Updated by Faith T. Campbell in July 2026
NOTE: this pest is not known to spread in or on firewood. It is included in the Gallery of Pests for general information purposes only.
The Mexican bromeliad weevil (Metamasius callizona) is native to southern Mexico, Guatemala (Frank and Thomas 1994; Frank and Cave 2005), and Belize (Cooper, Cave and Frank 2023). It was detected in a nursery in Ft. Lauderdale, Broward County, Florida in 1989 and likely came on a shipment of ornamental bromeliads from Mexico. The nursery treated the infested plants, but the weevil had already established on native bromeliad species in the natural environment. By 1991, it was detected in four counties in southern Florida; by 1999, it was found in 12 more. It is now in most counties of peninsular Florida from Daytona (Volusa County) south to Miami-Dade (Patrick Gordon, Florida Department of Agriculture and Consumer Services, pers. comm. June 2026).
Florida has 16 native species of bromeliads. Before arrival of the Mexican weevil, eight were listed as threatened or endangered in the state (Frank and Cave 2005). The Florida Endangered Plant Advisory Council added two species that host M. callizona – Tillandsia utriculata and Tillandsia fasciculata – to the endangered list under the 1998 Florida Administrative Code.
Twelve species are believed to be vulnerable to the weevil. Of the two species newly listed as endangered, T. utriculata is at most immediate risk. T. fasciculata is expected to decline over a longer period.
Populations of T. utriculata were very wide-spread throughout central and south Florida. Some populations were “giant” and dense, containing very large mature plants and producing large numbers of seed output. The species had a major influence on biological cycles in the forests where it was present. Up to 15 invertebrates depend on bromeliads, especially the water that collects at the bases of the leaves. Several of the species that inhabit the water pooled in T. utriculata’s base are endemic to Florida, so their loss in not just a local loss, but global extinction (T.M. Cooper personal communication, June 2026). See Frank (1983) and Frank and Fish (2008) for more information about bromeliads’ ecological importance.
Contrast re: impact on two species, T. utriculata and T. fasciculate
T. utriculata is attacked preferentially. Possible factors are that its leaves are softer and its large, nutrient-dense (for a bromeliad) stems can support many weevil larvae. Often the first signs of infestation was the center falling out of the plant (Cooper 2008). T.M. Cooper suggests that the real threat comes from the combination of plant’s very slow reproduction and weevil’s rapid attack. T. utriculata does not produce seed for up to 20 years. Furthermore, an extremely small fraction of the approximately 10,000 seeds released by a mature plant make it to reproductive age. Thus, a plant that required 18 years to begin growing an inflorescence, which then takes roughly a year to flower and produce seed, can be killed by a weevil within a few months. Also T. utriculata is monocarpic (it doesn’t produce offshoots). T.M. Cooper asserts that if the bromeliad weevil extirpates T. utriculata from Florida, it will not be because the weevil ate the very last plant, it will be because T. utriculata seed output has fallen below a sustainable level.
The other endangered species, T. fasciculata, has several advantages – although it remains very much in danger of being extirpated. It has tougher leaves, smaller stems, and is polycarpic (it produces both seed and offshoots). A large T. fasciculata plant can sprout up to a dozen blooming rametes at a time. If the weevil kills one, other rametes will bloom and seed. At the same time, it might produce numerous up to 20 offshoots which come detatched from the “mother” plant and start a new individual. Still, as the weevil kills these rametes year after year the plant shrinks in size and eventually dies (T.M. Cooper personal communication, 2026). Thus, the result is the same, although it takes years rather than months.
Population s of both species have crashed. In the Enchanted Forest Sanctuary in Brevard County Cooper monitored population s of T. utriculata from March 2007 to June 2009. Eighty-seven percent of the plants died in the first six months. At 27 months, less than 3% of the original population remained. The primary reason the T. utriculata population was so rapidly destroyed was that the weevil attacked the largest plants, which, as noted above, were those on the on verge of producing seeds. [Cooper, Cave, and Frank 2024) It is now rare to see large T. utriculata plants. Medium-sized plants put out inflorescences. The weevil persists at low levels, so is able to feed on and reproduce on medium and small plants (T.M. Cooper personal communication, 2026).
A large and dense population of T. fasiculata was present in Loxahatchee National Wildlife Refuge (Palm Beach County) in 2002 to 2005. Almost every tree had multiple T. fasciculata plants; many were huge with multiple pups. When Cooper revisited about 10 years later, T. fasciculata plants were very sparse, large plants very rare; none was really large (T.M. Cooper personal communication, 2026).
There appears to be no more recent information about the status of T. utriculata. Patrick Gordon of the Florida Department of Agriculture and Consumer Services (personal communication, June 2026) reports that FDACS does not have an active program addressing the weevil.
Other bromeliads at risk
There is considerably more information about another endangered bromeliad, Guzmania monostachia. Krupar et al. (2023) report that G. monostachia has a broader distribution than other species in the genus, stretching across northern South America, Central America, the Caribbean, as well as southern Florida. As the northernmost population, the Florida population might harbor unique genetics important for the species’ adaptation to climate change.
Currently, G. monostachia is found in six fragmented and disjunct populations in five areas in Florida; the species has apparently been extirpated from four other sites by habitat loss, not depredations by the weevil. One set of habitats is in wetland sloughs on the peninsula’s west coast on the peninsula’s west coast. These forests comprise pond apple (Annona glabra) and Florida ash (Fraxinus caroliniana); Kupar et al. (2023) do not mention whether this species is vulnerable to the emerald ash borer, which has not yet been detected in Florida. These ash-pond apple sloughs support the largest population of G. monostachia in Fakahatchee Strand State Preserve, in Collier County in Southwest Florida. Fakahatchee Strand Preserve is Florida’ oldest and largest state park. Before M. callizona arrived, the bromeliad’s population was estimated to exceed two million individuals. Their number has been halved. Also, since M. callizona prefers larger plants, the proportion of reproductively mature individuals had been reduced from roughly 50% to only 10–20% by 2021.
T.M. Cooper reports (pers. comm. 2026) that weevil damage to Guzmania monostachia at Fakahatchee Strand Preserve was as great and rapid as that to T. utriculata. She fears this species might also be extirpated eventually.
The adjacent Big Cypress National Preserve is home to two populations of G. monostachia; they are separated by ~2,900 km2 so there is no interaction between them. The northern population consists of ~ 200 individuals, the southern population comprises ~ 1000 individuals.
Guzmania monostachia is in an even more precarious situation on the eastern side of the peninsula: tiny populations (two or three individuals) are found in three locations: Everglades National Park, Fuchs (formerly Sykes) Hammock Preserve, and Meissner Hammock Preserve.
Cooper monitored a very small population of Tillandsia paucifolia in St. Sebastian River Bluff Preserve (on the border of Indian River and Brevard counties) in the early years of the 21st Century. Of 13 plants observed, one had been killed by the weevil. She documented damage on T. simulata and T. variabilis, but the overall impact is unknown. There is no information re: T. flexuosa and T. pruinosa (T.M. Cooper pers. comm. 2026)
Management
In nurseries, the weevil can be controlled using an insecticide labeled for beetle adults and grubs. This recommendation is not based on specific data, because no chemical trials of any pesticide carried out. In natural areas, chemical control is not feasible because the epiphytes are not accessible from the ground. More importantly, in state and county parks use of chemical pesticides is not acceptable because of the probability of non-target effects.
Scientists seeking to protect vulnerable bromeliads initially focused on classical biocontrol. They made 16 expeditions to Mexico and Central and South America from 1992 to 2010 searching for natural enemies of the weevil. They discovered only one potential biocontrol agent, a parasitoid tachinid fly, Lixadmontia franki. The fly was found attacking a closely related weevil, M. quadrilineatus, on bromeliads in Honduran cloud forests. A fly colony was established in the University of Florida’s quarantine laboratory and research on fly-weevil interactions was conducted for several years. Releases into the environment were begun after the scientists obtained Federal and State permits in 2007. More than 3,100 flies were released from the end of June 2007 to 2014 (Cave 2008). However, the flies failed to establish. So this approach is no longer being pursued (Cooper, Cave, and Frank (2024); T.M. Cooper personal communication, June 2026).
In 2010, during one of the expeditions to Belize seeking additional biocontrol agents, Dr. Frank and D. Giardina of the Florida Fish and Wildlife Conservation Commission observed that the significant population of weevils had no apparent detrimental effect on bromeliads identified as Tillandsia utriculata (although there is some disagreement on this taxoo=nomy). Cooper, Cave, and Frank (2024) undertook a study to determine how the bromeliad could coexist with Metamasius callizona in Belize while being so vulnerable in Florida. They compared life cycle parameters (oviposition and pupation rates, egg hatch rate, adult emergence and size, and developmental time) of weevils from Florida and Belize. They also observed how populations of the weevil from Florida fared on three hosts, pineapple (Ananas comosus) and T. utriculata collected from Florida and Belize, and compared that performance to weevils from Belize. Finally, they quantified the hosts’ nutritional content using two measures (percent soluble solids and leaf toughness).
Their most important finding is that larval weevils from Florida could not develop past the third instar on leaves of the T. utriculata from Belize. They concluded that the Belize bromeliad’s leaves had lower nutrient availability – measured as percent of soluble solids – and were tougher than the leaves from Florida T. utriculata. The weevil larvae starved.
Based on this finding, Cooper, Cave, and Frank (2024) recommend that authorities introduce T. utriculata plants from Belize to Florida’s forests and allow them to colonize and/or hybridize naturally with Florida’s remaining plants. An alternative would be to breed hybrid Tillandsia in the lab and release them into Florida’s forests. They cite as examples of similar approaches introduction of mountain lions from elsewhere on the continent to create genetic diversity in populations of the highly endangered Florida panther, and a similar interspecific hybridization project for corals in the genus Acropora. The American Chestnut Foundation has also worked to integrate genetic material from Asian chestnuts into American chestnut (Castanea dentata) to build tolerance to the chestnut blight fungus (Cryphonectria parasitica).
USFS scientists and managers developed a conservation priority-setting framework for forest tree species at risk from pest & pathogens and other threats. The Project CAPTURE (Conservation Assessment and Prioritization of Forest Trees Under Risk of Extirpation) uses FIA data and expert opinion to group tree species under threat by non-native pests into vulnerability classes and specify appropriate management and conservation strategies. The scientists prioritized 419 tree species native to the North American continent. The analysis identified 15 taxonomic groups requiring the most immediate conservation intervention because of the tree species’ exposure to an extrinsic threat, their sensitivity to the threat, and their ability to adapt to it. Each of these 15 most vulnerable species, and several additional species, should be the focus of both a comprehensive gene conservation program and a genetic resistance screening and development effort. Phytophthora root rot is not known to be a threat to any of these 15 most vulnerable species. Mexican bromeliad weevil does not threaten any of these 15 most vulnerable species.
Sources
Cave RD. 1997. Admontia sp., a potential biological control agent of Metamasius callizona. J Brom Soc. 47:244-249.
Cave RD. 2008. Biological control of the Mexican bromeliad weevil. Biocontrol News and Information 29(1):1N-2N.
Cooper TM. 2006. Ecological and demographic trends and patterns of Metamasius callizona (Chevrolat), an invasive bromeliad-eating weevil, and Florida’s native bromeliads [Master’s thesis]. [Gainesville (FL)]: University of Florida. 69 p.
Cooper, T.M., R.D. Cave, and J.H. Frank. 2023. Potential bottom-up control of Metamasius callizona in Florida, USA. Entomologia Experimentales et Applicata. 2024. 172;4090421
Frank JH. 1983. Bromeliad phytotelmata and their biota, especially mosquitoes. In: Frank JH, Lounibos LP, editors. Phytotelmata: terrestrial plants as hosts for aquatic insect communities. Medford (NJ): Plexus. p. 101-128.
Frank JH. 1996. Bromeliad biota: history of Metamasius callizona Florida [online]. Gainesville (FL): University of Florida [cited 2010 Feb 1]. Available from https://www.entnemdept.ufl.edu/frank/bromeliadbiota/wvbrom6.htm
Frank JH, Cave RD. 2005. Metamasius callizona is destroying Florida’s native bromeliads. In: Hoddle MS, editor. USDA Forest Service Publication FHTET-2005-08. Vol 1. Second International Symposium on Biological
Control of Arthropods; 2005 Sep 12-16; Davos, Switzerland. Washington D.C.: USDA Forest Service. p. 91-101.
Frank JH, Fish D. 2008. Potential biodiversity loss in Florida bromeliad phytotelmata due to Metamasius callizona (Coleoptera: Dryophthoridae), an invasive species. Florida Entomol. 91(1):1-8.
Frank JH, Thomas MC. 1994. Metamasius callizona (Chevrolat) (Coleoptera:Curculionidae), an immigrant pest, destroys bromeliads in Florida. Can Entomol.126(1):673-682.
Krupar, S., A.A. Naranjo, G. Godden, N. Cellinese. The Fate of Guzmania monostachia in Florida Rests with Humans. Diversity 2023, 15, 525. https://doi.org/10.3390/d15040525
Potter, K.M., Escanferla, M.E., Jetton, R.M., Man, G., Crane, B.S., Prioritizing the conservation needs of US tree spp: Evaluating vulnerability to forest insect and disease threats, Global Ecology and Conservation (2019), doi: https://doi.org/10.1016/
Salas J, Frank JH. 2001. Development of Metamasius callizona (Coleoptera:Curculionidae) on pineapple stems. Florida Entomol. 84(1):123-126.
Wood DM, Cave RD. 2006. Description of a new genus and species of weevil parasitoid from Honduras (Diptera: Tachinidae). Florida Entomol. 89(2):239-24.