75 and north of Sarasota. It is primarily a bird-feeding mosquito but will feed on humans. It breeds in a variety of permanent aquatic habitats. Relationship to disease In the western United States, this species is the primary vector of western encephalitis to humans and horses. Western encephalitis does not occur in Florida. It can also transmit avian pox virus. Cx. territans Walker Biology This small, dark mosquito has the unusual habit of feeding almost exclusively on amphibians, especially frogs, and not at all on humans. It breeds in grassy pools and ditches containing aquatic vegetation. Culiseta Cs. inornata (Williston) Biology This is a large mosquito with white "shoulders." It breeds in open grassy ditches and marshes. It lays its eggs in a rounded raft. While uncommon, it is found throughout the state. The adults are active only during the cooler months, aestivating during the summer. It rarely feeds on man, preferring birds, cattle and horses. Cs. melanura (Coquillett) Biology This medium-sized mosquito breeds in permanent wooded swamps in the interior of the state. The egg raft is irregularly rounded and usually is laid on the water surface near the roots of trees within swamps with muck-peat soils. The larvae prefer the cavities within the root system of the tree. This species feeds almost exclusively on birds. Relationship to disease Cs. melanura is an indicator species for eastern encephalitis. Eastern encephalitis can occur only where this species is present. It is also the primary vector among birds. Deinocerites De. cancer Theobald The crabhole mosquito Biology This mosquito breeds primarily in holes made by the land crab Cardisoma guanhumi in the eastern and southern coastal salt marshes or nearby freshwater. It
Synopsis of Florida Mosquitoes 8 is fairly common in the south but it rarely bites humans. Mansonia Ma. dyari Belkin, Heinemann & Page Biology This species is often common wherever water lettuce occurs. The egg masses are attached to water lettuce leaves and, after hatching, the larvae and pupae attach permanently to the roots, getting their oxygen from the plant tissues. The males bite humans but seldom become pests. Relationship to disease In Panama this species is a major vector of St. Louis encephalitis. Its relationship to St. Louis encephalitis virus in Florida is unknown. Ma. titillans (Walker) Biology This tropical species is found only in the southern half of the state, where it breeds on a variety of floating plants, especially water hyacinth. The egg masses are laid on the underside of floating leaves, and the larvae and pupae attach to, and derive their oxygen from, the roots. It can be a pest to humans near its breeding sites. Relationship to disease In South America this species is a major vector of Venezuelan encephalitis. Orthopodomyia Or. alba Baker Biology This rare, medium-sized species breeds in tree holes and artificial containers in the northwestern part of the state. It is usually associated with the more common Or. signifera. It does not bite humans. The adults of this genus are easily recognized by the fine, longitudinal lines of silvery scales on the thorax. Or. signifera (Coquillett) Biology This species is widespread and not uncommon throughout Florida. It does not bite humans, but may bite birds or amphibians. The larvae live in tree-hole water with a pH of 7.6 to 8.4. The adults of this genus are easily recognized by the fine longitudinal lines of silvery scales on the thorax. Psorophora Most of the 10 species of Florida Psorophora are severe biters and several are major pests of humans and livestock. Two species are actually beneficial because the larvae are predaceous on other mosquito larvae. The eggs of most Psorophora are laid singly on damp soil in freshwater areas that flood periodically. Many species produce a brood whenever the eggs are flooded. Therefore, nuisance problems are closely associated with rainfall or irrigation. The eggs can lay dormant for several years, but when they hatch the larvae develop very rapidly. The adults are strong fliers and can move considerable distances. Ps. ciliata (Fabricius) The shaggy-legged gallinipper Biology This very large mosquito has very shaggy legs and breeds in rain pools, grassy ditches and depressions statewide. The larvae are predaceous on other mosquitoes. The adults are severe biters, often alarming people because of their large size. This species is very similar to Ps. howardii. Ps. columbiae (Dyar & Knab) The Florida glades mosquito Biology This black mosquito, above average in size, breeds in a variety of temporary water situations throughout Florida including woodland pools, pastures and grassy ditches. The females can appear in enormous clouds and be a major pest at night up to five miles or so from the breeding site. The adults are not long-lived so the problem abates rapidly.
Synopsis of Florida Mosquitoes 9 Ps. cyanescens (Coquillett) Biology This rare, blue-black mosquito is found only in the northwest part of the state. The females are annoying daytime biters and may make a peculiar high-pitched sound. Ps. discolor (Coquillett) Biology This species is uncommon and found only in the Panhandle and extreme north Florida. The larvae remain submerged most of the time and require about 10 days to complete development. They are fierce biters. Ps. ferox (Von Humboldt) The white-footed woodland mosquito Biology This common, blue-black, midsize mosquito is easily recognized by its white "feet." It breeds in woodland pools and adjacent ditches. They can be a nuisance to humans and animals in the woods, day or night. Ps. horrida (Dyar & Knab) Biology This species is rare in Florida. It is similar to Ps. ferox and will bite humans in wooded areas. Little is known of its biology. Ps. howardii Coquillea The Howard's gallinipper Biology This species is similar to Ps. ciliata in most respects. This very large mosquito has shaggy legs and breeds in rain pools, grassy ditches and depressions statewide. The larvae are predaceous on other mosquitoes and the adults are severe biters, which can alarm people due to their large size. They are known to be long-distance fliers. Ps. johnstonii (Grabham) Biology This tropical mosquito is found only in the Keys. It breeds in temporary fresh rainwater pools, and is a very aggressive biter, day or night, in shade or sun. Ps. mathesoni Belkin & Hogue Biology This rare, woodland mosquito is found only in the Panhandle and extreme north Florida; often associated with Ps. ferox. Ps. pygmaea (Theobald) Biology This is a small, tropical mosquito found only in eastern and southern counties south of Daytona Beach. Very little is known of its biology. Toxorhynchites Tx. rutilus (Coquillett) Biology The larvae of this very large iridescent mosquito are predators on other mosquitoes found in the tree holes and artificial containers where they breed. The larval period can last up to six months and this species has been used to control Ae. aegypti and Ae. albopictus larvae. The adults do not feed on blood. There are two subspecies, Tx. rutilus rutilus and Tx. rutilus septentrionalis, which differ only in the color of the adults. Uranotaenia Ur. lowii Theobald Biology This small mosquito breeds in permanent grassy aquatic habitats and can be locally numerous. They do not feed on humans and probably feed on cold-blooded animals.
Synopsis of Florida Mosquitoes 10 Ur. sapphirina (Osten Sacken) Biology This is the larger of the two Uranotaenia and is distinguished by a line of brilliant blue scales on the thorax. These small mosquitoes breed in permanent grassy aquatic habitats and can be locally numerous and move several miles from their breeding sites. They do not feed on humans and probably feed on cold-blooded animals. Wyeomyia Wy. haynei Dodge Biology This small species is found in pitcher plants only in north Florida west of the Apalachicola River. Wy. mitchellii (Theobald) Biology The larvae of this species are found in leaf axils of bromeliads. They bite humans and can be a nuisance during the day in humid woodlands or yards. They breed continuously but they occur only in the southern two-thirds of the peninsula. This species of Wyeomyia prefers bromeliads in shaded locations and is more abundant inland. Wy. vanduzeei (Dyar & Knab) Biology The larvae of this species are found in leaves of bromeliads. They bite humans and can be a nuisance during the day in humid woodlands or yards. They breed continuously but occur only in the southern two-thirds of the peninsula. This species of Wyeomyia prefers bromeliads in more sunny locations and is more abundant in coastal areas.