Risk assessment of etofenprox (Vectron) on non-target aquatic fauna compared with other pesticides used as Simulium larvicide in a tropical environment.
Within the rotational scheme developed by the Programme to fight the resistance of Simulium damnosum to chemical larvicides, there was an operational gap at discharges between 5 and 70 m3 s(-1) for the treatment of rivers where resistance to organophosphates was present. The use of permethrin and carbosulfan was precluded because of risk of environmental impact and, Bacillus thuringiensis ser. H-14 treatments were not envisageable due to cost and logistics constraints. Among the possible complementary groups of larvicides tested, the pseudo-pyrethroids, held promise, because of a mode of action similar to that of pyrethroids, but along with a usually lower toxicity for fish. Etofenprox, one of the pseudo-pyrethroids tested, shows a global detachment of non-target insects in 24 h close to that of pyraclofos, an organo-phosphorus compound (27 against 23%). In laboratory conditions, six times the operational dose which is 0.03 mg l(-1) 10 min, is needed to cause 50% mortality of Caridina sp. (a small shrimps species) and 30 times this same dose for 95% mortality. For fish species, a safety margin of 400-800 times the operational dose is observed for Oreochromis niloticus and 200-400 times for Tilapia zillii.
WHO, Onchocerciais Control Programme in West Africa, Ouagadougou, Burkina Faso. yameogo@ocp.oms.bf
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D000818:Animals; D001413:Bacillus thuringiensis / Q000187:drug effects / Q000502:physiology; D002219:Carbamates / Q000633:toxicity*; D003445:Crustacea; D017753:Ecosystem; D005399:Fishes; D007300:Insect Control; D007313:Insecta; D007306:Insecticides / Q000633:toxicity*; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D026023:Permethrin; D011157:Population Dynamics; D011722:Pyrethrins / Q000633:toxicity*; D012843:Simuliidae; D018675:Toxicity Tests; D014874:Water Pollutants, Chemical
D002219:Carbamates; D007306:Insecticides; D011722:Pyrethrins; D014874:Water Pollutants, Chemical; C076840:ethofenprox; D026023:Permethrin; C035038:carbosulfan