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|Section2= |Section6= }} Fipronil is a broad-use insecticide that belongs to the phenylpyrazole chemical family. Fipronil is a broad-spectrum insecticide that disrupts the insect central nervous system by blocking GABA-gated chloride channels and glutamate-gated chloride (GluCl) channels, resulting in central nervous system toxicity. This causes hyperexcitation of contaminated insects' nerves and muscles. Specificity of fipronil on insects may come from a better efficacy on GABA receptor, but also because GluCl channels do not exist in mammals.〔Raymond-Delpech V, Matsuda K, Sattelle BM, Rauh JJ, Sattelle DB (2005) Ion channels: molecular targets of neuroactive insecticides. ''Invert Neurosci'': 1-15.〕 ==Effects== Fipronil is a slow acting poison. When used as bait, it allows the poisoned insect time to return to the colony or harborage. In cockroaches, the feces and carcass can contain sufficient residual pesticide to kill others in the same nesting site. In ants, the sharing of the bait among colony members assists in the spreading of the poison throughout the colony. With the cascading effect, the projected kill rate is about 95% in three days for ants and cockroaches. Fipronil serves as a good bait toxin not only because of its slow action, but also because most, if not all, of the target insects do not find it offensive or repulsive. Toxic baiting with fipronil has also been shown to be extremely effective in locally eliminating German wasps (commonly called yellow jackets in North America). All colonies within foraging range are completely eliminated within one week. Wildlife impacts include the following: * Fipronil is highly toxic to fish and aquatic invertebrates. Its tendency to bind to sediments and its low water solubility may reduce the potential hazard to aquatic wildlife. * Fipronil is toxic to bees and should not be applied to vegetation when bees are foraging.〔 * The ecological effects data show that fipronil is highly toxic to upland game birds on an acute oral basis, very highly toxic on a subacute dietary basis, and is practically non-toxic to waterfowl on both an acute and subacute basis. The chronic (avian reproduction) studies show no effects at the highest levels tested in mallards (NOEC) = 1000 ppm) or quail (NOEC = 10 ppm). The metabolite MB 46136 is more toxic than the parent to avian species tested (very highly toxic to upland game birds and moderately toxic to waterfowl on an acute oral basis). Fipronil is very highly toxic to bluegill sunfish and highly toxic to rainbow trout on an acute basis. The results of a fish early life-stage toxicity study in rainbow trout show that fipronil affects larval growth with a NOEC of 0.0066 ppm and an LOEC of 0.015 ppm. The metabolite MB 46136 is more toxic than the parent to freshwater fish (6.3 times more toxic to rainbow trout and 3.3 times more toxic to bluegill sunfish). Based on an acute daphnia study using fipronil and three supplemental studies using its metabolites, fipronil is characterized as highly toxic to aquatic invertebrates. An invertebrate life cycle daphnia study showed that fipronil affects length in daphnids at concentrations greater than 9.8 ppb. A life cycle study in mysids shows fipronil affects reproduction, survival and growth of mysids at concentrations less than 5 pptr. Acute studies of estuarine animals using oysters, mysids, and sheepshead minnows shows that fipronil is highly acutely toxic to oysters and sheepshead minnows, and very highly toxic to mysids. Metabolites MB 46136 and MB 45950 are more toxic than the parent to freshwater invertebrates (MB 46136 is 6.6 times more toxic and MB 45950 is 1.9 times more toxic to freshwater invertebrates).〔(【引用サイトリンク】 author = United States Environmental Protection Agency Office of Prevention, Pesticides and Toxic Substances )〕 Fipronil is also used as the active ingredient in flea control products for pets, field pest control for corn, golf courses and commercial turf, although flea populations appear to be developing a genetic resistance to its effects. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Fipronil」の詳細全文を読む スポンサード リンク
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