8种药剂对黄蓟马的室内生物活性及田间防效

[目的]筛选防治黄蓟马的有效药剂及用量。[方法]选择8种杀虫剂,采用浸叶法对黄蓟马成虫进行室内生物活性测定,并结合防效试验进行效果验证。[结果]室内生物活性测定结果表明:25%噻虫嗪WG、10%吡虫啉WP、50%噻嗪酮SC和1.80%阿维菌素EC对黄蓟马有较高的活性。田间药效结果表明:10%吡虫啉WP 4.14 g a.i./hm2在施药3 d后防效最好,达到92%;1.80%阿维菌素EC 1.20 g a.i./hm2和25%噻虫嗪WG 5.13 g a.i./hm2在施药7 d后防效最好。[结论]25%噻虫嗪WG和1.80%阿维菌素EC可推荐为防治黄蓟马的首选药剂,2者属于不同类型的杀虫剂,适合交替使用,防止黄蓟马快速产生抗药性。     

以天然产物为先导化合物开发的农药品种(Ⅱ)--杀虫杀螨剂

概述了以天然产物为先导化合物进行的杀虫杀螨剂的创制研究以及开发的品种，涉及的化合物或类别如氨基甲酸酯、拟除虫菊酯、沙蚕毒素类似物、吡咯类、新烟碱类、保幼激素类似物、双酰肼(蜕皮激素类似物)、鱼藤酮类似物、二烯酰胺、季酮酸类、嘧螨酯、灭螨醌等，并对部分化合物的生物活性和创制经纬等进行了概述。     

棉铃宝等4种农药防治棉铃虫的效果

田间试验和室内试验表明，５０％棉铃害宝乳油对棉铃虫幼虫和卵，２６％灭铃皇乳汪对棉铃虫幼虫均具理想的防治作用。喷施棉铃害７５毫升／６６７米＾２后７天，虫卵综合防效达９４．４％，喷施棉铃宝１００倍液和灭铃皇１００倍液后５天，对２－１龄幼虫的防治效果分别在９６．７％和９３．３％。     

潜在杀虫剂6-Cl-PMNI衍生物的合成

合成了一系列6-Cl-PMNI衍生物,这些衍生物具有潜在的杀虫活性。衍生物的结构经过核磁氢谱、元素分析、红外验证。本研究为6-Cl-PMNI的进一步研发和应用提供了参考。     

Ultrastructural and developmental toxicity of potato and tomato leaf extracts to beet armyworm,Spodoptera exigua (lepidoptera: noctuidae)

Beet Armyworm, Spodoptera exigua is a herbivorous moth and a serious pest of many economically important plants, which are used as food sources. Because of rigorous standards of food quality, usage of synthetic insecticides in crop protection, against pests, is limited. Solanaceae plant extracts may be a relatively cheap source of efficient natural insecticides that can limit usage of synthetic substances. Their biological activity is not fully known. In particular, ultrastructural studies, using transmission electron microscopy, are not usual. In the present article we describe the effects of sublethal concentrations of tomato and potato leaf extracts against S. exigua. Acute lethal effects were not observed. Both extracts exerted similar effects within midgut and fat body cells. Midgut cells were not significantly altered while fat body cells showed prominent swelling of nuclear envelope and endoplasmic reticulum, vacuolization of mitochondria and fusion of fat droplets. These changes were much more intensive within groups exposed to potato than tomato extracts at highest concentration at least. Light microscopy was used to observe and document developmental alterations of S. exigua exposed to potato and tomato leaf extracts. Potato leaf extracts significantly decreased hatching success and caused morphological malformations of imagoes. Among them, malformations of wings were the most prominent. Interestingly, these effects were not observed within populations exposed to tomato extracts at highest concentration at least.     

New Eugenol Derivatives with Enhanced Insecticidal Activity

Eugenol, the generic name of 4-allyl-2-methoxyphenol, is the major component of clove essential oil, and has demonstrated relevant biological potential with well-known antimicrobial and antioxidant actions. New O-alkylated eugenol derivatives, bearing a propyl chain with terminals like hydrogen, hydroxyl, ester, chlorine, and carboxylic acid, were synthesized in the present work. These compounds were later subjected to epoxidation conditions to give the corresponding oxiranes. All derivatives were evaluated against their effect upon the viability of insect cell line Sf9 (Spodoptera frugiperda), demonstrating that structural changes elicit marked effects in terms of potency. In addition, the most promising molecules were evaluated for their impact in cell morphology, caspase-like activity, and potential toxicity towards human cells. Some molecules stood out in terms of toxicity towards insect cells, with morphological assessment of treated cells showing chromatin condensation and fragmentation, which are compatible with the occurrence of programmed cell death, later confirmed by evaluation of caspase-like activity. These findings point out the potential use of eugenol derivatives as semisynthetic insecticides from plant natural products.     

Magnetic nanocellulose hybrid nanoparticles and ionic liquid for extraction of neonicotinoid insecticides from milk samples prior to determination by liquid chromatography-mass spectrometry

A simple and rapid microextraction procedure is reported on the use of ionic liquid in combination with magnetic nanocellulose hybrid nanoparticles. The procedure is ultrasound-assisted and applicable to selective preconcentration of neonicotinoid insecticides from milk samples, prior to being analysed by liquid chromatography-mass spectrometry. The extraction procedure uses small volume of organic solvents (<1 mL), and there is no need for centrifugation. In the experimental approach the ionic liquid was quickly disrupted by an ultrasonic probe and dispersed in milk samples in a cloudy form. At this stage, neonicotinoid insecticides were extracted into the fine droplets of ionic liquid. Then small amounts of magnetic nanocellulose hybrid nanoparticles were dispersed into the sample solutions to adsorb the ionic liquid containing the analytes and phase separation was completed. The ionic liquid allowed the microextraction of the analytes and a small volume of acetonitrile was used for elution. Magnetic nanocellulose favoured the adsorption of the ionic liquid with the analytes and improved the final recovery with respect to the use of simple magnetic nanoparticles as a sorbent material. Under the optimum conditions, decision capabilities were achieved in the 0.02–0.06 mg kg^?1 range, with recoveries between 91.0% and 109.5%.     

The decrease in pesticides in fruit and vegetables during commercial processing

Samples of tomatoes, peppers, asparagus, spinach and peaches were exposed to three insecticides (acephate, chlorpyrifos and cypermethrin), three ethylenebisdithiocarbamate fungicides (mancozeb, maneb, propineb) and the tetramethyldithiocarbamate fungicide thiram to study the effect of commercial processing on the residues. In most cases, canning operations led to a gradual decrease in residue levels in the finished products, particularly through washing, blanching, peeling and cooking processes. The results indicated that washing plus blanching led to more than 50% loss in pesticide residues, except for in peaches. Ethylenebisdithiocarbamates (EBDCs) were completely removed from tomatoes and spinach by washing followed by hot water blanching. The total amount of pesticide removed by all of the combined canning operations ranged from 90 to 100% in most products. Pepper retained 61% of chlorpyrifos but these residues disappeared during 3‐month storage of finished cans. Acephate showed a surprising tenacity in peaches, as 11% of the original residues were still present in 2‐year stored cans.     

防治稻水象甲成虫药剂室内筛选

[目的]2010年在贵州首次发现检疫性害虫稻水象甲(Lissorhoptrus oryzophilus Kusche1),为了快速筛选出高效、低毒化学药剂,为贵州省稻水象甲成虫化学防治提供依据,采集田间稻水象甲成虫进行室内药剂生测筛选试验。[结果]48%毒死蜱EC对稻水象甲成虫防效最好,药后1 d各剂量处理防效在77%以上,药后3 d各剂量处理防效均达100%;其次为40%氯虫苯甲酰胺.噻虫嗪WG,药后1 d各剂量处理防效在72%以上,药后3 d各剂量处理防效在87%以上;10%醚菊酯SC在剂量为150、180 g a.i./hm2时,对稻水象甲成虫均有较好的防治效果。[结论]以上3种药剂防治稻水象甲成虫活性高且速效性好,可作为防治稻水象甲成虫的选择药剂。     

蔬菜中氨基甲酸酯类农残的HPLC测定方法

用高效液相色谱-柱后衍生荧光法测定了蔬菜中7种氨基甲酸类杀虫剂及其3种代谢物残留量.研究结果表明,方法的最低检测限范围为0.005～0.011mg/kg,回收率的范围是86.40%～97.00%,相对标准偏差（RSD）＜10%.