40%乐桑乳油防治桑尺蠖效果的游程检测

为了筛选替代甲胺磷且适合于桑园害虫化学防治的新农药,测定了40%乐桑乳油对桑尺蠖的室内毒力,用非参数统计方法中的游程检测法,分析了2003-2004年江西、山东、江苏和浙江4省地的防治效果数据,构建了不同年份地域田间防治药效的综合评价方法。结果表明:40%乐桑乳油对桑尺蠖的LC50为175.40mg/L,高于50%甲胺磷乳油的LC50值(315.69mg/L),以267mg/L剂量喷药后的第1、7天,400mg/L喷药后第1、3、7天的防治效果依次为78.54%、81.78%和87.62%、90.96%、91.01%;50%甲胺磷乳油以500mg/L剂量喷药后的第1、3、7天,防治效果分别为79.85%、85.52%和80.63%。结果显示40%乐桑乳油可以替代甲胺磷用于防治桑园害虫。     

高尔夫球场湖水中毒死蜱和溴氰菊酯的残留分析

为探讨高尔夫球场施用农药对水体环境的影响,本研究采用优化后的固相萃取-气相色谱法,按不分流进样,梯度升温的色谱条件检测了高尔夫球场内湖水中的毒死蜱和溴氰菊酯,结果表明：毒死蜱和溴氰菊酯色谱峰尖锐且对称,色谱分离较好,0.05 mg·L^-1,0.1 mg·L^-1,0.2 mg·L^-1色谱分离的重现性好,灵敏度高,加标回收率及相对偏差符合农药残留分析的要求;施用农药前1 d,球场内湖中毒死蜱和溴氰菊酯均未检出,施用农药后第1 d和第4 d毒死蜱和溴氰菊酯的检测值均出现超标,且第4 d毒死蜱和溴氰菊酯的单因子污染指数比第1 d的高,但第8 d毒死蜱和溴氰菊酯的单因子污染指数则小于1或未被检出。该结果旨在为高尔夫球场水体的生态风险评估提供科学依据。     

In vivo chlorpyrifos induced oxidative stress: Attenuation by antioxidant vitamins

Chlorpyrifos (O,O′-diethyl O-3,5,6-trichloro-2-pyridyl phosphorothionate, CPF) exposure in rats causes elevation in the levels of thiobarbituric acid reactive substances (TBARS) and inhibition of acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT), and glucose-6-phosphate dehydrogenase (G6PDH) activities in the liver, kidney, spleen, and brain of rats. The sublethal exposure of CPF also causes decrease in the levels of reduced glutathione (GSH) and consequent increase in oxidized glutathione (GSSG) levels, resulting in a significant decrease in GSH/GSSG ratio in all the rat tissues tested. These results clearly indicate that CPF exposure causes oxidative stress in rat tissues. However, CPF exposure to rats fed with antioxidant vitamins (vitamin A, E, and C) for 1 month, prevented derangement of these antioxidant parameters. The accumulation of TBARS was also not seen in tissues of rats fed with antioxidant vitamins on CPF exposure. AChE activity, which is sensitive to OP pesticides, was also not significantly inhibited in these rats on CPF exposure. The present findings clearly show that oral intake of a mixture of vitamin A, E, and C, protects the rats from CPF induced oxidative stress and suggesting that this treatment alleviates the toxicity of this pesticide.     

毒死蜱在土壤中的环境行为研究

按照“化学农药环境安全评价试验准则”的规定,研究了毒死蜱在土壤中的主要环境行为——吸附性、移动性、挥发性及降解的特性。结果表明,土壤具有较强的吸持毒死蜱农药的能力,吸附常数(Kd)为：壤土213.51,粘土182.82和砂土157.01;毒死蜱属于在壤土、砂土中不易移动,在粘土中不移动的农药品种;毒死蜱在壤土和粘土属难挥发,在砂土属中挥发;毒死蜱在壤土、粘土和砂土中的降解半衰期分别为23.9d、12.6 d和9.8 d,属于易土壤降解的农药品种。     

氟虫腈·毒死蜱18%种子处理微囊悬浮剂对花生蛴螬防治研究

本研究以氟虫腈·毒死蜱18%种子处理微囊悬浮剂为对照药剂,测定了氟虫腈·毒死蜱18%种子处理微囊悬浮剂包衣花生种子后氟虫腈和毒死蜱在花生根际土壤和根系中的剂量动态及对花生蛴螬的防治效果。实验结果表明包衣种子播种后微囊化可以显著延缓毒死蜱和氟虫腈在花生根际土壤中的降解,在相同剂量下氟虫腈·毒死蜱18%种子处理微囊悬浮剂处理中在花生根际土壤和根系中氟虫腈和毒死蜱含量均显著高于非微囊化制剂。在药种比1∶100或1∶50条件下,用氟虫腈·毒死蜱种子处理微囊18%悬浮剂对花生种子包衣即可在整个花生生育期对蛴螬有效控制,防治效果在70%以上。     

近红外光谱技术检测溶液中毒死蜱含量试验

用近红外光谱(NIR)方法对溶液中极微量毒死蜱进行了测定,通过模拟蔬果成分背景,配制了47个混合液样本,其中37个样本为含有质量比为0.005～0.100mg/kg毒死蜱的混合液样本,用于定量分析,同时10个不含农药的混合液样本,用于聚类分析.结果表明,近红外光谱法对混合溶液中质量比在0.008～0.090mg/kg之间的毒死蜱取得良好的检测效果.     

50%毒·氯乳油对韭菜迟眼蕈蚊幼虫的室内毒力及田间防效

本文采用室内与田间试验相结合的方法,研究了50％毒·氯乳油对韭菜迟眼蕈蚊幼虫的杀虫效果。结果表明其对韭菜迟眼蕈蚊幼虫具有良好的杀虫效果,室内毒力测定LC50= 44．42mg／L;田间防治效果理想,且表现出良好的速效性及持效性,其中3 000g／hm2剂量, 药后3d的防治效果达到79．26％,药后20d防治效果仍然可以维持在80％以上。     

桑园治虫新药40%“乐桑”乳油对家蚕的残毒期测定

以266 mg/L 40%“乐桑”乳油在桑园里喷雾治虫,春季分别在喷药后第19、20、21天,秋季分别在喷药后第17、18和19天采叶喂蚕,统计2个季节各处理与相应对照的虫蛹生命率、茧层量和全茧量。利用M ann-W h itney U精确p值的Monte Carlo估计值进行统计检验,结果表明:该药对家蚕的残毒期春季为20 d,秋季为18 d。     

展着剂提高毒死蜱对桑白蚧成虫防效的研究

蚧壳虫是一类难于防治的害虫,种类多、发生范围广,严重影响果树生产。蚧壳虫防治的难点在于若虫时期短,防治时期极易错过,而成虫雌蚧体外被有蜡质介壳,化学药剂不易穿透导致药效极低。为了提高化学药剂防治蚧壳虫的效果,进行了化学药剂筛选、展着剂筛选以及化学药剂与展着剂混合使用的筛选试验。结果表明：毒死蜱1 000倍液与展着剂甲基三氧乙基硅烷2 000倍液混合使用,对桑白蚧成虫防治效果最好,相对防效达81.21%。     

Liver profile of rats after long-term ingestion of different doses of chlorpyrifos

Male Wistar rats were separated into three groups of 25 each. Animals in group A (GA) served as control, group B (GB) were daily administered orally chlorpyrifos at a dose of 5 mg/kg b wt and animals in group C (GC) received daily an oral administration of chlorpyrifos (Anu Products Ltd., India) at a dose of 10 mg/kg b wt. Rats were sacrificed 24 h after last dose on 1st, 2nd, 4th, 6th, and 8th week after initiation of the experiment. Small pieces of liver were extirpated and fixed in aqueous Bouin’s solution. The tissues thus fixed were routinely processed for histological studies. The present study showed that the histopathological changes were caused in liver of rats by chlorpyrifos administration. The changes noticed were mainly hepatocytic vacuolation, degeneration of hepatocytes and their nuclei, hyperchromatic and hypertrophied nuclei at earlier stage of treatment, sinusoidal dilation and focal necrosis. However, variable intensities of these changes were noticed depending upon the doses and duration of the treatment.