At present, 576 weevil species are known from Florida, of which 526 are native, and a few of them are pests. Among the 50 species of foreign origin, 5 were introduced deliberately as biological control agents of weeds; the other 45 are immigrants (O'Brien 1995).
Among the immigrants are some important pests, many of which probably arrived as stowaways in cargoes of plants and plant materials, were not detected by agricultural inspection, and established populations in Florida. Eleven of them, reported in the literature for the first time since 1970, are listed by Frank & McCoy (1992). Alfalfa weevil, Apopka weevil (also called sugarcane rootstalk borer weevil), boll weevil, Fuller rose weevil, pepper weevil, and sweetpotato weevil are other pests that probably arrived as hitchhikers in cargoes. They are among the relatively few weevil species in Florida that have been given English names, and that is because people encounter them commonly because their populations are large and they cause damage to crop plants. Hundreds of species of native weevils have not been given English names, and are poorly known, because they are interesting only to a few entomologists, not to the general public.
Five weevil species were introduced and released for biological control of aquatic weeds (hydrilla, waterhyacinth, waterlettuce, and watermilfoil) (Frank & McCoy 1993) and another more recently for control of Melaleuca. Each of them is a specialized feeder on one of those weed species.
Florida now has three species of the genus Metamasius. One, M. mosieri, is native or at least has been in Florida for a long time. The second, M. hemipterus, is an immigrant detected in 1984 and attacks palms, banana plants, sugarcane, and occasionally pineapple; it has a wider range of host plants than do most Metamasius species. The third, M. callizona, detected in 1989, is also an immigrant, and attacks bromeliads. A fourth, M. monilis, which attacks orchids, was also an immigrant, but was eradicated soon after its initial detection in a greenhouse in 1972. Rapid action by the Division of Plant Industry (DPI) of the Florida Department of Agriculture and Consumer Services eradicated M. monilis soon after it was detected, but detection was too late for M. hemipterus and M. callizona