The effects of diflubenzuron on a complex laboratory stream community

摘要: Effects were assessed on the total biological community in complex laboratory streams caused by continuous exposure to diflubenzuron (1-(4-chlorophenyl)-3-(2,6-difluorobenzoyl) urea). The insect fauna suffered direct toxic effects at concentrations of 1.0μg/L and greater. algal fungal floras mildly affected same concentrations; apparently indirect response reduced herbivore shredder components fauna. No observed bacteria, oligochaetes or gastropods, any test concentrations. Within fauna, differences sensitivities observed: mayflies stoneflies 1.0μg/L, dipterans 10.0μg/L, coleopterans unaffected caddisflies could not be determined due their failure become established stream systems. These between orders sensitivity, coupled with generation time, may reduce overall benefits insecticide. For example, if is used for chironomid control, result more severe longer lasting nontarget mayfly stonefly populations.