Tillandsia stricta, illustration by Margaret Mee, Smithsonian InstitutionSave Florida's Native Bromeliads, Immigration of the Mexican bromeliad weevil
 
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Above illustration,
"Tillandsia stricta,"
by Margaret Mee,
© Smithsonian Institution,
used with permission.
   

The Mexican bromeliad weevil immigrated to Florida on a shipment of bromeliads in the late 1980s. 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 Metamasius spp. weevils. Of the interceptions of those identified to the species level (122 were for unidentified Metamasius), three shipments contained Metamasius quadrilineatus (from Costa Rica, Guatemala and Mexico) and one contained Metamasius sellatus (from Mexico). The remaining 14 interceptions were of the weevil that is destroying Florida's bromeliads, Metamasius callizona. All interceptions of Metamasius callizona were in shipments of bromeliads from Mexico. Additionally in recent years, two specimens of Metamasius 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 in that way. In a Fort Lauderdale (Broward County) nursery in 1989, plant inspectors from the Florida Department of Agriculture and Consumer Services found several of these weevils on Tillandsia 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 17 counties and is rapidly approaching populations of the state's rarest bromeliads in the Everglades region.

 

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 (see Invasive Exotic Species) 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 Metamasius. The species most likely to enter and become established in Florida, based on interception records, are Metamasius quadrilineatus and Metamasius sellatus.

 

To avoid further 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 for your home, consider purchasing from a nursery that grows native bromeliads.