Frank and McCoy (1992) listed 271 species of insects that immigrated into Florida; 209 were first collected in Florida after 1970. In a later publication, Frank and McCoy (1993) listed another 351 insect species that were introduced into Florida after 1980 for potential biological control agents. Their lists contained species from published and unpublished records and indicated that 154 insects had been released, almost all of them (151) as biological control agents against insect pests and nuisance plants.
Florida is susceptible to invasions by exotic species through immigration and colonization. Clark et al. (1967) discussed the ecology of insect populations in theory and in practice. Other insects were purposely introduced to control nuisance species (Frank and McCoy 1990).
Frank and McCoy (1992) summarized the literature since 1970 that identified 271 exotic insects in Florida. The authors concluded that about 20 recent immigrants are or could become major pests in Florida (Table 6). At least 8% of the species seem to have arrived as stowaways, and many actual or potential major pests are among them. Thirteen orders of insects are represented in the tabulation. Immigrant species are not equitably distributed among orders or among families. To tabulate the immigrants, the authors searched published records and then verified the records by consulting authorities on the taxa. The authors are certain they produced a reasonably thorough tabulation but could not guarantee its completeness. They chose in advance to exclude four kinds of records from their tabulation: introductions they included in their later publication (Frank and McCoy 1993) to make their task manageable; records that were published before 1971; records of species that are native north of Mexico in North America, even if that part of their range was small; and records of species they called "taxonomic immigrants," which are species that were introduced in Florida because of improper identification. Examples of the second kind of record are two moths, Eulipidotis metamorpha Dyar and Metalectra geminicincta Schaus, that were reported in 1991 as new to Florida (Dickel 1991) and would have been included in the tabulation had they not been reported before 1971. An example of the third kind of report is an ant, Pseudomyrmex mexicanus Roger, found ca. 1960 (Whitcomb et al. 1972) that would have been included in the tabulation if Texas had not been part of its native range. The authors concluded that all or almost all of the 70 species of immigrant insects reported from northeastern North America by Hoebeke & Wheeler (1983) entered the continent as stowaways. The list of reported immigrant insects in Florida (Table 6) revealed that species arrived as stowaways and by other means such as flight, wind dispersal, or rafting. One identification of nonindigenous insects is by the assumption that all recorded immigrant species in Florida whose names are on the U.S. Department of Agriculture list of interceptions arrived in Florida as stowaways. Insects that were discovered on imported plants and plant materials at U.S. seaports and airports by USDA-Animal and Plant Health Inspection Service inspectors are treated as pests and are recorded and destroyed. This is done under the Plant Quarantine Act of 1917 (7 U.S. Code 151 et seq.) and the Federal Plant Pest Act of 1939 (7 U.S. Code 150aa et seq.) to protect agriculture, horticulture, and other human interests from damage by exotic insects (Sailer 1978, 1983). USDA-Animal and Plant Health Inspection Service publishes an annual list of insects the entries into the United States of which were intercepted. Frank and McCoy (1992) made the described assumption with the fiscal-year-1980 list of more than 18,000 interceptions (PITSS 1982) and annotated their list of immigrant insects accordingly with the letters "PS" to indicate potential stowaways (Frank and McCoy 1992).
To determine which insects on on their lists (Frank and McCoy 1992,1993) where aquatic, we asked D. J. Howard Frank to assist us with the identification of the aquatic insects, insects with a life stage that depends on water, or insects with close associations with aquatic or semi-aquatic environments. We used tables from Frank and McCoy (1992 and 1993) for the identifications. Much of the information on dates of original captures and countries of origin in this section was obtained from Frank and McCoy (1992, 1993).
Coleoptera:Chrysomelidae
Microtheca ochroloma Stal. This beetle was first intercepted in New Orleans by inspectors of the Bureau of Entomology and Plant Quarantine; it was on grapes from Argentina (Chamberlin and Tippins 1948). A survey by Chamberlin and Tippins (1948) in early April 1947 of the newly discovered chrysomelid revealed that the beetle is distributed in the city limits of Mobile, Alabama, and in a considerable surrounding territory in Mobile County. The species feeds on cabbage, collards, mustard, turnips, and radishes. In 1972, it was on watercress at an Alabama nursery (Woodruff 1974), and it is now established in Alabama. Frank and McCoy (1991) reported that this species has immigrated into Florida, but give no additional details. It is native to South America (Woodruff 1974) and a serious pest of crucifers in Argentina and Uruguay (H. L. Parker, Research Entomologist, Bureau of Entomology and Plant Quarantine, U.S. Department of Agriculture, unpublished records).
Diptera:Chironomidae
Goeldichironomous amazonicus (Fittkau). This midge was found in 1977 and reported under the name Siolimyia amazonica Fittkau. It is native to the Bahamas, Central America, or South America and was probably brought to Florida as eggs or larvae on aquarium plants or on other aquatic plants (Wirth 1979).
A mass emergence of this aquatic midge was reported in August 1977 from near a small canal in a residential area in Kendall, Dade County, Florida. The species previously was known only from Brazil, Nicaragua, and Peru. Additional records are reported from the Bahamas, Mexico, and the Panama Canal Zone. On Lake Nicaragua, mass emergences of this species, called "Sayule" by the local people, are serious nuisances. Whether the species occurs naturally in tropical Florida or was recently introduced by commerce is unknown; if it was recently introduced, it may become a pest species (Wirth 1979).
Because of its recorded presence in the Bahamas, the species may occur naturally in the tropical parts of extreme southern Florida, perhaps varying in abundance with climatic cycles of temperature (Wirth 1979). However, if the Kendall population represents a recent introduction, the species may have arrived by air transport or in shipments of tropical fishes or fish food, and its abundance may increase to a population level and distribution that would class it as a nuisance species. In either case and because of its unusual biological characteristics, the species should be carefully studied by limnologists and by pest abatement agencies in southern Florida (Wirth 1979). The abundance of eutrophic shallow lakes and canals in southern Florida probably provides habitats that can support populations of this species at severe nuisance levels (Wirth 1979).
Diptera:Culiciadae
Aedes albopictus (Skuse). This mosquito was found in 1986 in Florida. It is probably from Japan and entered Florida from Texas (Craig 1993). Rai (1991) discussed the movement and status of Aedes albopictus in the Americas. The common name "Asian tiger mosquito" was given it by Peacock et al. (1988). In 1986, this species was at a waste-tire site in Jacksonville (Craven et al. 1988; Peacock et al. 1988). Hughes and Porter (1956) discussed the dispersal methods of mosquitoes during the larval stage. State-wide surveillance of A. albopictus (Skuse) was initiated in 1986 by the Entomology Services of the Florida Department of Health and Rehabilitative Services and by local mosquito control agencies (Smith et al. 1990). By the end of 1989, this exotic mosquito had been found exclusively in cemeteries of 11 of the 67 Florida counties (Smith et al. 1990). In a survey of this insect in Florida during 1990, it was detected in 40 more of 46 Florida counties. The search was initially focused near counties that were known to have populations of this species. Collections were made at tire and auto-repair shops, county landfills, illegal tire piles, and cemeteries (O'Meara et al. 1992). Most recent surveys by O'Meara et al. (1992) revealed this species in 53 of the 67 Florida counties. At several locations, it has become well-established in cemeteries before appearing in nearby accumulations of waste tires. The recycling of plastic floral baskets may be aiding the spread of this species. Mosquitoes were commonly in all types of flower-holding containers in cemeteries, except in bronze vases. In the laboratory, most A. aegypti eggs that were laid in bronze vases hatched, but larvae subsequently died. The spread of A. albopictus in cemeteries seems to occur at the expense of A. aegypti populations. At one cemetery, immature A. albopictus and A. aegypti were in about 70% of the containers with Aedes at the start of monitoring. In subsequent collections from this site, A. albopictus was in nearly all containers with Aedes but progressively decreased in containers with A. aegypti. This trend did not seem to be due to a seasonal pattern because in a nearby cemetery where A. albopictus was absent, A. aegypti did not show a similar decline. Limiting flower-holding containers to those with drain holes or to bronze vases would greatly limit mosquito production (O'Meara et al. 1992). Various types of micro- and macrohabitats make cemeteries ideal locations for investigating the environmental factors of the distribution and abundance of resident and exotic mosquitoes that inhabit containers (Schultz 1989).
Aedes albopictus was probably introduced into North America through the importation of used tires from Japan or Taiwan. During the 1980's, the number of imported used tires in the United States from countries where A. albopictus is indigenous increased. Most imported used tires arrived in containers that were not adequately inspected for mosquitoes at the ports of entry. Imported tires were sent to numerous locations where they were stored outdoors. Those that were not suitable for recapping ended up at illegal dump sites, and consequently A. albopictus became well-established in the United States. To date, A. albopictus has been detected in 22 states including Hawaii.
In Florida, A. albopictus is widely but sparsely distributed in the central part of the state, and it is rare in southern Florida. It will probably continue to expand its range down the Florida peninsula and become a common inhabitant of containers statewide. Although immature A. albopictus inhabit many different types of containers, scrap tires harbor this mosquito more frequently and in greater numbers than any other type of container. Other common anthropogenic habitats for immature A. albopictus include bird baths, water bowls for pets, buckets, plates under potted plants, clogged rain gutters, and flower vases. Natural containers, such as treeholes and tank bromeliads, also provide suitable habitats for immature A. albopictus. Indeed, this mosquito shows a much greater propensity than A. aegypti for using natural containers. This species is generally distributed across the northern portion of the state; more recent findings in Polk County suggested a southern spread. Dispersal of A. albopictus almost can be predicted by following used tire movement and storage (Smith et al. 1990).
Since the initial report of records in Duval and Escambia counties (Peacock et al. 1988), A. albopictus has been found in 28 more tire yards, in residential sites in Jacksonville (Duval County), and in five tire yards in the Pensacola area (Escambia County). Some of the new sites in Pensacola received tires from Mobile, Alabama, a city that is infested with the Asian tiger mosquito (Aldes albopictus). Another site of special interest is the Jacksonville Naval Air Station where shipment to new areas and countries is possible (Smith et al. 1990).
The Polk County (Polk City) record was from the state's largest known tire yard. An estimated 5 million tires occupy this site. Since the discovery in May 1989, two more tire yards with Aedes have been identified in this county; one was about 8 km south in Winter Haven and the other about 1.6 km south of Mulberry. These sites are east of the Tampa Bay area and represent the known southeastern limit of the A. albopictus distribution in the United States (Smith et al. 1990).
Thus far, only one adult female was collected from St. Johns County, and the primary source has not been located. The Clay County record was unique because it was from a site without nearby tires. That collection was made by military personnel who collected larvae from a cemetery site during field vector surveillance training (Smith et al. 1990).
Aedes albopictus has quickly become a serious pest species in many northern Florida communities where the annoyance level of this species is greater than that of A. aegypti populations (Smith et al. 1990, O'Meara and Gettmann 1991). A wider range of habitats tends to make A. albopictus more common than A. aegypti. Moreover, Florida populations of A. albopictus were probably derived from temperate zone stock that may be better adapted to northern Florida than A. aegypti that is primarily a tropical and subtropical mosquito.
The best approach for controlling A. albopictus (and A. aegypti) is the elimination of larval habitats. Control of A. albopictus in Florida continues to rely on monitoring the spread of the mosquito, public education, and the encouragement of source reduction (Smith et al 1990). The Solid Waste Disposal Act (1965; 42 U.S. Code 3251-3259) created regulation of waste-tire storage and disposal in Florida. If properly enforced, these rules should limit the production and spread of mosquitoes that breed in tires (Smith et al 1990).
Aedes bahamensis Berlin
This mosquito is native to the Bahamas (Pafume et al. 1988). It is now well-established in southern Florida, where it is widely distributed in urban and rural areas throughout Dade and southern Broward counties east of the Everglades. When discarded automobile tires were sampled in areas near human habitation, larvae and pupae of A. bahamensis were frequently in association with immature A. aegypti. Elsewhere, however, A. bahamensis generally occurred in the absence of A. aegypti. The persistence of A. bahamensis populations at specific sites was documented in egg collections from ovitraps and in larval samples from the water in discarded tires (O'Meara et al. 1989).
In southern Florida, Aedes bahamensis was initially discovered during fall 1986 in collections from light traps baited with dry ice and from ovitraps. Ironically, these ovitraps were used to evaluate the spread of another exotic mosquito, Aedes albopictus (Skuse) (Pafume et al. 1988). The establishment of A. bahamensis in southern Florida may have significant consequences for A. aegypti that in recent years has been a common domestic mosquito in this region. Here, A. aegypti larvae were most frequently in scrap tires that are improperly stored or illegally dumped (Frank 1981). O'Meara et al. (1989) investigated the current distribution of A. bahamensis and its association with A. aegypti by sampling for these mosquitoes in and around areas with discarded tires.
Immature forms of the mosquito were in sites with discarded tires or occasionally in sites with other types of artificial containers at 37 locations. At many of these sites (n = 20), A. bahamensis was found in association with A. aegypti. The two species occurred together over a wide range of habitats, including residential, commercial, and industrial zones of the city and in undeveloped or sparsely developed rural areas near human habitation.
Adult A. bahamensis are generally inactive during the daytime until about 1 or 2 hours before sunset. Flight and blood-seeking continue after sunset for at least a few hours. In contrast, A. aegypti is diurnal with two peaks of activity, one in midmorning and the other in the afternoon. These differences in daily activity patterns should be detected in any assessment of the relative pest status of A. bahamensis (O'Meara et al.1989).
(Aedes aegypti; L.) - Yellow Fever Mosquito. This mosquito was established in the United States before 1970. It is native to Africa, arrived in the United States before 1850, and is a serious pest species (Skiles 1989). The history of the attempted eradication of this mosquito is inseparable from the history of anthropogenic attempts to control yellow fever, a viral disease for which this species is the primary vector in human populations (Skiles 1989). It is, however, also the primary vector of the viral disease dengue and is a demonstrated or suspected vector of several other diseases of humans and animals (Skiles 1989). Skiles (1989) discussed the life history of this species and the futile efforts to eradicate it from many parts of the world. In the Western Hemisphere, this mosquito breeds in water that collected in anthropogenic containers of almost any kind inside houses and out-of-doors. They include containers for water collection or storage (cisterns, flower pots, water jugs, animal watering trough), discarded containers (pots, cans, bottles, auto tires, auto bodies, drums), masonry defects, and neglected containers (gutters, drain traps, unused toilets; Skiles 1989). Water in abandoned or infrequently used boats can also serve as a breeding place.
Frank (1981) discussed the role that discarded tires have had in the survival and the spread of A. aegypti. Larvae occur throughout the year in southern Florida, although breeding may stop during the coldest weeks. In Florida as in Puerto Rico, populations increase during the hotter, wetter months and have a clear seasonal life cycle. In Puerto Rico in 1973-1976, dengue cases correlated with monthly prevalence of larvae.
Because adults usually stay within a few hundred meters of their larval sites, long-range dispersal of the species depends primarily on humans. As a result, A. aegypti moves along human travel and trade routes and is particularly prevalent along coastal areas and harbors. The abundance of bilge water and the necessity of transporting fresh water on ships ensures species dispersal along shipping routes. Tonn et al. (1982) reported that almost every month at least one ship that enters Panamanian ports is infested with A. aegypti. Hence eradication alone is not sufficient to ensure freedom from infestation in a given locality. Continual surveillance is required to guard against reintroduction. Aedes aegypti was probably a forest species that bred in tree holes and in other natural water containers, as it often does in Africa today. But, as Tonn et al. (1982) noted with concern, occasional breeding of A. aegyptic in natural containers such as tree and rock holes is reported from many countries. Schliessmann (1967) reported that even in the United States, larvae were occasionally in tree holes and in leaf axils of bromeliads (Family Bromeliaceae) and of travelers' palms (Family Phoenicaceae).
The United States attempted to eradicate A. aegypti with DDT in 1964 and ceased operations in 1968. Although the hemisphere-wide eradication of yellon fever and A. aegypti is desirable, Schliessmann and Calheiros (1974) considered that their elimination as probably impossible for many reasons including the costs associated with its extermination. The attempted eradication of A. aegypti, despite the new control equipment and insecticides and millions of dollars annually has not been successful (Tonn et al. 1982).
Lepidoptera:Pyralidae
Parapoynx diminutalis Snellen. This moth was in Florida in 1976 on hydrilla. It is native to Asia (Del Fosse et al. 1976) and seemingly immigrated to Florida on hydrilla. Its feeding occasionally causes heavy defoliation of the host plant. This insect was found during constructions of plastic pools (3.05 m diam, 0.8 m deep) for herbicide-testing experiments on hydrilla by technicians of the U.S. Department of Agriculture at the Fort Lauderdale Agricultural Research Center. The workers who found the species reported that the worms were eating the plants. On examination of the plants, several small pyralid caterpillars and adult pyralids were noted. John Heppner of the Department of Entomology, University of Florida, Gainesville, identified some of the specimens as the common pyralid Parapoynx allionealis Walker, but most were P. diminutalis (Snellen) heretofore known only from Pakistan to Southeast Asia (Del Fosse et al. 1976). How or when this species was introduced are not known. The larvae caused considerable damage to hydrilla. The use of this insect was later rejected by researchers at the Fort Lauderdale Agricultural Research Center because of its broad host range in Asia and Florida. It seemingly prefers hydrilla (Buckingham and Habeck 1990; Buckingham and Bennett 1989; Center et al. 1991).
Odonata:Aeshnidae
Coryphaeschna adnexa (Hagen). Blue-Faced Darner. This insect was first discovered in southeastern Florida in 1980. Its range is south through the Greater Antilles and from northern Mexico to Argentina. Its habitat is weedy lakes, canals, and marshes. It flies all year in the tropics and commonly feeds over lawns and in clearings (Dunkle 1989).
Odonata:Lestidae
Lestes spumarius (Hagen in Selys) - Antillan Spreadwing. This spreadwing was found in Florida in 1988 and is from Cuba or the Bahamas (Dunkle 1990).
Odonata:Libellulidae
Crocothemis servilia - Scarlet Skimmer. This species is native to Asia and was found in Florida in 1975. Since August 1977, it has been established in a canal near Goulds, Dade County, Florida. Males, females, and young were collected (Paulson 1978; Begum et al. 1985).
Erythemis plebeja (Burmeister)-Black Pond Hawk. This species was first discovered in Miami, Florida, in 1971 and was common. It has spread sparingly north from Cuba or from the Bahamas to Orlando and occurs in southern Texas south to Paraguay and the Great Antilles. It flies all year near its preferred habitat of quiet waters such as ponds, lakes, canals, and slow rivers (Dunkle 1989).
Micrathyria aequalis (Hagen) - Spottailed Skimmer. This species was first discovered in the Miami area in 1985 (Dunkle 1989). It is uncommon and has not spread farther. This species occurs from southern Texas to Ecuador and in the West Indies. It flies all year in its normal habitats of permanent and temporary ponds, lakes, and sloughs. May (1980) studied this species.
Micrathyria didyma (Selys in Sagra) - Three-Striped Skimmer. This insect was first found in the Miami area in 1985. It is uncommon in southern Florida and has not spread farther. It is also in the Bahamas and West Indies and from northern Mexico to Ecuador. Its habitat is shady ponds and canals, and the species flies all year (Dunkle 1989).
