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An excessive proportion of adventive (=“non-indigenous”) species in a community has been called “biological pollution.” Proportions of adventive species of fishes, amphibia, reptiles, birds and mammals in southern Florida range from 16% to more than 42%. In Florida as a whole, the proportion of adventive plants is about 26%, but of insects is only about 8%. Almost all of the vertebrates were introduced as captive pets, but escaped or were released into the wild, and established breeding populations; few arrived as immigrants (= “of their own volition”). Almost all of the plants also were introduced, a few arrived as immigrants (as contaminants of shipments of seeds or other cargoes). In contrast, only 42 insect species (0.3%) were introduced (all for biological control of pests, including weeds). The remainder (about 946 species, or 7.6%) arrived as undocumented immigrants, some of them as fly-ins, but many as contaminants of cargoes. Most of the major insect pests of agriculture, horticulture, human-made structures, and the environment, arrived as hitchhikers (contaminants of, and stowaways in, cargoes, especially cargoes of plants). No adventive insect species causing problems in Florida was introduced (deliberately) as far as is known. The cause of most of the so-called biological pollution is the public's demand for “pet” animals and “ornamental” plants of foreign origin, the public's environmental irresponsibility in handling these organisms, the dealers' willingness to supply these organisms for cash, and governments' unwillingness to stem the flow of a lucrative commerce. The cause of almost all of the remaining part is flight, walking, swimming, and rafting from adjoining states and from nearby countries in the Caribbean, Mexico and Central America. The introduction of specialized insect biological control agents, although it contributes to biological pollution, appears to be an environmentally-sound solution to the much greater biological pollution caused by immigrant insects and introduced plants in Florida. Greater concern for insects as living things, or as integral parts of nature, coupled with increased understanding of how problem insects get into Florida, may foster a more even-handed approach to the reduction of biological pollution.

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Florida Entomologist, v. 78, issue 1, p. 1-15

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