Risk Posed by Pesticides to Aquatic Organisms in Rivers of Northern Inland New South Wales,Australia

An ecological assessment was conducted to determine the risk posed by agricultural pesticides to inland rivers of north-west New South Wales (NSW), Australia. A preliminary screening of 30 pesticides provided a short-list of eight for further investigation (atrazine, chlorpyrifos, diuron, endosulfan, fluometuron, metolachlor, profenofos, prometryn). Selection was based on chemical characteristics, toxicity, detection frequencies and environmental concentrations. Hazard quotients were calculated for both spray and non-spray seasons. Where possible, hazard quotients were calculated for both acute and chronic exposures for crustaceans, insects, micro-organisms, molluscs, plants and vertebrates. Chlorpyrifos, endosulfan and profenofos posed a high hazard (HQ > 0.5). A probabilistic risk analysis indicated that chlorpyrifos, endosulfan and profenofos posed a risk from acute exposure during the spray season, while endosulfan also posed a risk from chronic exposure during the spray season. The risks posed by profenofos and chlorpyrifos were characterised by a low probability of detection, but these detections affected a high percentage of species. The risks posed by acute and chronic exposures of endosulfan were characterised by a high probability of detection, but only a limited number of these detections affected a high percentage of species. Risk during the non-spray season was not assessed, as the detection of pesticides was infrequent during this period.     

Evaluation of resistance to different insecticides in field strains of Helicoverpa armigera (Lepidoptera: Noctuidae) in Punjab, Pakistan

Susceptibility of field populations of Helicoverpa armigera (Lepidoptera: Noctuidae) from Punjab, Pakistan to selected insecticides was evaluated using the leaf dip method. The resistance factors varied between populations. The general trends were low to moderate resistance to endosulfan; very low to low resistance to chlorpyrifos and profenofos; very low resistance to spinosad, indoxacarb and thiodicarb; moderate to high resistance to bifenthrin; high to very high resistance to cypermethrin; and very high resistance to lambda-cyhalothrin. Integrated pest management strategies aimed at reducing pesticide application, such as rotating the conventional insecticides having low resistance with newly developed synthetic insecticides and conserving natural enemies, are recommended.     

敌敌畏、丙溴磷及丁草胺在菜用大豆上的安全性试验

采用气相色谱法及田间示范试验方法,并根据GB2763-2005、日本及欧盟规定的最高残留限量(MRL)要求,研究了敌敌畏、丙溴磷与丁草胺3种农药在菜用大豆上的安全性。结果表明,敌敌畏的安全间隔期为3 d,在菜用大豆上进行合理使用最终产品质量是安全的;丙溴磷产品内销(参照甘蓝)的安全间隔期为18 d,出口日本及欧盟的安全间隔期为28 d,在菜用大豆生长中后期及后期使用不当易引起最终产品农残超标;在菜用大豆种植后当天,合理施用丁草胺,其最终产品质量是安全的。