[b]Save Florida's Native Bromeliads
Florida has 16 species of native bromeliads, many of which are restricted to the southern portion of our state. Florida is at risk of losing some of its most unique plants foerver, as an invasive, exotic pest weevil (Metamasuis callizona) is destroying populations of five of these native bromeliad species at an alarming rate. Six additional species of rarer bromeliads are also vulnerable.
The weevil entered Florida in a shipment of bromeliads from Mexico, and by the time it was discovered in a nursery in 1989, it had become established in Broward County. It is now found in sixteen counties in south Florida and is fast approaching Florida's most rare, endangered bromeliad populations in the Everglades.
The Mexican bromeliad weevil kills the plants through the tunneling of its immature stage (larve), which eats out the entire base of the plant, causing it to fall from the tree that supports it.
The weevil prefers large, mature plants, and the death of many of the breeding individuals quickly wipes out entire populations. Two species of once-abundant bromeliads (Tillandsia utriculata and Tillandsia fasciculata) have been placed on the state's list of endangered plant species as a direct result of destruction from the weevil.
The 'Save Florida's Native Bromeliads' project is an attempt by the Florida Council of Bromeliad Socorties, the University of Florida, and the Florida Department of Ageiculture and Consumer Services (Division of Plant Industry) to manage the weevil and conserve the bromeliad species at risk before the weevil is able to completely destroy them. The project's goals include both the immediate reduction in the damage being done by the weevil and the long-term protection of Florida's native bromeliad populations.
The candidate biological control agent is a specialist parasitic fly from Honduras that attacks the immature stage of the weevil while in its tunnel. The fly will be maintained in a quarantine facility until non-target tests are compleated to ensure that it will only affect the pest weevil.
*Collection of seeds of bromeliad species at risk:
Seeds from bromeliad species threatened by the weevil have been collected from parks and natural areas throught south Florida. They have been germinated by volunteer nursery growers, and the resulting plants will eventually be reintroduced to their respective places of collection once weevil populations are managed.
The ultimate success of the project requires greater public understanding of the problem and support for its solution. Educational materials will be provided to Florida Parks Service personel and members of the state's 12 bromeliad societies for their use in educational programs and will offer additional resources for teachers and the public to futher the appreciation of these endangered plants.
Immigration of the Mexican Bromeliad Weevil
The Mexican bromeliad weevil immigrated to Florida on a shipment of bromeliads in the late 1980's. Examination of plant inspection records at ports in Florida shows how that was possible. Between 1979 and 1990, USDA-APHIS plant inspectors in Florida intercepted 141 shipments of bromeliads (mostly Tillandsia spp.) that contained Metamasuis spp. weevils. Of the interceptions of those identified to the species level (122 were for unidentified Metamasius), three shipments contained Metamasuis quadrilineatus ( from Costa Rica, Guatemala and Mexico). The remaining 14 interceptions were of the weevil that is destroying Florida's bromeliads, Metamasuis callizona. All interceptions of Metemasius callizona were in shipments of bromeliads from Mexico. Additionally in recent years, two specimens of Metamasuis flavopictus have been found by Florida nurseries importing bromeliads from Guatemala. Since less than 2% of imported plant shipments are inspected, and it is very difficult to detect eggs or small larvae deep within the plants, there is ample opportunity for infested plants to be overlooked.
All it takes is one infested plant to escape detection, and the Mexican bromeliad weevil apparently arrived that way. In a Fort Lauderdale (Broward County) mursery in 1989, plant inspectors from the Florida Department of Agriculture and Consumer Services found several of these weevils on Tillindsia ionantha, a bromeliad from Mexico and Central America. The likely origin of the shipment was a bromeliad grower in Veracruz, Mexico. The Fort Lauderdale nursery was treated with pesticides, but by the time the weevil was detected, it had become established in the surrounding area. Since then, it has been found in seventeen counties.
Human transportation of plants has contributed to the threat to Florida's bromeliad populations. The situation could be exacerbated at any time in the future if related bromeliad pests enter the state, a scenario that is not unlikely given the high number of insect species that have entered Florida undetected and given that there are over 20 bromeliad-attacking weevils in the neotropical countries from which so many ornamental plants are imported. Most bromeliad weevils are species of Metamasuis. The species most likely to enter and become established in Florida, based on interception records, are Metamasuis quadrilineatus and Metamasuis sellatus.
To avoidf futher threats to Florida's native bromeliad species, bromeliad importers are encouraged to apply a pesticide dip to imported bromeliads, especially those received from Mexico and Central America. However, pesticides may not kill weevil eggs. Therefore, importation of seed rather than plants would be the most effective means of preventing infestations of related weevils.
Finally, if you buy bromeliads as ornamental plants fro your home, consider purchasing from a nursery that grows native bromeliads.
Bromeliads (family Bromeliaceae) are a large group of plants (over 2,500 described species) of neotropical origin. They are a conspicuous part of the flora of South and Central America and the West Indies. Only a few bromeliad species are native to penninsular Florida, and still fewer range north and west into other states. In South America, bromeliads have evolved to occupy a wide range of habitats from humid lowlands to deserts to high mountains. They grow in humus or sand on the ground, on rocks, or as epiphytes on trees. Some of them are grown as crops (pineapple), and many are grown as ornamentals, and for this reason bromeliads are now grown in the tropics and subtropics worldwide. In more temperate climates they are grown in glasshouses.
Bromeliads considered as native to Florida belong to three genera (Catopsis, Guzmania, and Tillandsia) and all of them are epiphytic. The three native species of Catopsis and one Guzmania are restricted in Florida to the extreme south, where all of them are listed as endangered. Most of the dozen native species of Tillandsia have quite restricted distributions; four (Tillandsia fasciculata, Tillandsia flexuosa, Tillandsia pruinosa, and Tillandsia utriculata) are listed as endangered, and two (Tillandsia balbisiana, and Tillandsia variabilis) as threatened.
They are the most common native examples of tank bromeliads that harbor mosquito larvae. The endangered, threatened and commercially exploited plants are protected under Florida law and to a lesser extent under U.S. law. The remaining two species, which are not protected, are "Spanish moss" (Tillandsia usneoides) and "ball moss" (Tillandsia recurvata); these are the most common native examples of bromeliads that do not form tanks and therefore do not harbor mosquito larvae.
Many nurseries in South Florida sell bromeliads and a few nurseries specialize in bromeliads. They sell natural species, cultivars, interspecific hybrids, and even intergeneric hybrids with such names as Neomea 'popcorn.' Bromeliad cultivation has become so popular that a society, "The Bromeliad Society International" (BSI), which publishes the Journal of the Bromeliad Society, formerly Bulletin of the Bromeliad Society, was formed in 1951. There are now 13 local bromeliad societies in Florida alone, some of which publish newsletters such as The Bromeliadvisory (from the Bromeliad Society of South Florida), The Caloosahatchee Meristem (from the Caloosahatchee Bromeliad Society), and The Commentary (from the Bromeliad Society of Broward County).
Biology of Bromeliads
Bromeliads are monocotyledonous plants that share biological characteristics of related families such as Cannaceae and Musaceae. Although a few members of some plant families other than bromeliads (e.g. Agavaceae, Araceae, Cannaceae, Marantaceae, Musaceae, Strelitziaceae) accumulate little tanks of water in their leaf axils, hundreds of species of bromeliads have this characteristic. The arrangement of these tanks varies; in some species water accumulates in a few or in many seperate leaf axils, while in others the central leaves together form a large tank surrounded by a few, separated tanks provided by outer leaf axils. Bromeliad leaves bear special epidermal cellular structures (trichomes) that absorb water and minerals from the leaf surface. This ability to absorb from the leaf surface explains why some bromeliads (sometimes called "air plants") can live with their roots attached to telephone lines and power poles. These air plants gain their nutrients from whatever mineral particles, blown about in the wind and rain, happen to land on their leaf surfaces. They seem to "live on air," and their feeble-looking roots serve merely to anchor them.
Most cultivated bromeliads are epiphytic and thus have a natural association with trees. During and after rains, water dripping from trees is no longer just rainwater, but is enriched with minerals leached from tree leaves.; bromeliads absorb it through trichomes on their leaf surfaces or through through trichomes on the leaf surfaces forming their tanks. The tanks also trap pollen, dead leaves, twigs and seeds falling from the trees; these materials break down in the tanks to form a nutritive soup available to the bromeliads and mosquito larvae.